Project Complete - PM's Review

The project is now completed with the final test concluded, as depicted by the Gantt chart below.



The project started off very well, and in the initial phases we accelerated beyond schedule. Unfortunately this progress was lost over the Easter holiday's, though we pulled the project back and completed it on time. In retrospect I should have accounted more for the inevitable decrease in group members output over the holidays and planned around them, though by motivating my team immediately as term resumed we were able to finish on time to a high standard.

The intended budget for this project was £0.00 which we were able to meet. All components were sourced for free as either unneeded spares or from recycling centres over the Easter holiday's.

The program worked well and much of the design was also good, though we were let down by the rear caster wheel. The original was sourced by me from Swindon Recycling Centre, and when tested it turned out to be to heavy and stiff. I made attempts to modify the wheel and also treated it with WD40 to loosen it, though the weight ultimately let it down. The wheel was replaced last minute with a homemade caster wheel which did not perform well on the line following mode as it would cause the buggy to veer off course whenever it tried to turn. If I were to do this project again, I would have sourced a light-weight pololu ball caster to replace this wheel.

The symbol reading part of the final test went smoothly, as the rear wheel did not have a chance to cause problems. The design assessment was acceptable, though the aesthetics of the design could have been improved with practise. Some of my cuts were not perfectly straight and the holes drilled by Anand caused the acrylic plates to crack in several places. This caused the final build to look a little rushed, and were a result of our limited experience using tools.

The power of the motors was also a little low. The battery pack was only just powerful enough to power the circuit and motors. As seen in other groups, if I were to repeat this project I would have designed a secondary power supply specifically for the motors.

In conclusion I feel this project went well. We scored highly in the final assessment and worked well as a team. To improve our project if I were to do it again I would have planned our schedule better around the Easter holiday's so that we could have had more time testing, installed a secondary power source for the motors, dedicated more time to ensuring the build was neat, and sourced a better rear caster wheel.

Final Build

I sourced the acrylic for the final build from a scrap bin at the university; and with the assistance of the Assistant PM, Electronics Specialist, and Chief Designer; began the build process.

The first stage was to measure the components, create a design, and to cut the acrylic to size. Sophie and I did the first stage of this, and then Sophie created the robot design shown below. I was then able to cut the boards to size.


Picture Taken By Sophie Latham

Sophie then, with advice from the team, used the component sizes to mark out where all holes that required drilling should be positioned and the boards were given to Anand, in the condition shown in the picture below, for him to drill at home.


Picture Taken By Sophie Latham

The next stage was for me to cut out the slots for the robots arms and legs from the top piece, whilst Anand wired in the circuit to the lower piece of acrylic. Once this was complete, Daljinder sanded down the acrylic components and I designed a variable spacer to be placed between the sensor array circuit and the lower sheet of acrylic. This design is depicted below and as the bolts shown are tightened/loosened, the array is raise/lowered respectively. This design keeps the circuit under enough tension to keep it in place without risking damage. There was concern raised about the heat from the circuit melting the sponge, though these were quickly dismissed considering the low voltage and frequency at which the circuits operated.


Picture Taken By Sophie Latham and Edited By Mark Hawkins

The result of these processes is shown below.


Picture Taken By Sophie Latham

Sophie then, with some advice from me, finished her design by using my electrical tape, and part of a disco ball, to decorate the face plate on the top of our robot. This was then bolted down and the final assembly was complete, as depicted in the images below.


Picture Taken By Sophie Latham


Picture Taken By Anand Bhana

The caster wheel on the back of this final design turned out not to be fit for purpose. It was too heavy and caused the batteries to drain too quickly with little movement.

After much debate amongst the team, Sandra's design for a new back wheel was chosen and implemented, creating the final design shown below that was used in the final test.


Picture Taken By Sandra Donohoe

Final Program

The chief programmer presented the initial final program to the group the day before the final test, though on occasion the buggy would stop when it lost the posistion of the track. As a result the project manager suggested a feed back reversing system whenever the central track relation sensor recorded a white background. This was then installed to produce the final program, which was then calibrated by the programmer.

The following is the final program:

Meeting 7 (26/04/2010)

At this point the lead programmer confirmed she had completed the program testing to a satisfactory standard having taken timer advice from me, with just final calibration experiments necessary. The buggy chassis had been marked out to design; drilled; and cut to shape by the build team, and the final assembly had been completed.

The final test in this meeting however proved the caster wheel at the rear of the buggy caused an unacceptable level of drag due to its weight and off centre pivot. This will require redesigning tomorrow morning before the assessed test, in order to maximise the operational ability of the buggy.

The electronics specialist and assistant project manager have the majority of the images and videos of the construction phase for this project. These shall be posted shortly, along with a detailed explanation of the design and assembly process.

After the test, all group members shall post retrospective reports about this project, including how successful they believed it to be and what future changes they would make to improve the buggy if they were to do it again.

Project Update (26/04/2010)

The following Gantt chart shows the project progress to date. The circuit has been completed, and the program has been successfully tested (though will require calibration in the morning before the assessed test).


