5. Functions of robots

1. What is meant by 'Degrees of freedom'? Ensure you include a diagram to highlight your understanding. (p. 253)

Robots are designed to carry out movement. The amount of movement is ­­–determined by the degrees of freedom built into the design. Degrees of freedom are the number of different ways an attachment can pivot. A human has seven degrees of freedom as it is able to rotate in seven different ways.

NOTE: No robot, or computer program will function unless it has some form of input and/or output to display the processed data.There are many ways of inputting and outputting data into a robotic system

2. There are 5 general input devices used in robotics. List them below. (p. 254)

1. Digital Camera
2. Keyboard
3. Light Pen
4. Mouse
5. Microphone

3. Sensors are a common input device on robotics. Complete the following table (see p. 254 to 255)

Sensor Name	Description	Examples of use	Potential Issues
Thermostat	Switch that opens at a set temperature and stays open while the temperature remains at the level or higher.	Ovens, hot-water system	Not as accurate or as quick to respond as other sensors but they are cheap.
Thermistor	Measures temperature continually as resistance: when the temperature increases, resistance drops	Microwave ovens, air conditioners	Similar to thermostat and also cheap.
Semiconductor	Are sensor materials with electrical properties that are not as good as those of good electrical conductors such as copper wire but not as poor as non-electrical conductors.	Silicon base	Not great   conductors, but not poor either
Light	Light sensors detect changes in the level of light.	Driveway lights	Not very durable
Position	A position sensor would be a simple contact sensor a switch that could be ether turned on or off	Light switch	Can be unreliable
Potentiometers	Used to determine rotation. They work on electrical resistance and the meter shows the amount of voltage at a particular point.	Used in robotics	Only gives a fairly accurate reading - not as accurate as other types of sensors
Sonar	Uses sound to determine position of objects, by bouncing sound waves off objects.	Submarines use sonar to see other boats on the water.	Not as accurate as other types of sensors

4. Define and compare an Actuator to a Sensor

Actuator: An actuator does the work of a system but doesn't actually obtain that information

Sensor: A sensor collects data from the environment through the use of sensor mediums.

Sensors take the information from and environment so that the actuators carry out action using the information provided.

5. Actuators are a common output device on robotics. Complete the following table (see p. 256)

.

Output devices	Description and main feature	Advantage	Disadvantage
Speakers	Speakers volume control; available to a wide range of people.	Normal speech rather than synthesised speech is available	Requires extra hardware like a sound card
Display (CRT or LCD)	Available for many applications	no waste of paper; can be interactive	No hard copy
Solenoids (an actuator)	Use an electromagnet to move an arm or plunger through a small movement.	Easily pushes and pulls and objects	Requires extra hardware for operation. Electric currents may prove to be harmful.
Stepping motors (an actuator)	Uses electromagnets to measure rotations of a motor around the spindle to measure its position.	Gives good accurate measurements of the rotations of wheels etc..	Not durable and can often contribute to noise pollution
Position	Can be a simple contact sensor like a switch or can be more complex in which it could calculate how far an object is from it.	Offers optimal performance for operating arms and their degrees of movement	Can very buggy and takes a while to program it for optimal performance
Potentiometers	Used to determine rotation by harnessing electrical resistance and shows the voltage at a certain point	Very good at measuring rotations to a high standard	Not as accurate readings as other sensors but still quite good
Sonar	Uses sound to determine position by using high frequencies which bounce off objects	Can be used to locate objects from great distances	Changes in the environment, such as temperature, pressure, humidity, air turbulence and airborne particles affect response.

6. Define Primary Storage and provides examples (p. 257)

Primary storage, which is found on the motherboard and holds data for processing, processed data waiting to be outputted and instructions for processing. It also acts as a link between computers and their secondary permanent storage. Primary storage is needed so that tasks/ instructions can be carried out efficiently. Can be either permanent, ROM, or temporary, RAM. A computer cache is an example of primary storage.

7. Define Secondary Storage and provide examples

Secondary storage is anything that is not part of the CPU. The size of your secondary storage is determines the ability of the system to store information for future use. An example of secondary storage would be a hard drive or DVD.

8. Using the following diagram, write below what each letter represents. You will find an overview of this motherboard at http://www.build-your-own-computer.net/motherboard-diagram.html

A:PCI Slot

B:PCI-E 16x Slot

C:PCI-E 1x Slot

D:Northbridge

E:ATX 12V 2X and 4 Pin Power Connection

F:CPU-Fan

G:Socket

H:Memory Slots

I:ATX Power Connector

J:IDE Connection

K:Southbridge

L:SATA Connections

M:Front Panel Connections

N:FDD Connection

O:External USB Connections

P:CMOS battery