Page 1 of 2 12 LastLast
Results 1 to 10 of 19

Thread: New Project Help

  1. #1
    Newbie
    Join Date
    Dec 2008
    Posts
    15

    New Project Help

    Hi All. Hope everyone had a great Christmas.
    My latest project is for a car that I am building from scratch. It started as a pile of tubing and some scribbly sketching on a table. I'm using a Ford 302 and a T5z 5 speed manual transmission. What I would like to do is to shift the trans electrically. I thought of using stepper motors but I know that they can forget where they are if stalled so I think I will use a geared 24v motor. The trans uses one shaft to shift. The shaft moves fore and aft or rotates to position the gears. I plan on using opto switches to provide feed back for shaft position.
    So ... 3 opto switches to indicate rotation. SR1, SR2, SR3.
    3 opto switches to indicate fore and aft position. SL1, SL2, SL3.
    1 opto switch to indicate clutch position. SC1
    1 opto switch for UP shift. SU1
    1 opto switch for Down shift. SD1
    1 MO pushbutton switch for Reverse. SREV1
    2 electrically actuated Micro Clutches (common in printers) EC1, EC2
    1 speed sensor signal fron rear wheel for Reverse and "No you really don't want to down shift to 1st gear at 60 mph"

    Neutral would be SL2 and SR1 or SR2 or SR3. (the fore and aft center position is neutral regardless of rotation)
    1st gear would be SR1/SL1
    2nd gear would be SR1/SL3
    3rd gear would be SR2/SL1
    4th gear would be SR2/SL3
    5th gear would be SR3/SL1
    Reverse would be SR3/SL3

    Now a very important note: the shaft must be in position SL2 before the shaft can be rotated.

    How do I move the shaft? I use a dc gear reduction motor coupled to a shaft. The shaft has two micro clutches, one for SR and one for SL. Power is transmitted to the shifting shaft in the trans by timing belts. Rotational force uses a splined shaft (so it can slide back and forth) and the fore and aft force uses a lead screw and nut.
    Power up the motor, energize EC1 and the shifting shaft rotates, energize EC2and the lead screw nut turns which causes the shaft to move fore or aft.

    So after powerup of the system (before engine start) push in the clutch (SC1 ON) and the shifter initializes by going to the SR1/SL2 position (neutral and positioned for 1st gear). Now how it does that depends on where the trans was on shutdown.

    If the trans was in 1st gear it would go like this:
    Clutch in
    Motor - On, Clockwise
    EC2 - ON until SL2 turns ON then EC2 OFF
    Motor - off
    Neutral indicated on LCD screen

    If the trans was in 2nd gear:
    Clutch IN
    Motor - ON Counter Clockwise
    EC2 - ON until SL2 turns ON then EC2 OFF
    Motor - off
    Neutral indicated on LCD screen

    To shift into 1st from neutral:
    Clutch in
    Motor - On, Counter Clockwise
    EC2 - ON until SL2 turns ON then EC2 OFF
    Motor - off
    1st gear indicated on LCD screen

    To shift from 2nd to 3rd:
    Clutch IN
    SU1 - Momentary ON (or could be latching if it would makes things easier)
    Motor - On, Clockwise
    EC2 - ON until SL2 turns ON then EC2 OFF
    Motor - off
    Motor - On, Counter Clockwise
    EC1 - ON until SR2 turns ON then EC1 OFF
    Motor - off
    Motor - On, Clockwise
    EC2 - ON until SL3 turns ON then EC2 OFF
    Motor - off
    3rd gear indicated on LCD screen


    And so on. You can see that the direction of the motor may have to be changed up to 3 times in one shift. I could possibly use 2 motors but space is limited.

