This paper presents sensing-knowledge-command(SKC) fusion as a fundamental paradigm of implementing cooperative control for an advanced man-machine system. SKC fusion operates on the "SKC fusion network", representing the connection between sensory data to commands through knowledge. Sensing, knowledge, and command of a human and a machine are merely tapped into the network to provide inputs or stimuli to the network. Such stimuli automatically invokes a SKC fusion process and generates a fused ouput for cooperative control. Once invoked by stimuli, the SKC fusion process enforces the network to converge to a new equilibrium state through the network dynamics composed of data fusion, feature transformation, and constraint propagation. The SKC fusion process thus integrates redundant information, maintains consistency of the network, identifies faulty data and concepts, and specifies those concepts to be strengthened (for enhancing command reliability) through sensor planning.