motors_init

Initialization - Zero reference

During homing the robot has to set his zero position. Zero position is choosen as the point where all three arms of the robot are in horizontal position.

Mechanical Limits of the Axis Motors - Upper limit  Upper limit calculation shown below Upper limit calculation detail

The mechanical dimensions are given by L = 0.0175m, B = 0.015m, s = 0.006m. The upper limit can be calculated as follows:

(1) tan(β) = sin(β) / cos(β) = (B - y) / L
(2) cos(β) = s / y

Substitute (2) into (1) to get:

(3) L * sin(β) - B * cos(β) = -s

Using following trigonometric formulas in (3):

(4) t = tan(β / 2)
(5) sin(β) = 2 * t / (1 + t^2)
(6) sin(β) = (1 - t^2 / (1 + t^2)

(7) (s + B) * t^2 + 2 * L * t + (s - B) = 0

Solutions are:

t1 = 0.2264 -> β = 0.445
t2 = -2.1157 (neg. solution)

Hence, the maximum angle the axis can turn is π/2 + β ≅ 2.016.

Mechanical Limits of the Axis Motors - Lower limit

For the lower limit of the Axis Motor the angle γ is measured to be about 5°. 