design brief - intranet.cesc.vic.edu.au creative... · design brief the client, ... materials...

Jason Vekas 12F ∙ Lyndale Secondary College ∙ 2009

Design Brief

The client, Mr. Vaughn Anderson, the Technology Coordinator at Lyndale Secondary College,

has requested the design and construction a motor vehicle or other device which can be

programmed using PICAXE technology. He wants to use this device to help teach students in

his year 9 and 10 programming classes how to write in the BASIC programming language. He

believes that having a real world application for the program scripts will make the class

more interesting for his students.

The client has left various specifications for the design of this unit. He has stated that the

vehicle must cost no more than $80 per unit, and that it must be no larger than the size of

an A4 sheet of paper (approximately 20cm x 30cm). He has also requested that, if possible,

the unit be controlled by an infrared remote control, as this will further engage his students.

If this is not possible, the device must be able to run forward and, on contact with a wall or

other item, be able to reverse and turn in order to manoeuvre around the object. The PCB

used in the unit must be enclosed so that there are no exposed wires or components, but at

the same time, must be accessible via an access panel, so as to allow for repairs. The

batteries must also be accessible so that they are able to be replaced easily. The only visible

components may be the stereo socket, to allow for the programming of the PICAXE chip, or

any other necessary components such as infrared sensors or switches.

Although not directly specified, the device should be visually appealing, so a shell to enclose

the vehicle should also be designed and produced. Not only will this make the buggy visually

appealing, but it will help to meet the client’s specification that there should be no visible

unnecessary components. The shell and device should also be durable enough to withstand

prolonged use.

As the device will only be used during class time, it will need to be able to operate in a

computer class room environment. Therefore, it must be capable of operating on carpet,

table tops and possibly tiles. It should also move at a reasonable, slower speed, as it is not

going to be used in an open or outdoor environment.

After taking the above specifications into account, I have decided to design and construct a

buggy which can be programmed to operate via either an infrared remote control, or

switches mounted on the front of buggy. This way, the client can use it as a reversible buggy

is desired. By making use of a PICAXE-14M chip, it will be possible for the buggy to be

programmed using the BASIC programming language as specified.

The base of the buggy will be made from a commercial track and wheel set and gearbox

from Tamiya, whereas the shell to enclose the PCB and batteries will be designed and

constructed from aluminium.


Considerations

Function:

As the system is a remote controlled toy car, its function is to respond to an infrared input

device and move in the direction stipulated by the PICAXE program. The system can be

programmed via USB port and its responses to the infrared device are editable. This is to

allow the actions undertaken after an input to be altered by the user, thus making the

operation of the system more flexible.

The overall function of the system, however, is to convert chemical energy from the

batteries, into rotational and linear motion. This is achieved by the system’s gearbox,

motors and wheels.

Purpose:

The purpose of the overall system is to help teach IT students the BASIC programming

language. The system can be used by IT teachers as a real world example of how

programming is used in everyday life. The students can write their own programs then

download it to the buggy to see how it works in real life, instead of using on screen

simulators. Having a real world application for the programs will engage students as well as

help to further their understanding of software development and information technology.

The purpose of the systems circuitry is to receive an infrared signal, then process it

accordingly. The effect of this is generally to move the buggy in a desired direction with the

use of the motors and wheels attached to the circuit.

Materials:

The materials used to construct the shell of the buggy need to be strong and durable

enough to withstand prolonged use. However, the materials used cannot be too heavy, as

this may affect the operation of the vehicle.

Safety:

During construction of the product, many different tools and other equipment will be used.

Some of these may cause harm to the user, if not used carefully. A risk assessment criteria

sheet will need to be constructed and adhered to throughout the process of constructing

this device.


Australian Standards

AS/NZS 4360:2004

These are the Australian Standards on risk management. They outline the process for

identifying, analysing, evaluating and treating, any risks associated with the construction of

this, or any other device. The Risk Management Guidelines AS/NZS 4360:2004 Booklet can

be purchased from www.riskmanagement.com.au for more detailed information on risk

management in Australian workplaces.

AS/NZS 3000:2007

These are the Australian Standards for Wiring Rules. These rules and guidelines are mostly for

electricians, but some may be applicable to this project. These guidelines can be purchased online

from www.wiringrules.standards.org.au

Constraints

Cost:

The client has requested that the overall cost of the product not exceed $80, this is so that

he can afford to purchase 12 of these units for his programming class.

Size:

The requested size is no larger than 20cm x 30cm, approximately the size of an A4 sheet of

paper. This is to allow a class set of units to be carried in a single crate.

Time:

There is an approximate time limit of 35 weeks from the time of receiving the client’s letter

to the due date of the project.

