Week 13 Progress

Discussion

The major problem of this project is noise in electrical and electronic circuit. Generally, noise is interference frequency or signal has happened at electronics or electrical components. In every electrical or electronic device, noise is a common problem which, to reduce it, selection of good electronic and electrical components is important to minimize noise. Although in circuit design the method of noise suppressing has been implemented, noise can still happen. This is because; the way of the wiring of the whole circuitry and other things can still produce noise. Among the things that can cause noise are:

                    i.            Along the motor wires.

                  ii.            By radiation from the motor body and wiring.

                iii.            From the motor body through it’s mounting.

                iv.            It happens of component that does not can function or damaged.

Although noise can cause lots of problems to the system, it can’t be killed. These methods can be used to minimize the noise in the system are:

                    i.            Make sure the gear of motor free from corrosion and in generally good condition.

                  ii.            Make sure dirt cannot get into the motor especially through the ventilation holes.

                iii.            The wire of the motor supply current must be suitable such as multi core wire (ø3mm).

                iv.            Keep ‘hot’ wire far apart from each other.

‘Hot’ wires will generally be motor to controller and controller to the battery wires. The wires are considered hot because any two wires running parallel to each other for any distance interact because of mutual inductance and capacitance. If they must be in close proximity, screened cable must be used. For this whole project, other problems there were some identified either in mechanical and electrical parts. Problems of this project must be overcome to be sure function of project is the best and perfect. Others problems also can be found on this project are:

PROBLEMS	SOLUTION
Battery unsuitable because a current is lowest (1.2 amp).	This project using two power window motor which each motor can operate with minimum current (2 amp).To solve this problem, the high current battery must be use  to support both of power window motor (suggestion is 4 amp and above).
RPM of power window motor too high (3600 RPM for 12VDC).	For this project, selection of motor is important because the movement of this walker must be smoothly. To avoid this problem, RPM for this motor must be reduce by using the suitable gear motor (suggestion is 50RPM).

Week 12 Progress

Bill of Material (B.O.M)

NO	ITEMS	QUANTITY	PRICE (RM)
1	Walker	1	125.00
2	Power Window motor (12V)	2	260.00
3	Rubber wheel ( 6 inch diameter)	2	54.00
4	Castor wheel ( 2 inch diameter)	2	21.00
5	Relay (5V)	4	10.00
6	Relay ( 6V)	3	7.50
7	Relay (12V)	2	5.00
8	Resistor (10K)	10	1.00
9	Resistor (1K)	8	0.80
10	Capacitor	4	1.60
11	Crystal (20Mhz)	1	2.00
12	Diode	5	1.50
13	Transistor (Tip 41)	4	1.50
14	Lithium polymer battery (12VDC)	1	267.00
15	Universal charger	1	335.00
16	Box	1	20.00
17	Keypad switch	1	18.00
18	Microchip Base	1	12.00
19	Voltage indicator	1	67.00
20	Microchip	1	25.00
21	Voltage regulator LM7805	1	1.50
22	Wrapping cable	5 meter	9.00
	Estimation Cost (RM)		1412.40

Specification of Remote Sensing Walker

Item	Specification
Frame	Height : 95 cm Wide (up):30 cm x 50 cm Wide ( bottom): 45 cm x 55 cm
Rubber wheel	Dia.3.5 inch @8.89cm
Castor wheel	Dia.1.5 inch@ 3.81cm
Weight	7.8 kg
Hand switch box	7cm x 5cm
Remote control range	5 meter
Control panel box	25 cm x 20 cm
PIC battery	10VDC (1000mA)
Motor Battery	12VDC ( 4Amp)
Battery life	10 hours

         Result

 Below shown the finishing and final product oh the Handicapped Walker With Remote Control 

EXPERIMENT 1: Smooth Surface and Rugged Surface

This experiment is to determining the motion of the Handicapped Walker With Remote Control on the smooth surface and rugged surface. According to Boye (2008), rolling resistance sometimes called rolling friction or rolling drag, is the resistance that occurs when a round object such as a wheel on a flat surface. The rolling resistance is the force that resists the rolling of a wheel or other circular object along a surface caused by deformations in the object and surface Additional contributing sources include surface adhesion and relative micro-sliding between the surfaces of contact. It depends very much on the material of the wheel or tire and the sort of ground. In this experiment, the movement of Handicapped Walker With Remote Control is testing on the mosaic. This walker has two wheels and two castors which the material of Handicapped Walker With Remote Control wheel and castor is made of rubbers. Below shown a human control the motion of the Handicapped Walker With Remote Control in manually the picture after that are shown the motion of the Handicapped Walker With Remote Control is control by remote control on the smooth and rugged surface which the  motion of Handicapped Walker With Remote Control is testing in linear condition. From the observation, when contacting surfaces move relative to each other, the friction between the two surfaces converts kinetic energy into thermal energy, or heat and the Handicapped Walker With Remote Control can move in normal condition and wheels and castors of the Handicapped Walker With Remote Control is not spin on the mosaic.

   

 Rugged surface

 Smooth surface

EXPERIMENT 2: Hilly road (uphill)

This experiment is to determine the ability the Handicapped Walker With Remote Control move on hilly road. Generally, if we consider the rotation as being about the center of mass of the object, then the frictional force must be in a direction to provide the torque necessary to decrease or increase the angular velocity, depending on whether the object is accelerating or decelerating, respectively.  Note that the friction can be in the direction of motion (rolling downhill) or opposite to it (rolling uphill). In this experiment, to testing the ability of Handicapped Walker With Remote Control, a human press the switch to climb the hill (uphill).From the observation, the Handicapped Walker With Remote Control has ability to uphill which it can move in stable condition. Figure 5.7 are shown the result of this experiment.