An apparatus comprising: a base ; a motion platform ; a pivot joint positioned between and connected to the base and the motion platform ; a plurality of active devices , wherein each of the plurality of active devices is positioned between and connected to the motion platform at a corresponding first connection point and to the base at a corresponding second connection point, and wherein each of the plurality of active devices is capable of exerting a force on the motion platform at its corresponding first connection point; and a plurality of transducers , wherein each of the plurality of transducers is positioned between and connected to the motion platform at a corresponding third connection point and to the base at a corresponding fourth connection point, and wherein each of the plurality of transducers is aligned with a corresponding one of the plurality of active devices and the pivot joint such that: the third and fourth connection point of each of the plurality of transducers are located in a geometric plane with a pivot point associated with the pivot joint and the first and second connection points of the corresponding one of the plurality of active devices , and an output signal associated with each of the plurality of transducers remains proportional to the length of the corresponding one of the plurality of active devices between its first and second connection points. a base ; a motion platform ; a pivot joint positioned between and connected to the base and the motion platform ; a plurality of active devices , wherein each of the plurality of active devices is positioned between and connected to the motion platform at a corresponding first connection point and to the base at a corresponding second connection point, and wherein each of the plurality of active devices is capable of exerting a force on the motion platform at its corresponding first connection point; and a plurality of transducers , wherein each of the plurality of transducers is positioned between and connected to the motion platform at a corresponding third connection point and to the base at a corresponding fourth connection point, and wherein each of the plurality of transducers is aligned with a corresponding one of the plurality of active devices and the pivot joint such that: the third and fourth connection point of each of the plurality of transducers are located in a geometric plane with a pivot point associated with the pivot joint and the first and second connection points of the corresponding one of the plurality of active devices , and an output signal associated with each of the plurality of transducers remains proportional to the length of the corresponding one of the plurality of active devices between its first and second connection points. the third and fourth connection point of each of the plurality of transducers are located in a geometric plane with a pivot point associated with the pivot joint and the first and second connection points of the corresponding one of the plurality of active devices , and an output signal associated with each of the plurality of transducers remains proportional to the length of the corresponding one of the plurality of active devices between its first and second connection points. <EOS>