The build has been completed and successfully tested, though the rear caster wheel was discovered to cause drag which resulted in the buggy veering off course. It was decided to test an alternative wheel design which was also successfully tested and, in the morning once new batteries have been sourced, the best design will be neatly installed. The progress of the buggy has extended fully into the project buffer, though is due to be completed on schedule.

Meeting 6 (21/04/2010)

The final design was discussed and finalised. Build and program test schedule has been set and is due to be completed by Friday 23/04/2010.

Circuit build

Anand and I sourced a length of ribbon wire and arranged the circuit components as shown below.


The circuit was soldered using a colour code system for the wires, which should make the assembly easier. The image below depicts the completed circuit.

The dimensions of this circiut are 81x37x20mm with the LED's and sensors 5mm from the edge of the board and 20mm separation. The dimensions of the motor board and PicAxe board are 37x35x15mm and 62x51x15mm respectively.

Wheels and Chassis Material

I have sourced the wheels and chassis material as dipicted below.



The wheels are castor wheels which are free to rotate about the virtical axis. These wheels will help support the buggy. They are assembled as shown below.



All designs will incorporate these components.

Initial Buggy Design

This is my initial design for the buggy chassis, without the circuit or drive wheels attached. The circuit would be mounted in between the top and base, and the drive wheels would be mounted in the location highlighted on the engineering drawing.

Firstly, here are CAD images of the buggy from two angles.




And here is a CAD engineering drawing of this initial design from multiple angles

LED mounting

The LED's must be mounted at the front of the buggy, close to the LDR sensors. The following images show the type of arrangement needed for the sensor board to be effective.





http://www.micahcarrick.com/05-27-2006/failurebot-line-following-robot.html

This design would work well under normal conditions, however since the LED and sensor array is not well shielded, the buggy may loss its ability to distinguish between light and dark regions in more extreme ambient light situations.

The solution to this is to introduce shielding to direct the light from the LED's towards a small spot on the ground. The following example shows this principle at work.



http://www.wa4dsy.net/robot/polyathlon-robot/polymax-improvements

This will significantly increase the efficiency of the buggy and the range of ambient light conditions in which it can operate. Below is a rough CAD image of the LED encased in a drinking straw to help direct light to a small area of ground underneath the buggy.



The LDR's will also have to be shielded in a similar fashion.

Project Update (10/04/2010)

Project Progress
The project has slipped behind slightly over the Easter holidays, however it is not yet time to start considering an action plan. The Gantt chart below shows the buggy progress to be one day behind.


The components have all been sourced and so the final tasks required include circuit and buggy assembly. The design of the buggy will be finalised during this construct phase.

Assignments

Mark Hawkins: Direct Assembly of Circuit and Buggy

Sophie Latham: Oversee Buggy Assembly and Assist Construction as Required

Sandra Donohoe: Test Program on Buggy and Assist Construction as Required

Anand Bhana: Solder Circuit and Test

Daljinder Sandhu: Finalise Design and Construct Buggy

All Members: Continue Posting and Begin Work on Personal Page Sections of the Blog

Initial Design Research

The first stage of research was to look at some other robot designs on the Internet. The first was a line following buggy whose chassis was made from a sandwich box. This robot is shown and referenced below.


www.arrickrobotics.com/robomenu/sandwich.html

This robot seemed simple and easy to make. The advantages of a robot such as this would be that the box could be opened easily for maintenance, and that it could be easily decorated. The box I decided to consider if we were to choose a design such as this was an ice-cream tub of the approximate type shown below.



With farther thought however, this design did not seem challenging enough and so I continued researching robot designs. The next potential design considered was a stacked layer robot such as the two below.




www.robotroom.com/Repairs.html

I did consider using a construction toy such as Lego or Meccano, though this seemed too simple for the purposes of this project. The most impressive design I found was of a robot made from multiple plastic components bolted together. The particular robot shown below is the Microbric Viper, though we would of course design our own.




www.microbric.com/page.php?sId=19

The design I will be focusing on will be made from multiple plastic sections. The sections will be cut to fit and stacked, with the circuits and other components sandwiched in layers. I believe this will create the most impressive robot, though it may be impractically complex to build. This design will have two caster wheels, one at the front and one at the back, and will have its drive wheels on the sides in the middle of the robot. Concept drawings of this design will be posted here soon.

Project Update (23/03/2010)

The project is ahead of schedule thus far. The Gantt chart below shows the course of the project and that as long as we continue to work effectively, the five day project buffer will not be required.



All research is complete, as well as the designs and program. The prototypes were successfully tested today and plans for the final build of the circuit and buggy were finalised. The circuit components have been sourced and tested, however several buggy components still require sourcing.

In summary, we are ahead of schedule and the tasks remaining involve sourcing the last buggy components, soldering the circuit, and assembling the buggy.

Posted by Mark Hawkins

Meeting 5 (23/03/2010)

This meeting was held in the lab and during this time the PICAXE program was finalised and tested. The circuit was built and tested utilising a breadboard.

