DESIGN OF REMOTE CONTROLLED LIFE SAVING BUOY AT MUHIMBILI HOSPITAL

PROBLEM STATEMENT

In any water accident one of the major rescue processes is by using lifesaving buoy. A problem arise when a rescuer tries to throw a buoy to a victim, the buoy may not reach the desired target and might be caused of a bad weather or a victim distance from the rescuer which makes lifesaving procedure impossible or take a long time. Also the rescuer is required to hold a rope very tight when throwing for targeting and pulling the victim.

OBJECTIVES

MAIN OBJECTIVES

To develop a lifesaving buoy system which consist of lifesaving bouy part and remote controlled part.

SPECIFIC OBJECTIVES

• To analyze the existing lifesaving buoy.
• To design a proposed remote-controlled circuit.
• To simulate the controlled circuit designed.
• To build and implement prototype of a proposed system.

SIGNIFICANCES OF THE PROJECT

• Proposed system will make the rescue process easier.
• It will decrease number of death due to water accident.

Maximum weight of hauling

This determines maximum weight that a lifesaving buoy can withstand without sink. From a Buoyance law (Law of floatation), an object whose weight exceed its buoyancy (up thrust) tend to sink.

       Real weight = Apparent weight + Upthrust 

But, apparent weight = 0 

Real weight = Upthrust = Buoyant force (𝐹_𝐵)

  𝐹_𝐵 = Vρg           But  𝐹_𝐵 = mg

mg = Vρg            

Hence, m = Vρ

m = mass of the object 

V = volume of the object

Ρ = density of the water = 1027kg/𝑚^3

For a standard remote-controlled lifesaving buoy it has dimension of (1000*800*250) mm but lifesaving buoy is in cylindrical shape.

Volume of a cylindrical shape  = π𝑟^2 ℎ

V =  π*〖(0.5)〗^2 *0.25 = 0.1963𝑚^3

m = 0.1963*1027 = 201.65kg      

So the maximum weight of hauling is 200kg 

Size of the motor 

For production it is preferable to use motor that has running time of 30 mins means (travel at continuous speed). The motor has maximum speed of 15km/h (4.16m/s) unloaded. When loaded it will have a maximum of 2m/s

In order to find the size of the motor, we must know the appropriate size of the motor that is capable to run the propeller at a speed of 2m/s when loaded.

Power = 𝑊𝑜𝑟𝑘/𝑡𝑖𝑚𝑒 (J) = 𝐸𝑛𝑒𝑟𝑔𝑦/𝑡𝑖𝑚𝑒

Energy used is Kinetic energy since the remote-controlled lifesaving buoy is moving.

KE = 1/2 m𝑣^2

Velocity = 2m/s (loaded)

Mass = 200kg

KE = 0.5*200*(2^2)

KE = 400J

Power = 400𝐽/1𝑠

Power = 400W

Hence size of a brushless dc motor with a power of 400W can be found from research specifications.

Size of the battery

The proper size of battery should be chosen for a better performance. The battery should give the maximum voltage of 24V. From the specification of the battery having output of 24V/32Ah

Proposed circuit of the project