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power steering hacking

Discussion in 'Gen 2 Prius Accessories & Modifications' started by anthony.pray, Mar 3, 2008.

  1. V8Cobrakid

    V8Cobrakid Green Handyman

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    keep in mind that VSC is Vehicle Skid Control and also funtions to steer the car in case of a slide ( give extra torque in either direction)

    :boink:
     
  2. patsparks

    patsparks An Aussie perspective

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    Wouldn't the failsafe be that there is a person in the drivers seat keeping a vigilant lookout? BMW have a system under developement where the car can drive itself.
     
  3. anthony.pray

    anthony.pray New Member

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    Yah!!, looking over TIS I have found the torque sensor it is the 4 wires in the green plastic.
    thay are as fallows
    TRQ1 - Torque sensor 1
    TRQV - Power
    TRQ2 - Torque sensor 2
    TRQG - Ground

    TRQV - outputs 7.5 to 8.5 V

    TRQ1 and TRQ2 need to have a 0.3 V or less difference.

    Hear its the best part.
    If
    TRQ1 and TRQ2 are between 2.5 to 4.7 V this tell the Power Steering ECU
    to turn the car right.
    If
    TRQ1 and TRQ2 are between 0.3 to 2.5 V this tell the Power Steering ECU
    to turn the car Left.
    It looks like this should be easer then I thought.

    Car is all back together for tonight.
    Test for tomorrow.
    1) Grab voltages for controlled steering.
    2) Write simple app to simulate this back to the PS ECU.
    3) Will post video if I can get it working.

    Thanks to V8Cobrakid for the grate link!!!
     
    dnlshrn likes this.
  4. V8Cobrakid

    V8Cobrakid Green Handyman

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    yw. that does sound rather simple. that means that it's veriable where 2.5 is center?
     
  5. anthony.pray

    anthony.pray New Member

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    The plan is to use relays that are normal set to factory operation wiring.
    so in a case of failure the power is removed form the relays allow for normal operation to be restored.

    There will be much more to come.

    Remember this is just a "prototype" to show that the Prius could be a great platform for people, even DARPA.
    The great thing about the Prius is excluding the steering weal. form what I have been told the whole car is "drive by wire" so by finely getting the steering to be "by wire" you could very ease connecting in with a PC and drive the car... Without any new servo and actuators. The car already has them there. The reason for not making the steering by wire is, one word power, or lack of it. now are the breaks by wire or just supported by wire?
     
  6. ken1784

    ken1784 SuperMID designer

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    toyota.jp Æ’Nƒ‰ƒEƒ“ Æ’nÆ’CÆ’uÆ’Å Æ’bÆ’h > ˆÀ‘S«â€\
    Toyota is already selling Crown in Japan with the Lane Keeping Assist.
    We know Toyota can supply enough guarantee and have capability to pay millions of dollers for reparation about accidents.

    Ken@Japan
     
  7. anthony.pray

    anthony.pray New Member

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    yah!, well the center is 2.3 to 2.7 V

    [​IMG]
     
  8. kohnen

    kohnen Grumpy, Cranky Senior Member

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    If you plan on using relays, then you must be aware of this:

    As relays vibrate, the contacts that you think are closed aren't always - they will bounce around and chatter a bit due to the vibration of the car. This could cause some unexpected results.

    This means when you have the relays on and think that you are using your alternative design, you will get intermittent opens.

    When the relays are off and you think you are using the factory operation, you will get intermittent opens too.

    You will likely confuse the poor computer (likely causing immediate power steering shutdown due to a mis-match between the torque sensors).

    Contrary to what you might think, relays aren't a good way to make good solid electrical contact for computer signals.

    That said, good luck and be careful!
     
  9. ken1784

    ken1784 SuperMID designer

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    Failure is not only a power fail, but also in many places.
    I think you'll use CCD camera to detect highway lanes.
    A CCD has possibility to detect an artifacts or smear. You'll have to detect your lanes without any error.
    Smear - Wikipedia
    How are you going to detect correct lanes and to eliminate the smear?
    JP and EU Prius already have IPA, or Intelligent Parking Assist, and we can show Prius performance to people without any additional servo and actuators.
    And, it is in a walking speed and no one killed.

