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tank drive system — Parallax Forums

tank drive system

ArchiverArchiver Posts: 46,084
edited 2001-07-23 07:24 in General Discussion
I am building a telerobot using the transmitter and receiver from an R/C
airplane. I want the steering to be tank like. To turn, one motor or the
other would slow down depending on direction of turn needed. When in the
neutral position, simple left or right would have one motor reverse while
the other would go foward having the robot spin in place. What is the best
way to accomplish this? I am using a BS2, but the code involved seems
messy. Is there a chip out there that will convert the pulses from two
channels of the receiver to 2 channels of PWM and forward and reverse for
each? I have designed the drive system to handle the current so the control
signals is all I need. Thanks in advance for all your help.
Rusty

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2001-07-22 21:11
    This is for a "tank steering" .
    One two channel mixing joystick to control all movements

    Algorithm may be something like:
    Deadband is optional and should prevent on=off fluctuations

    initial declarations
    Neutral constant 'neutral value for center Joysticks -no move
    Deadband constant 'value for deadband allowed
    LeftMotor variable 'output for Left Motor
    RightMotor variable 'output for Right Motor
    FwRv variable 'input value from forward-reverse channnel joystick
    Yaw variable 'input value from left-right channel jopystick

    loop
    read FwRv
    read Yaw

    if if FwRv < ( Neutral+Deadband ) or FeRv > ( Neutral-Deadband ) then
    FwRv= Neutral
    if if Yaw < ( Neutral+Deadband ) or Yaw > ( Neutral-Deadband ) then
    Yaw= Neutral

    LeftMotor= Neutral + ( FwRev - Neutral ) + (Yaw - Neutral )
    RightMotor= Neutral + ( FwRev - Neutral ) - (Yaw - Neutral )

    gotoloop

    this should do the following mixing movements

    Forward
    \|/
    Left ) + ( Right
    Turn /|\ Turn
    Reverse

    where + is the joystick in the center (neutral);
    ( is a clockwise spin
    ) is counterclockwise spin
    the straight lines points a direction from the +

    Another simple way to have a easy to pilot "tank steering" system is to
    use two sliding potentiometers with a central "click" and mounting side
    by side like a 2 motor boat style command lever throtle and forget
    "mixing softwares".

    ACJacques

    Rusty wrote:
    >
    > I am building a telerobot using the transmitter and receiver from an R/C
    > airplane. I want the steering to be tank like. To turn, one motor or the
    > other would slow down depending on direction of turn needed. When in the
    > neutral position, simple left or right would have one motor reverse while
    > the other would go foward having the robot spin in place. What is the best
    > way to accomplish this? I am using a BS2, but the code involved seems
    > messy. Is there a chip out there that will convert the pulses from two
    > channels of the receiver to 2 channels of PWM and forward and reverse for
    > each? I have designed the drive system to handle the current so the control
    > signals is all I need. Thanks in advance for all your help.
    > Rusty
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and Body
    of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
  • ArchiverArchiver Posts: 46,084
    edited 2001-07-22 22:29
    On 7/22/01 at 2:59 PM, lineman@m... (Rusty) wrote:

    > I am building a telerobot using the transmitter and receiver from an R/C
    > airplane.

    Don't get caught. The FCC approves 72.xxxMHz bands for RC aircraft use, and
    75.xxxMHz for RC ground (boats, cars, etc). Flip-flopping them ain't quite
    kosher. If the gear is made by one of the bigger manufacturers (Futaba,
    Airtronics, Hitec) you may be able to send it back and get it converted.

    FYI...

    -dave

    hate is bad
    dave paton http://www.dpaton.net dave at ieee dot org
  • ArchiverArchiver Posts: 46,084
    edited 2001-07-23 07:24
    Hi Rusty,

    check out the following links for one way to do what you want:
    http://members.tripod.com/~divelec/mtrctrlint.html
    http://members.tripod.com/~divelec/hbridge.html

    or these links to do it another way:
    http://divelec.tripod.com/rcic2/rcic-2.html
    http://divelec.tripod.com/mc/mc6_specs2.html

    Carl
    Diverse Electronic Services


    Original Message
    From: Rusty <lineman@m...>
    To: <basicstamps@yahoogroups.com>
    Sent: Sunday, July 22, 2001 12:59 PM
    Subject: [noparse][[/noparse]basicstamps] tank drive system


    > I am building a telerobot using the transmitter and receiver from an R/C
    > airplane. I want the steering to be tank like. To turn, one motor or the
    > other would slow down depending on direction of turn needed. When in the
    > neutral position, simple left or right would have one motor reverse while
    > the other would go foward having the robot spin in place. What is the
    best
    > way to accomplish this? I am using a BS2, but the code involved seems
    > messy. Is there a chip out there that will convert the pulses from two
    > channels of the receiver to 2 channels of PWM and forward and reverse for
    > each? I have designed the drive system to handle the current so the
    control
    > signals is all I need. Thanks in advance for all your help.
    > Rusty
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
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