Available tools and equipment include:

Soldering iron, drill press, hot glue gun, computer, milling machine, metal lathes, plastic

heater, and a sheet metal bending brake.

Materials available for the production of the PCB include:

Blank printed circuit boards, solder, insulated copper wire, heat shrink, mixed components,

various types of switches, breadboards, and serial cables for programming the PICAXE chip.

Materials available for building the buggy’s shell include:

Sheets of aluminium, coloured plastic, wheels, motors, gear boxes, track and wheel sets,

glue, hinges, screws, batteries and battery housing.

RISK ASSESSMENT MATRIX Determining the Level of Risk

Health & Safety Services July 2009

1

This document can be used to identify the level of risk and help to prioritise any control measures.

Consider the consequences and likelihood for each of the identified hazards and use the table to obtain the risk level.

Consequences

1 – Insignificant Dealt with by in-house first

aid, etc

2 – Minor Medical help needed. Treatment by medical professional/hospital

outpatient, etc

3 – Moderate Significant non-permanent

injury. Overnight hospitalisation

(inpatient)

4 – Major Extensive permanent injury

(eg loss of finger/s) Extended hospitalisation

5 – Catastrophic Death.

Permanent disabling injury (eg blindness, loss of hand/s,

quadriplegia)

Lik

eli

ho

od

A - Almost certain to occur in most circumstances High (H) High (H) Extreme (X) Extreme (X) Extreme (X)

B - Likely to occur frequently Moderate (M) High (H) High (H) Extreme (X) Extreme (X)

C - Possible and likely to occur at some time Low (L) Moderate(M) High (H) Extreme (X) Extreme (X)

D - Unlikely to occur but could happen Low (L) Low (L) Moderate(M) High (H) Extreme (X)

E - May occur but only in rare and exceptional circumstances Low (L) Low (L) Moderate (M) High (H) High (H)

How to Prioritise the Risk Rating Once the level of risk has been determined the following table may be of use in determining when to act to institute the control measures.

Extreme Act immediately to mitigate the risk.Either eliminate, substitute or implement engineering control measures. Remove the hazard at the source. An identified extreme risk does not allow scope for the use of administrative controls or PPE , even in the short term.

High Act immediately to mitigate the risk. Either eliminate, substitute or implement engineering control measures.

If these controls are not immediately accessible, set a timeframe for their implementation and establish interim risk reduction strategies for the period of the set timeframe.

An achievable timeframe must be established to ensure that elimination, substitution or engineering controls are implemented.

NOTE: Risk (and not cost) must be the primary consideration in determining the timeframe. A timeframe of greater than 6 months would generally not be acceptable for any hazard identified as high risk.

Medium Take reasonable steps to mitigate the risk. Until elimination, substitution or engineering controls can be implemented, institute administrative or personal protective equipment controls. These “lower level” controls must not be considered permanent solutions. The time for which they are established must be based on risk. At the end of the time, if the risk has not been addressed by elimination, substitution or engineering controls a further risk assessment must be undertaken.

Interim measures until permanent solutions can be implemented:

Develop administrative controls to limit the use or access.

Provide supervision and specific training related to the issue of concern. (See Administrative Controls below)

Low Take reasonable steps to mitigate and monitor the risk. Institute permanent controls in the long term. Permanent

controls may be administrative in nature if the hazard has low frequency, rare likelihood and insignificant consequence.

Hierarchy of Control Controls identified may be a mixture of the hierarchy in order to provide minimum operator exposure.

Elimination Eliminate the hazard.

Substitution Provide an alternative that is capable of performing the same task and is safer to use.

Engineering Controls Provide or construct a physical barrier or guard.

Administrative Controls Develop policies, procedures practices and guidelines, in consultation with employees, to mitigate the risk. Provide training, instruction and supervision about the hazard.

Personal Protective Equipment Personal equipment designed to protect the individual from the hazard.

RISK ASSESSMENT SUMMARY

Topic: Date: Issue No. Review date:

Identify Hazards and subsequent Risks

Analyse Risks

Evaluate Risks

Identify and evaluate existing risk controls Further Risk Treatments

Hazards/Issues/Risks Consequence Likelihood Risk level

What we are doing now to manage this risk. Effectiveness of our strategies

New risk level

Further action needed

Opportunities for improvement

Health & Safety Services July 2009

2

Burns from soldering iron

2

C

M

Use soldering iron stand Mostly

Effective

L Wear safety gloves when working with soldering iron

Solder in eye

5

D

X

Wear safety glasses Entirely Effective

L

–

Inhalation of fumes from solder

1

B

M Use solder only in well ventilated areas

Entirely Effective

L

–

Electrical shock

3

E

M Check all power cords to assure there are no splits in the plastic

Mostly Effective

L

–

Dropping tools on feet

1

C

L Keep tools away from table edge

Partially Effective

L

Wear protective shoes

Cut by sharp objects such as saws

2

C

M Take care when using sharp objects

Partially Effective

L Wear safety gloves when using sharp objects

Hair/clothing caught in drill press

4

D

H Tie long hair back, remove hanging clothes, eg. ties

Mostly Effective

L

–


Research

and

Annotations


4 Wheeled Designs

Criteria High Medium Low

Appearance •

Suitable for classroom use •

Enclosed circuit •

Repairable •

Infrared •

Materials available •

Ease of manufacture •

While this design looks interesting, it has too many visible wires, components and circuitry and it does

not make use of infrared technology.


