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Newbie arduino 6dof

Discussion in 'New users start here - FAQ' started by novio8, Jun 4, 2015.

  1. novio8

    novio8 New Member

    Joined:
    May 28, 2015
    Messages:
    8
    Location:
    sarajevo
    Balance:
    298Coins
    Ratings:
    +2 / 0 / -0
    My Motion Simulator:
    Arduino
    Hi,
    I'v builded my first 6dof Stewart platform as a starting point to real life sized platform
    and I stumbled already at some troubles.
    I'v assembled the platform using six standard servos and Arduino Mega. Servos work if I use
    standard sweep example code
    but I get no movement when I start the following code:

    #include <Servo.h>
    const float pi = 3.14159,
    theta_r = radians(48.0),
    theta_p = radians(23.2),
    theta_s[] = { -pi / 3, 2 * pi / 3, pi, 0, pi / 3, -2 * pi / 3},
    RD = 2.395,
    PD = 3.3,
    L1 = 1.0,
    L2 = 4.72,
    z_home = 4.25,
    servo_min = 3.5,
    servo_max = 5.5,
    servo_mult = 6,
    p[2][6] = {{PD * cos(pi / 6 + theta_p), PD * cos(pi / 6 - theta_p), PD * cos(-(pi / 2 - theta_p)), -PD * cos(-(pi / 2 - theta_p)), -PD * cos(pi / 6 - theta_p), -PD * cos(pi / 6 + theta_p)},
    {PD * sin(pi / 6 + theta_p), PD * sin(pi / 6 - theta_p), PD * sin(-(pi / 2 - theta_p)), PD * sin(-(pi / 2 - theta_p)), PD * sin(pi / 6 - theta_p), PD * sin(pi / 6 + theta_p)}
    },
    re[2][6] = {{RD * cos(pi / 6 + theta_r), RD * cos(pi / 6 - theta_r), RD * cos(-(pi / 2 - theta_r)), -RD * cos(-(pi / 2 - theta_r)), -RD * cos(pi / 6 - theta_r), -RD * cos(pi / 6 + theta_r)},
    {RD * sin(pi / 6 + theta_r), RD * sin(pi / 6 - theta_r), RD * sin(-(pi / 2 - theta_r)), RD * sin(-(pi / 2 - theta_r)), RD * sin(pi / 6 - theta_r), RD * sin(pi / 6 + theta_r)}
    };

    /*
    theta_r = angle between attachment points
    theta_p = angle between rotation points
    theta_s = orientation of the servos
    RD = distance to end effector attachment points
    PD = distance to servo rotation points
    L1 = servo arm length
    L2 = connecting arm length
    z_home = default z height with servo arms horizontal
    servo_min = lower limit for servo arm angle
    servo_max = upper limit for servo arm angle
    servo_mult = multiplier to convert to milliseconds
    p = location of servo rotation points in base frame [x/y][1-6]
    re = location of attachment points in end effector frame [x/y][1-6]
    */
    const int servo_pin[] = {9, 3, 5, 11, 6, 10};
    const int servo_zero[6] = {1710, 1280, 1700, 1300, 1680, 1300};
    /*
    servo_pin = servo pin assignments,
    servo_zero = zero angles for each servo (horizontal)
    */
    Servo servo[6];
    /*
    Servos 0, 2, 4: reversed (+ = down, - = up)
    Servos 1, 3, 5: normal (+ = up, - = down)
    */
    void setup()
    {
    //Serial.begin(9600);
    for (int i = 0; i < 6; i++)
    {

    servo.attach(servo_pin);
    servo.writeMicroseconds(servo_zero);
    }
    delay(1000);
    }

    void loop()
    {
    static float pe[6] = {0, 0, 0, radians(0), radians(0), radians(0)}, theta_a[6], servo_pos[6], q[3][6], r[3][6], dl[3][6], dl2[6];

    }
    /*
    pe = location and orientation of end effector frame relative to the base frame [sway, surge, heave, pitch, roll, yaw)
    theta_a = angle of the servo arm
    servo_pos = value written to each servo
    q = position of lower mounting point of connecting link [x,y,x][1-6]
    r = position of upper mounting point of connecting link
    dl = difference between x,y,z coordinates of q and r
    dl2 = distance between q and r
    */
    • Like Like x 1
  2. vell

    vell New Member

    Joined:
    Jun 8, 2015
    Messages:
    16
    Location:
    piter
    Balance:
    267Coins
    Ratings:
    +0 / 0 / -0
    My Motion Simulator:
    AC motor, 4DOF
    you yourself write the program for the controller ?