ROBOCON - 2009

ELECTRICAL ASPECTS

Motor Drivers1. Sabertooth Link -

http://www.dimensionengineering.com/Sabertooth2X10.htm

Dual motor driver Current: 10x2 A Voltage: upto 24V Price: $80 tried and tested, no problems

reported yet.

2. PololuLink-http

://www.robotshop.ca/home/products/robot-parts/motor-controllers/brushed-motor-controllers/motor-controllers-by-interface/pwm-motor-controllers/pololu-dual-motor-driver-9a.html

Dual motor driverCurrent: 2x9 AVoltage: upto 36VPrice: $50current limit slightly lower than

sabertoothSeems less hardy than sabertoothCost effective, worth a try

3. Bakatronics MXA066

Link :- http://www.bakatronics.com/shop/item.aspx?itemid=581

Single motor driver Current: 1x30AVoltage: 12/24V Price: $30 (=$60 effectively

for dual motors)very high current limit (of no

use to us though)Cost effective (since some of

our applications may require only single motor control)

Website and documentation not very credible

SENSORS (IFM)1) OO5006 Link :- http://

www.ifm.com/products/IND/ds/OO5006.htm

Specification:-

6 channels for 6 glass fibre optics No mutual optical interference Graphic display Electronic lock & Function check output

Sensing range:-

0 ... 400mm (Through-beam sensor) 0 ... 200mm (Diffuse reflection sensor)

Dimensions:-123.9X76.5X70.7mm

2). OK5001Link :-

http://www.ifm.com/products/IND/ds/OK5001.htm

Used last year

Sensing Range: 0 - 120mm (Through-

beam sensor) 0 - 40mm (Diffuse

reflection sensor)

Dimensions:- 50X30X19mm

Lithium Ion Batteries

Energy to weight ratio

No memory effectSlow loss of charge

when not in use1 battery for each

microcontroller circuit is to be used

1. Panasonic

http://www.panasonic.com/industrial/battery/oem/chem/lithion/

Produce 3.6 V Weight – around 45 g Capacity – vary from 2.05 -

2.5 Ah Cylindrical Prismatic have lower capacityOther Manufacturers Ultralife – http://www.ultralifebatteries.

com/dealer_info.php?ID=505 Banglore, India

Lithium ion Battery ChargerSeparate charging

circuit required since they can be damaged if overcharged

Diptrace diagram of circuit is shown

DISTANCE SENSORSRequirementThe need of using distance sensors arose from

the fact that Carrier bot (Autonomous) needed a signal to start moving once the traveller bot completes the task of boarding the kago.

The obstacle(traveller bot) is approximately 50 cm from the sensor and well within the range of 80 cm which the distance sensor can successfully detect.

SHARP GP2D12 AVAILABILITY FEATURES5 sensors of the same

type are already available with us providing good number of backups.

The Sharp GP2D12 is an analog distance sensor that uses infrared to detect an object between 10 cm and 80 cm away. The GP2D12 provides a non-linear voltage output in relation to the distance an object is from the sensor and interfaces easily using any analog to digital converter.

ENCODERSRequirementsTask of synchronizing the cago height and angleMoving carrier bot after 2nd check point We are getting encoders from IFM and probably be

using them.

Incremental EncoderRU10456 encoders are already

availableDifferent from the

absolute in the sense they require only 2 sensors , hence cheaper

Work on 5V dc Can give accuracy upto

5000 counts per revolution

Absolute EncodersRN60262 encoders are availableThey require n contacts

for 2^n countsWork on 10-30V dc

EEPROMElectrically Erasable Programmable Read-Only

MemoryTo store small amounts of data that must be

saved when power is removed.We are using the serial interface to EEPROM.Price:-Freely available on microchip of any

memory size ranging from 128bit to 1Mb.

I²C™ Serial EEPROM

SPI Serial EEPROM