Planar Motion Control

Orange object has 3 degrees of freedom in its planar motion: two linear and one angular displacements.
This mechanism can deal with two linear ones x, y.
They are controlled based on the polar coordinate system
The object center A is determined by distance r from a fixed point O and angle φ from fixed direction Ox.
x = r. cosφ
y = r.sinφ
The video shows how the mechanism moves the object to get distance r and then angle φ.
Lower motor controls r value.
Upper motor controls φ value.
There is a helical joint between pink slider and blue shaft.
Round rack on lower half of the yellow shaft allows independent operation of the motors.
Angular position of the object is unstable and needs a control device (not shown).