    So now my questions.
    Can the brain handle this?
    Any suggestions on how to word the logic section of the code ( or any of the code for that matter)?
    Do I need to use an opto isolator or can I just hook them to the analog inputs direct?
    Just in case a shift gets stuck (or maybe looses power) I need a way to cancel the shift and go back to neutral, both automatically maybe based on current draw or manually by pushing a button (maybe on the LCD screen).
    Any help would be appreciated and when this is project is up and running I'll post all the info I have.
    General thoghts?
    Phone # of a good shrinK

  2. #2
    Constant Bitrate
    Join Date
    Jun 2008
    Location
    Georgia, USA
    Posts
    188
    Quote Originally Posted by quick503 View Post
    ...Phone # of a good shrinK
    1-800-nuts-r-us

    Seriously, that is an ambitious project. I don't have anything to offer as far as coding goes, but I do have a suggestion.

    You might consider some sort of throttle-limit switch just in case of a missed shift. That would keep you from spilling 302 guts all over the road due to over-revving (translate: been there, done that).
    Thanks,

    Dan

  3. #3
    Constant Bitrate mx270a's Avatar
    Join Date
    Aug 2003
    Location
    Iowa
    Posts
    167
    I use a FB to control steering on a farm tractor. I have two relays, each going to one side of a solenoid that controls a hydraulic valve. I also have a sensor to tell me what angle the steer axle is currently at. All I do is feed a target steer angle to the logic and it will issue left or right commands to get the steer axle to that target point.

    Personally, I'd use two potentiometers to determine where the shifter is currently. Seems easier to read two inputs to determine the location than to read through the 6 switches.

  4. #4
    Newbie
    Join Date
    Dec 2008
    Posts
    15
    Over Rev protection sounds like a great idea (not that I have EVER missed a shift ).
    Using pots sounds like a good idea. I just wonder how temperature will effect the readings. The temperatures could go from below freezing to 150 degrees or so.

  5. #5
    Newbie
    Join Date
    Dec 2008
    Posts
    15
    I know I'm getting this wrong. Can someone point me in the right direction? I want to use an analog input to turn the output on or off. If the analog input "sees" more than 4v (but less than 5v) then the output would turn ON ... less than 4v then OFF.
    This is what I have so far.

    <!-- Begin Digital Output Instances -->
    <iochannel id="Output0" port="0" brain="My Fusion Brain 0" type="digital_output">
    <defaults defaultstate="off"></defaults>
    </iochannel>
    <!-- End Digital Output Instances -->

    <!-- Begin Analogue Input Instances -->
    <iochannel id="Input0" port="0" brain="My Fusion Brain 0" type="analogue_input">
    <options history="0" auto_average="false"></options>
    </iochannel>
    <!-- End Analogue Input Instances -->
    </io>

    <logic>
    <!-- Begin Logging Setup -->
    <all_logging>
    </all_logging>
    <!-- End Logging Setup -->

    <!-- Begin Variable Declarations -->
    <all_variables>
    <variable name="Variable_Analogue_Input_0">0</variable>
    </all_variables>
    <!-- End Variable Declarations -->

    <!-- Begin Logic Declarations -->
    <all_statements>
    <if fire_on="logic" minimum_delta_vote_time="100" id="Logic for Analogue Input 0">
    <parameter1>
    <boolean_operation type="greater than">
    <parameter1>
    <variable do="get" name="Variable_Analogue_Input_0">
    </parameter1>
    <parameter2>
    <number>4</number>
    </parameter2>
    </boolean_operation>
    </parameter1>


    </if>
    </all_statements>
    <!-- End Logic Declarations -->
    </logic>

  6. #6
    Newbie
    Join Date
    Dec 2008
    Posts
    15
    Couple of more questions. If I change the software by editing the xml file when does it take effect? Do I need to remove power from the FB (reboot it)/
    If I use the configurator to add just a digital output to be default "ON" should I be able to read 12v on the output pins?
    Thanks

  7. #7
    Fusion Brain Creator 2k1Toaster's Avatar
    Join Date
    Mar 2006
    Location
    Colorado, but Canadian!
    Posts
    10,049
    You are on the right track, but you want "if input X is greater than Y volts", and what you have is "if variable Z is greater than Y volts".

    So change that variable to the input you want. Also are you editing that manually?

    All that statement will then do is check if the input is greater than 4v. If it is or isnt, it will go woohoo and move to the next statement. To make it turn on/off an input you will need to add some then and antithens.

