The Virtual Piano Action: Design and Implementation

The design of a virtual piano action composed of a keyboard of motorized keys and a realtime mechanical system simulation is presented. Using this simulator, we have re-created certain aspects of the feel of the grand piano by numerically integrating the equations of motion of a simpli ed piano action in real time in a human-in-the-loop simulation scheme. In this paper, the simulation of the release and catch of the hammer is used to introduce the simulator architecture. The structure of a software module which manages the simulation of models with changing kinematic constraints is discussed, including a nite state machine driver which allows for the simulation of rigid-body systems which may take on various constraint conditions in a sequence dependent on run-time interaction.