    We don't want anybody killed including yourself.

    Ken@Japan
     
  10. anthony.pray

    anthony.pray New Member

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    I was waiting for this post, let me make this clear right now.
    my plan is to get my car to drive a farley strait line with out my help. thats it..

    I am playing around with 2 different libraries.

    BlobDetection by v3ga
    Myron by Josh Nimoy
    The code is still very much in work but it gets closer every now and then.(I know....). Programing in Java, well it can be fun.I am hoping to set up a test reading of the Torque sensors, when the car is at highway conditions . Using diode porbs there is no chance of feedback in to the ECU.
     
  11. NoMoShocks

    NoMoShocks Electrical Engineer

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    Only in the OC! Your Prius is likely to become one of the better drivers in the Portland area. Especially if you can program it to signal before changing lanes.

    Also, I assume once your Prius can drive itself, it will count as it's own occupant, gaining you as the second occupant, access to HOV lanes. "Officer, give the ticket to my Prius, it was the one driving."
     
  12. anthony.pray

    anthony.pray New Member

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    Haha, another Portlander! The inspiration for the build, was the drive form Eugene to Seattle.
     
  13. ken1784

    ken1784 SuperMID designer

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    I see.
    Yours is something like GPS controlled cruising boat across an ocean, then go straight forever! :eek:

    Ken@Japan
     
  14. anthony.pray

    anthony.pray New Member

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    Good news the sensor work as expexted.
    with an out put of ~2.55v when there is no load, ~ 2.06 when turning left, and ~2.93 when turning right.
     
  15. anthony.pray

    anthony.pray New Member

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    A grate bit of work has been put in senesce the last post.
    I have a "demo" for you all, its not much but is showing the last test of this after noon on the line tracking software.
    the top left image is the live cam view with the boundary box of the line and the mid point line superimposed over it. the image in the top right is the blob detection threshold.
    The bottom graph is a reed from the TRQ1 sensor.



    I'm waiting on a D to A converter to show up, be for the drive system interface can be tested.

    Then its just some refining the line tracking and calibrating the drive system to it.

    At this point, pending no complication form the drive system, I may have a working system in a month or so.

    I am planing on using the DAC0808 D to A converter.
     
  16. V8Cobrakid

    V8Cobrakid Green Handyman

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    awesome :target:
     
  17. anthony.pray

    anthony.pray New Member

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    Ok, looking all over portland for some place that sells D/A converters
    but looking like I am stuck ordering off the net.
    looking like some time next week.
    I did a sample interface for you people.
    Using a potentiometer, a simple interface to the 06 Prius power Steering.
    [ame=http://www.youtube.com/watch?v=sq_uqhohL-s]YouTube - by wire Steering test #1[/ame]
    Going to see if I can hook it up to a servo for the time being.
    my hopes is that with the last two videos this will help to remove a lot of the smear a project like this can have.
     
  18. Flying White Dutchman

    Flying White Dutchman Senior Member

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    so there is no computer control but you directly drive the elec steering wheel motor?
    the prius is not giving any failure light on the dash? because the steering is doing something thats abnormal?
     
  19. anthony.pray

    anthony.pray New Member

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    There is no computer control yet. I am waiting for the D to A converter to show up. At which time I should have complete computer control.
    By allowing me to have computer control to the voltage supplied to the TRQ1/2 sensors.
    I am not directly controlling the steering wheel motor. I am modifying the voltage supplied by the TRQ1/2 sensors, to the power steering controller.
    by doing this it gives me a simple interface that can be easily disconnected.

    As for warning lights, the P/S light comes on if the voltages get to high or to low; a reboot of the car fixes it.

    One other thing is when the system is on (connected), is hard to turn the wheel, because of the TRQ1/2 sensors being overridden.
     
  20. Flying White Dutchman

    Flying White Dutchman Senior Member

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    do you already read the canbus data?