Use analytical method, Freudenstein approach and design an acceptable four bar linkage

/in /by

A four-bar function generator is to be designed to guide an attic stairway from its stored position down to its deployed position where part of the ladder can slide down to reach the floor below. The figure below shows the proposed locations of the fixed

pivots
 Ao

and
 Bo, moving pivot B, and the angles 2, 3 (

input
 angles), 2

and
3 (

output
 angles) as well as the space constraint (roof joists). The starting positions of link 2 and 4 is up to you (1

and
1). Use analytical method, Freudenstein approach, and design an acceptable four bar linkage. Clearly, indicate all your selections and specify the length of all links. Also, include a drawing showing the stairway in the three positions.