Actions
Forum Thread Details
  • Replies 42 replies
  • Subscribers 393 subscribers
  • Views 3630 views
  • Users 0 members are here
Related

Accelerometer Automated Locking system

Former Member

Hello,

 

I am Yuvish Chintaram from Mauritius Island.

 

Recently, I have applied to a university and my acceptance would be considered on a project that would help to contribute to my society.

My other friends are planting mangroves to help protect the marine ecosystem but I am more interested in science  and think to have find an interesting project.

 

A few months ago, an accident occured to a student that fell from a moving bus.(I have send you the link below.)

Surprisingly, two more people fell from a moving bus from the back emergency door after the earlier incident.

A solution was found by the Government that all bus should have an alarm and  that when the door opens an alarm will ring. But this does not solve the problem!

 

Hence, my idea was to incorporate a locking system that is fully autonomous. The system should lock the door while the bus is moving but unlock itself when the bus stops at a bustop.

I was thinking of using an accelerometer that will detect the acceleration of the bus that will relay to a circuit such that at a minimum value the latter will send a signal that will automatically lock or unlock the system.

eg. If(X>200)

      eletric lock is lock  

      else if (X<200)
       electric.lock is unlock

 

I am here to ask you if you could give me some advice and also if my current solution will work.

I would also be pleased to know your ideas about my project.( How would you answer it, etc..)

I would really appreciate if you could reply me as soon as possible.

 

http://news.islandcrisis.net/2015/03/17-year-old-student-keshnee-purmasing-died-after-falling-from-school-bus/

 

Regards

Yuvish Chintaram

  • Given that once the bus is at desired speed, the acceleration will effectively be zero, the same as if it where not moving so this would not be an ideal sensor to use

     

    A GPS measuring speed in any direction could be used as an alternative though.

     

    Your project is a worthy one but you need a different sensor

    Many new cars have a sensor that locks the doors once the car is over a set speed. This may give you somewhere to look.

     

    You could also tie into the but electronics (CAN BUS) and read it's speed

     

    Good luck

    peter

  • in reply to Robert Peter Oakes

    By far the best bet is use CAN bus info ot detect if the bus is moving, but only if the bus has CAN.

     

    If you are thinking of retrofitting to old vehicles you will need some other kind of sensor.

     

    One of the problems with adding safety systems to existing technology is that people apply very high standards to the new system. So you will need to ensure that your lock is very reliable - because people will count on it working and lean on the doors. You must also ensure that the doors unlock if the bus stops , or crashes etc so that people are never trapped inside it.

     

    I doubt that a one person project can do more than demonstrate feasibility of the idea and perhaps make a model.

     

    It is  a good idea - many cars already have such a system - are you sure that it is not available on new buses.

     

    MK

  • Good idea to use your efforts in science.

     

    An alternative is to have the door controlling the vehicle.

    If the door is not shut the vehicle cannot move ...

     

    You could use an external sensor to detect movement of the vehicle completely independant of any systems on the vehicle.

    GPS or a IR laser to the roadway would detect movement.

     

    Any system you design will need to include several methods for fitting to various type of vehicles.

    However the final application should be outside of the scope of the project, since it will need to be fitted by a qualified Automotive Engineer.

     

    Our buses all have door on the side and they tend to open sideways, which minimises this tragedy.

     

    Mark

  • in reply to Robert Peter Oakes

    Oh yes I have not thought of this. Constant speed means 0 acceleration.


    But since I will attach the accelerometer to the bus, i will also have to take into consideration the vibration of the bus.

    And I think The vibration when it will move and when it is steady are different?

    What do you think?
    Unfortunately the bus do not have CAN.
    And not all bus here have this locking system. I will try with the accelerometer first then i will see.
    Can you give me some advice with the sketch?
    I will have to use a relay to operate the electric lock.

     

    Regards

  • in reply to mcb1

    Hello

    I am really pleased for your advice.

     

    Unfortunately, the bus do not have CAN.

    But i really wanted to try it with the accelerometer.

    Then i will see it it works or not, and i can learn from that.

     

    Do you have an idea how the sketch will be?

    I can also include an override switch to the driver just in case. And i will use a relay to operate the electric lock.

    Regards

  • in reply to michaelkellett

    Hello

    I am really pleased for your advice.

     

    Unfortunately, the bus do not have CAN.

    But i really wanted to try it with the accelerometer.

    Then i will see it it works or not, and i can learn from that.

     

    Do you have an idea how the sketch will be? I am not so good in sketch image

    I can also include an override switch to the driver just in case and use a relay to operate the electric lock.

    Regards

  • I would recommend against the accelerometer approach, the kind of vibrations you are using to detect road surface imperfections during movement could easily be created by a stampede of people trying to get out. Of the suggestions made so far, GPS seems about the best IMHO.

     

    Also think about the duty cycle of your looking mechanism, as it will be releasing and relocating every time the vehicle comes to a standstill.

     

    When considering the locking mechanism look into fail-safe mechanisms. At least the lock will fail into safe condition (where the door opens) should any system damage occur.

  • in reply to gadget.iom

    Paul, I agree that there is lot of complex math with accelerometer than GPS. The better solution is with both, as the GPS is not really always available, maybe problems with satellite and so on. With accelerometer the better solution IMHO is that, based on experimental approach it is created a sort of specific profile in the different conditions of movements. Instead, about the problem of locking / unlocking the door only when it is the worth, I think there are two considerations:

     

    1 - The door should be unlocked after a minimum number of seconds the system is stable in the previous set "unlocking conditions" to avoid continuous lock / unlock

    2 - In general, the unlocking not only at the bus stop but in more other conditions - e.g. semaphore stop, too slow movement (so no risk occur), temporary stop for any reason - should be strongly took in account to avoid the opposite situation than what the project should defend: people trapped in the bus just because it has not yet reached the unlocking door status nearby the bus stop image

     

    Last I think that - for a general security approach - the door should be normally unlocked so that the lock mechanism is a specific action. Is something occurs to the system (crash, power-off, borken etc.) the doors are released instead of remaining locked forever.

     

    Enrico

  • in reply to gadget.iom

    But i have never used a GPS before.
    How can you help me

  • in reply to balearicdynamics

    ok lets say we use a GPS.
    But how would you integrate it in the circuit?
    How the sketch will be?
    I am new to all of this image help