After completion of my project (see DT009 final year project) it was submitted in to the Engineers Ireland innovative engineering student of the year (ISOY) award competition also referred to as the Siemens prize.
The first stage was submission of a 500 word essay about your project from which a judging panel selected the finalists from all over the country. the final 6 including myself were then required to submit a 2,500 word essay, take part in a 30 min presentation/interview with a judging panel of 6 CEOs and entrepreneurs including a representative from Siemens, then lastly present our projects to a general audience of which the judging panel sat in on and graded.
Footage from my finalist presentation
I was the only student from an electrical and electronic background and one of 2 level 7 (ordinary degree) students, The rest of the competitors consisted of level 8 (Honors degrees) and level 9 ( Masters degree) students. The work entered was very competitive and the standards astronomically high which made for a very interesting day. The other projects were Haelios Solar Technologies™ – Solar Updraft Tower Development, Design and build of a Human-Powered Washing Machine, Construction Sector Safety Hook Design and Development, The design and development of a under-actuated, compliant anthropomorphic hand capable of dexterous grasping for a Service Robot with the winning project being an Automatically fed post driver
Some photos taken from the presentation and awards ceremony on 10th of June in Engineers Ireland HQ, Clyde Rd
Unfortunately I was not the best on the day, but it was an immensely valuable experience. Provided me with great exposure and networking opportunities and hopefully I’ll be returning in time to come with either another project to compete or as an engineer seeking charter-ship.
The end of May ’16 saw the completion of my final year project entitled “Actuation and Control of a Trans-Radial Upper Limb Prosthesis”
The project successfully attained a grade of 84% which combined with my other marks granted unto me my BEngTech in Electrical and Control Systems graduating with a Merit, upper class (2.1).
The project still has some slight alterations necessary, mainly in the mechanical operation, this is due to my lack of knowledge in the area and as a result not foreseeing some of the problems encountered. The code however worked flawlessly and the circuitry required minute alterations.
Below you can see a slide show of the fully assembled project.
After wiring up the entire measurement circuit I began testing it.
I started out with belling the home made probes to ensure they were still of high quality and measuring the battery pack supply which was 5.8V DC the reference voltage however measured in at 0.54V DC which is about half of our desired reference it was then I realised I had neglected to connect the 5V supply to the LM324n chip. When I had done so the Vref rose to 1.92 V DC when the circuit was re-energised.
For the initial testing I separated the circuit into its key components, I tested the output from the InAmp, the OpAmp and lastly the output from the comparator .I used both a standard multi-meter and a low voltage oscilloscope. The oscilloscope created by my supervisor which utilises and arduino nano to transmit data to the laptop where it is displayed on a graphic user interface he developed in python.
Test 1 controlling only one LED with the anterior muscle on my forearm
Test 2 controlling two LEDs independently with both the anterior and posterior muscles
Test 3: controlling two LEDs independently with both the anterior and posterior muscles with a new varistor pot in the comparator for the posterior signals circuit
With the new pot I measured both the comparators resistance for the posterior (7.23k Ohms) and the anterior (7.23K Ohms) so as to allow for comparison and ease of setting up should I require at a later date. Although I will note that the system is very sensitive as to the level you can set it to which will allow you to turn on and off the LED and it is quite difficult at times to achieve the right level, also as you can see in test 3 although a little more refined there is still an issue with the posterior light activating when im trying to activate solely the anterior one. The next step I plan to execute is use the oscilliscope to find out the digital units of the peaks which may help in further reducing any accidental activation, I will also be experimenting with placement and proximity of the electrode pads.
The main circuit will be very similar to that of the one I used in my tabata timer except I will be adding in the signals from the instrumentation amplifiers. Currently this is what I’ve built. I’ve written basic LED and motor control codes to the chip to test it out and I’ve also written the tabata timer code and that too works (when I connect a switch to pin 14)
DT009 Final year project
Electromyography or EMG is an electrodiagnostic method for measuring and reading electrical impulses within skeletal muscles. Using EMG signals from various points on the residual arm I plan to control the open and close of a prosthetic hand.
The college provided me with electrode pads to aid in my experimenting but unfortunately there were no electrode probes available. While inspecting the pads various methods to connect onto them came to mind but none ensured a sound connection that could be guaranteed each time the project required to be reset.
As part of tracking my training performance I wear a heart rate monitor. The monitor unit can be un-clipped from the strap to allow it be cleaned or change batteries. It was upon un-cliping it during the week when I noticed the electrode pins were very similar to those on the pads of which the college provided to me.
Polar Heart Rate Sensor H1
H1 Sensor un-clipped
When trying the pad in the receiving end they fit perfectly. After a discussion with my grandmother about what these types of connections were it was pointed out to me that they were indeed snap fit buttons.
Equipment used in the production of the probe
After purchasing a packet of them I brought them home and tested them (and throughout the development process) for continuity.
Please see below pictures of the final electrode cables. I will endeavor to better document the process of the next one I make and post it here
The packet of buttons cost €2.10 for 6, the cable and end pin were provided by the college and the solder was my own purchased from Maplins. This cable I’ve estimated to cost under a euro to make where as some of the cables I looked at purchasing could run quite costly in comparison.
With the possible inclusion of FSR sesnors in this project a control method needs to be developed to correlate the readings from the sensors with tangible values.
There are many methods already existing that I could use but they require specialist equipment that is quite costly.
I have decided that the simplest way to obtain and quantify the force readings will be to take an object of known mass (confirmed by weighing it on a scales) then placing it on the FSR. It must also be noted that ensuring the base area of the object does not exceed that of the sensor is vital to ensure its true mass is read.
I believe this method to be the simplest and most efficient way to assign force values to digital units within my time and financial constraints.
There are many ways in which I can approach this electronically. I believe to start with to save time I will continue to use the dsPIC30f4011 as I am very familiar with it after my robotics module.
The main components I see thus far will be;
- For controlling the mechanics: inclusion of definitely servo motors and quite possibly a stepper.
- For the force ( grip pressure) applied by the hand I’ve come across these force sensitive resistors that I think might be perfect for the job
- For Feed back to the user as to the level of pressure applied there are 4 concepts I’m currently working on.
- An armband that tightens in proportion to that of the grip
- A vibrating armband to signify when the desired grip strength is reached
- A visual indicator of LEDs
- An audible indicator of some sort like a buzzer
Each of the above has their positive and negatives. The latter 2 are interesting but a potential user might not like the attention they might draw. Whereas the former 2 might have health implications such as; a tightening armband becoming a tourniquet and a buzzer could after prolonged use cause HAVS (Hand-Arm vibration syndrome).
As a result a lot of careful study will have to be done as to how to best approach the feedback system