Appearance •



Repairable •

Infrared •



While this design looks nice and simple and easy to make, its circuitry is entirely visible. This does not

meet the client’s specifications.


Appearance •



Repairable •

Infrared •



This design uses the base of a commercial remote control car. This is a good idea and would be easy to

manufacture, however it would be expensive to purchase the base, and it may operate at a speed too

fast for a classroom environment.

1

2

3


2-3 Wheeled Designs


Appearance •



Repairable •

Infrared •



This design may meet some of the specifications, however, the circuit is not covered and the materials

to make it are not readily available.


Appearance •



Repairable •

Infrared •



This design scored very low on the criteria, and, as such, would not be a suitable choice for this project.


Appearance •



Repairable •

Infrared •



The small plastic wheels and low standing if this design would not allow it to run properly on carpet. Meaning it does not meet the client’s specifications.

4

5

6



Appearance •



Repairable •

Infrared •



I really like the idea of constructing the shell out of Lego pieces, however, these pieces are not readily

available. Also, this design would not be very durable


Appearance •



Repairable •

Infrared •



This design looks interesting, however, the fact that its shell is made of the circuitry, means it does not

meet the clients specifications of having an enclosed circuit and components.


Appearance •



Repairable •

Infrared •



This design doesn’t look too appealing, nor does it use infrared technology. Also, its circuit is not

enclosed, making it a bad choice for this project.

7

8

9


Track Wheeled Designs


Appearance •



Repairable •

Infrared •



This design is very suitable for classroom use, however it is not very durable and the circuitry is

entirely exposed.


Appearance •



Repairable •

Infrared •



This design is nice and simple, however, its circuitry is not enclosed.


Appearance •



Repairable •

Infrared •



The circuit of this design sits on top of the buggy. This does not meet the client’s specifications of

having an enclosed circuit and components.

10

11

12



Appearance •



Repairable •

Infrared •



This design has too many exposed wires and components to be considered for this project.


Appearance •



Repairable •

Infrared •



This design would be a good choice for this project if the circuit and batteries were enclosed.


Appearance •



Repairable •

Infrared •



I like this design, however, its shell is not be easily removable. This means that it will be hard to repair

any faulty components.

13

14

15


Conclusion

While I like the look of some of these designs, I have decided that I will create my own shell design.

Using some of these designs as inspiration, I will design a shell and circuit myself. One of the ideas I

will incorporate into my system is the tracked wheel platform. I will use the design from image 11 as

the base for my system, but will create a shell to enclose it, along with the circuit and batteries, so as

to make it more appealing.

Sources

1 http://www.syzygytech.com/2008/11/15/infrared-robot-detection-with-obstacle-avoidance/

2 http://letsmakerobots.com/node/798

3 http://www.dharmanitech.com/2009/01/ir-remote-controlled-car-pwm-motor.html


5 http://www.active-robots.com/products/robots/robo-jr.shtml

6 http://electronics.saintjohn.nbcc.nb.ca/sumo/sumo.htm

7 http://www.techno-stuff.com/DIRPD-T.htm

8 http://www.microbric.com/page.php?sId=17

9 http://robotechno.us/line-follower-robot-tutorial.html



12 http://www.robotshop.ca/inex-interactive-c-robot-kit-3.html

13 http://nathanbrinks.com/projects/tankesc/tankesc_phase1.php

14 http://luckylarry.co.uk/2009/08/obstacle-avoidance-robot-build-your-own-larrybot/



Product

Evaluation


Selection Criteria

□ Can the device be programmed using PICAXE technology?

□ Does the device use the BASIC programming language?

□ Does the device cost less than $80 per unit?

□ Is the device smaller than 20cm x 30cm?

□ Can the device be controlled via an infrared remote control?

□ Is the device capable of operating on carpet and table tops?

□ Does the device move at a reasonable, slower speed?

□ Are the PCB, wires, and other components enclosed?

□ Is the PCB accessible for repairs?

□ Are the batteries accessible for changing?

□ Is the device durable enough to withstand prolonged use?

design brief - intranet.cesc.vic.edu.au creative... · design brief the client, ... materials...

Documents