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motors_init

Initialization - Zero reference

The Calibration Sequence can be started by triggering the safety event doCalibrating. This can be done by pressing the red button until this lights up. Press and hold the red button for 2 seconds, this will trigger the Safety Event doCalibrating. When finished with calibrating, press the red button once again. Press the green button to get back in normal operation mode.

Mechanical Limits of the Axis Motors - Upper limit

Upper limit calculation detail
Upper limit calculation shown below Upper limit calculation detail

L = 17.5
B = 15
s = 4

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

Leads to:

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

Solutions are:
t1 = 0.2736 → β = 30.6°
t2 = -2.1157 (neg. solution)

Hence, the maximum angle the axis can turn is 90° + β ≅ 120°.

Mechanical Limits of the Axis Motors - Lower limit

Lower limit of the Axis Motor measured on the Delta robot, γ is about 5°.

Mechanical Limits of the Tool Center Point Motor

The TCP rotation is also limited by two metall pins. The maximum turn angle is calculated as follows:
TCP limit

sin(γ/2) = r/R
γ=2*arcsin(r/R)= 0.0600 (rad) = 3.438°

That is the value for one side. The other side is identical, so the maximum turn angle is

β = 2*PI - 2 * 0.06 = 6.16 (rad) ≅ 353°.

motors_init.txt · Last modified: 2019/08/06 11:07 by visentin