The inventive technology, in its various embodiments, relates to improved multi-axis input devices such as joysticks, and associated multi-axis optical displacement measurement means. Certain embodiments of the input devices may comprise elements movable with respect to each other in at least, e.g., three degrees of freedom and comprise ionically conductive elements that are utilized to generate a position signal in, e.g., at least three, or at least six degrees of freedom. Various ergonomic configurations of six axis joystick embodiments which may be facilitated by the compact design of the transducer means are disclosed. Certain embodiments of the input device technology may provide feedback (e.g., relative to force applied to an item whose position is controlled by an operator) to the operatore. Means for dynamically adjusting coordinate transformations for construction machinery control are also disclosed.