Embodiments of the invention relate to a hierarchical method for
generating force feedback effects. In one embodiment, a method comprises
receiving a first force contribution associated with a first (e.g.,
previous) position of a manipulandum; determining a second force
contribution associated with a second (e.g., current) position of the
manipulandum; and outputting a force signal to an actuator coupled to the
manipulandum, such that the actuator renders a feedback force having a
sum of the first and second force contributions. The method may further
include classifying force effects according to a predetermined
"hierarchy" (or "priority") scheme, whereby the second force contribution
is related to "high" priority force effects associated with the second
position, and the first force contribution is related to "low" priority
force effects associated with the first position. As such, computation
delay in outputting force feedback effects can be substantially reduced,
thereby enhancing the stability and performance of the underlying force
feedback system.