Abstract: A controller f or multi-DOF active vibration isolation accounts for plant uncertainties and payload disturbances using dynamic frequency-shaped sliding control. Modal decomposition rewrites a multi-DOF vibration control problem as a combination of modal problems. Modal parameters can be extracted. Target frequency-domain performance, e.g., a skyhook, is recast as a frequency-shaped sliding surface. Boundary layer approximation is examined. Skyhook can be robustly achieved. The manifold is also extends to adaptive vibration isolation without model reference. Nonlinear target dynamics of the same order as the plant can be attained. Control can be achieved without measuring excitation or knowing mass, stiffness and damping matrices. Control for plants subject to disturbances other than vibration can be achieved for any that can be described by equations the same character as those that describe mechanical dynamic systems. The target dynamics can be any, even non-linear.

Abstract: Time variation of communication delay may contribute directly to the instability of a distributed control system, such as a teleoperator system, for example, by communication paths themselves acting as sources of energy. The invention provides a distributed control system, such as a teleoperator system or a virtual reality system, that includes a master system, a slave system, and a communication system coupling the master system and the slave system. The communication system includes a bidirectional communication channel with time-varying delay, and an energy conservation filter coupled to the bidirectional communication channel for limiting a total energy provided by the communication system to the master and slave systems, thereby contributing to the overall stability of the system. The communication channel can be a data network, such as the Internet, which can exhibit significant variation in transmission delay.

Abstract: An adaptive control system uses a neural network to provide adaptive control when the plant is operating within a normal operating range, but shifts to other types of control as the plant operating conditions move outside of the normal operating range. The controller uses a structure which allows the neural network parameters to be determined from minimal information about plant structure and the neural network is trained on-line during normal plant operation. The resulting system can be proven to be stable over all possible conditions. Further, with the inventive techniques, the tracking accuracy can be controlled by appropriate network design.

Abstract: A telerobotic system provides a means for transmitting data between a master and a remote slave unit with a time delay therebetween. The master and slave unit form a closed loop in which motion commands are transmitted from the master to the slave and force data is transmitted back from the slave to the master. Stability is obtained over time delay by means of transforming the motion data into a wave representation in transmission between the master and slave. The signal from the master to the slave may be characterized generally as u=F+bx while the signal from the slave to the master may be characterized generally as v=F-bx where F equals the force imparted by the environment, x equals the velocity commanded by the master, and b is a characteristic wave impedance.