    So the then would be when it evaluates true, so turn output ON.
    The Antithen would be when it evaluates to false, so turn output OFF.
    Fusion Brain Version 6 Released!
    1.9in x 2.9in -- 47mm x 73mm
    30 Digital Outputs -- Directly drive a relay
    15 Analogue Inputs -- Read sensors like temperature, light, distance, acceleration, and more
    Buy now in the MP3Car.com Store

  8. #8
    Fusion Brain Creator 2k1Toaster's Avatar
    Join Date
    Mar 2006
    Location
    Colorado, but Canadian!
    Posts
    10,049
    Quote Originally Posted by quick503 View Post
    Couple of more questions. If I change the software by editing the xml file when does it take effect? Do I need to remove power from the FB (reboot it)/
    If I use the configurator to add just a digital output to be default "ON" should I be able to read 12v on the output pins?
    Thanks
    To make changes all you need to do is restart MDX.

    If you make an output have default on, then as soon as MDX starts, that output will turn on. The LED will light if the jumper has not been removed. The output pins will be whatever power voltage on the DC Jack all the time (regardless of output state). If you are powering via USB, and have no DC jack connected, no voltage will appear on the output pins. When an output turns on, the ground pin activates and completes the circuit turning things on.
    Fusion Brain Version 6 Released!
    1.9in x 2.9in -- 47mm x 73mm
    30 Digital Outputs -- Directly drive a relay
    15 Analogue Inputs -- Read sensors like temperature, light, distance, acceleration, and more
    Buy now in the MP3Car.com Store

  9. #9
    Newbie
    Join Date
    Dec 2008
    Posts
    15
    I just tried using the configurator and Ninja Kitty to make an xml file. I added the Fusion Brain and one digital output. I set the default state to ON but it wouldn't keep the setting so I edited it manually. I started MDX but no light. I do have the 12v power supply attached. I need to get this to work so I can have someplace I can go to to say "I know this works" when trouble shooting. Do you have any experience using opti sensors? Also can I use the 5v pin on the analog input to drive the signal high?

  10. #10
    Newbie
    Join Date
    Dec 2008
    Posts
    15
    OK, I used this in the Logic area and it worked.

    <all_statements>
    <if fire_on="logic" minimum_delta_vote_time="100" id="Root Function #">
    <boolean_operation type="greater than">
    <parameter1>
    <analogue id="SC1" time="0"></analogue>
    </parameter1>
    <parameter2>
    <number>4</number>
    </parameter2>
    </boolean_operation>
    <then>
    <do function="Trigger Output" functionTargetID="D0" vote_opinion="On" vote_priority="High"></do>
    </then>
    </if>
    </all_statements>

    I can't seem to figure out how to get the anti-then part. Do you do another <if>, </if> section but use "not"?

    <if fire_on="logic" minimum_delta_vote_time="100" id="Root Function #">
    <boolean_operation type="not">
    <parameter1>
    <boolean_operation type="greater than">
    <parameter1>
    <analogue id="SC1" time="0"></analogue>
    </parameter1>
    <parameter2>
    <number>4</number>
    </parameter2>
    </boolean_operation>
    <then>
    <do function="Trigger Output" functionTargetID="D0" vote_opinion="off" vote_priority="High"></do>
    </then>
    </if>

Page 1 of 2 12 LastLast

Similar Threads

  1. Replies: 18
    Last Post: 07-26-2006, 09:50 AM
  2. DIN compatable PC project
    By don-m in forum Worklogs
    Replies: 4
    Last Post: 10-23-2005, 10:11 AM
  3. New Project: Contrast Mediaplayer
    By pplante in forum Software & Software Development
    Replies: 26
    Last Post: 07-07-2004, 11:06 AM
  4. Hello!! CarPC project pics inside.
    By bobbykokinos in forum Newbie
    Replies: 11
    Last Post: 03-29-2004, 11:44 AM
  5. RLion Project Webpage
    By Reactor in forum General MP3Car Discussion
    Replies: 0
    Last Post: 02-18-2004, 05:43 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •