With respect to the designing requirements and constraints of the mechanism

two options

the RSSR mechanism and the dual-RSSR mechanism

are constructed based on CATIA with the top-down design ideas.The kinematic simulation of the model is conducted.The motion transmission characteristics of the two schemes are compared.A conclusion is drawn that for either RSSR mechanism or dual-RSSR mechanism the input and the output keep linear under the condition that the input angle is small.And for the dual-RSSR mechanism the output is approximately the same as its input by optimizing parameters of the mechanism structure.But for RSSR mechanism

those depend on the initial condition.