Week 11 and 12

Weeks 11 and 12 we basically just tried to research on how to connect our throttle cut off system to an existing drive by wire throttle system car and where we will connect it on the circuit diagram. We met Simon a few times to try and figure out how we will achieve what we want and are still stuck on making the circuit. Once we make the circuit on paper, if we have enough time we will make the circuit on multisim and try and simulate our combined system of Warning Light, Buzzer and Throttle Cut off.

However I feel that we should be able to find out whether we will be able make a simulation on multisim in the deadline or not. We decided not to use picaxe chip as it requires a lot of programming and instead are going to try and connect the system using logic gates which are already programmed into a 555 timer chip. We feel that it will be a bit easier to do that and we 'should' be able to achieve the same results without having to learn programming in a small amount of time.

Week 10

Week 10 was our stage 2 demonstration which I considered to be the hardest one yet.
Our Three outputs as previously stated were
1) Seat Belt warning light - Seat Belt warning light must blink for 6 seconds from Ignition with 0.6 second frequency, with a 50% duty and a chime bell. If the IG. is turned off within 6 seconds, the warning light and chime bell must be 'off'. Below is the Seat belt warning light control circuit.

2) Buzzer System - If Seat Belt has not been fastened “After 15 second of ignition on status”. The buzzer will play the audio 3 times along with LED. If the seat belt is still not fastened, the audio and LED will flash after every 20 seconds.

3) Drive By Wire Throttle - Drive by wire throttle has no mechanical linkages, it saves weight, is more accurate and has better response times however the cost to make it is higher than a regular cable throttle. How it works is the driver presses gas pedal, there is a sensor attached to the pedal which measures how much it is pressed which then sends signal to ECU to turn the motor accordingly which in turn opens or closes the butterfly valve to allow for air to come in. There is another sensor after that which sends signal back to ECU to measure how much the butterfly valve is open or closed to ensure everything is working as it should. 
Below is an image of a gas pedal from a drive by wire throttle system with a accelerator position sensor.

Week 9

Coming back from two week mid-semester break, we decided to meet up on Monday and share with each other what we had done so far in the holidays and share all the research we had done to start preparing for stage 2 demonstration.

We knew what outputs we wanted which were:-

1) Buzzer 

2) warning light 

3) Throttle cut off over 20 kph when seat belt is not on (see last week's blog for logic table for desired results). 

We decided we were going to use Drive By Wire throttle system to cut off the throttle which will all be explained in next week's demonstration.