The invention relates to improved multi-axis joysticks and associated multi-axis optical displacement measurement means. The joystick 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. Means for dynamically adjusting coordinate transformations for construction machinery control are also disclosed.