Members discussed the construction of the buggy and the build team completed the final design.

For the next meeting members are required to source remaining materials and solder the strip board. Members will also post all relevant material to the blog, including design research, final designs, component lists, and explanation of the rational behind these choices.

Program Ideas

Here is the first experimental code written for this project
___________________________________________________

'For the mode toggle switch
main:

if pin7 = 1 then 'when pin7 is high
if b0 = 0 then 'if bo is low then...
b0 = 1 'make it high

else
b0 = 0 'otherwise make it low

endif
endif

pause 100 'pause to account for human reactions when pressing the switch

'Sensor Encoding
main1:
readadc 1, b1 'Sensor LEFT to b1
readadc 2, b2 'Sensor MIDDLE to b2
readadc 3, b3 'Sensor RIGHT to b3

'Line follow mode

if b0 = 0 then 'Move forward initially
high 1
low 2
high 3
low 4

do while b1 > 20 'Calibrate - turn RIGHT when right sensor activated
high 1
low 2
low 3
high 4
goto main1
loop

do while b3 > 20 'Calibrate - turn LEFT when right sensor activated
low 1
high 2
high 3
low 4
goto main1
loop

endif

'Symbol read mode

if b0 = 1 then 'Move forward initially
high 1
low 2
high 3
low 4

'Move Forward RIGHT Forward
if b1 > 20 then 'Calibrate
high 1
low 2
high 3
low 4
pause 1000

low 1
high 2
high 3
low 4
pause 300 'Calibrate

high 1
low 2
high 3
low 4
pause 1000

endif

'Move Forward STOP Backwards
if b2 > 20 then 'Calibrate
high 1
low 2
high 3
low 4
pause 1000

low 1
low 2
low 3
low 4
pause 1000

low 1
high 2
low 3
high 4
pause 1000

endif

'Move Forward LEFT Forward
if b3 > 20 then 'Calibrate

high 1
low 2
high 3
low 4
pause 1000

high 1
low 2
low 3
high 4
pause 300 'Calibrate

low 2
high 3
low 4
pause 1000

endif
endif

goto main
___________________________________________________

Posted by Mark Hawkins

Robots in Industry

Industrial Applications of Robots

Robots may be used for many tasks in industry. The most common types of robot that resemble this project are robotic arms, with tools attached which are designed to preform specific tasks with great precision. these could be soldering, welding, painting, assembly, or one of many other such applications. They use software similar to the line following buggy from this project to maintain track of their position in relation to their environment.

Robots can be made much faster, stronger, and more precise than humans could ever be, though they also have several key drawbacks which will be discussed in the next section.


http://www.robots.com/faq.php?question=robot+industrial

Morality of Entirely Autonomous Robots

Entirely autonomous robots present a series of advantages and disadvantages. The main advantages are that robots are cheaper, faster, stronger, and more precise than their human equivalents. They can greatly increase a factory's output with a single large initial cost, and then relatively little cost in maintenance compared to human wages until they eventually require upgrading or replacing.

The greatest problem in the immediacy is simply that increased automation in the industrial environment decreases the need for human employees, leading to jobs being lost and leaving skilled manual labourers with no choice but to retrain and their trade skills to be lost in time.

The next problem is that robots lack intuition and human common sense. If a robot detects a problem that it has never encountered before, or if its timing or position is lost by its memory, then the robots actions may become unpredictable. Robots are much stronger than humans and as a result can cause comparatively massive amounts of damage when malfunctioning.

The last of the significant problems with autonomous robots is the issue of emergence. When any system grows to sufficient complexity, emergent behaviours begin to form. As repetitive tasks are preformed, and complex codes are iterated through the robots memory, seemingly random segments of code can eventually begin to interact and interfere with one another resulting in the formation of behavioral patterns which resemble consciousness and personality. In reality most of these emergent behaviours are too unstable to be call either, and simply cause the robot to malfunction, however as systems become more powerful the debate over the problems of emergence will undoubtedly grow far louder.

http://www.sciencedaily.com/releases/2007/02/070222155713.htm
http://gral.ip.rm.cnr.it/rcalabretta/calabretta.modul2.pdf

Posted by Mark Hawkins

Meeting 3 (16/03/2010)

Basic control program was created and the motor side of the circuit was built. Tasks for the next meeting were set, which included research into industry applications and whether or not too much automation was a good thing.

In the meeting it was decided to use LDR sensors combined with LED backing light. This was because the form A reed switches were dicovered as not being sensitive enough to detect the small field created by the magnetic path.

Next meeting thursday

Meeting 2 (15/03/2010)

Basics designs and program possibilities were discussed and roles were formally assigned.

Assignment of roles
- Project Manager (Programming team): Mark Hawkins
- Assistant Project Manager (Build Team): Sophie Latham
- Lead Programmer: Sandra Donohoe
- Electronics Specialist: Anand Bhana
- Chief Designer: Daljinder Sandhu

By the next meeting member will have completed their individual research and will bring it to the meeting tomorrow.