Abstract: In an artificial limb system having an actuator coupled to a joint for applying a torque characteristic thereto, a control bandwidth of a motor controller for a motor included in the actuator can be increased by augmenting a current feedback loop in the motor controller with a feed forward of estimated back electromotive force (emf) voltage associated with, the motor. Alternatively, the current loop is eliminated and replaced with a voltage loop related to joint torque. The voltage loop may also be augmented with the feed forward of estimated back emf, to improve the robustness of the motor controller.

Abstract: In an artificial limb system having an actuator coupled to a joint for applying a torque characteristic thereto, a control bandwidth of a motor controller for a motor included in the actuator can be increased by augmenting a current feedback loop in the motor controller with a feed forward of estimated back electromotive force (emf) voltage associated with, the motor. Alternatively, the current loop is eliminated and replaced with a voltage loop related to joint torque. The voltage loop may also be augmented with the feed forward of estimated back emf, to improve the robustness of the motor controller.

Abstract: In an artificial limb system having an actuator coupled to a joint for applying a torque characteristic thereto, a control bandwidth of a motor controller for a motor included in the actuator can be increased by augmenting a current feedback loop in the motor controller with a feed forward of estimated back electromotive force (emf) voltage associated with, the motor. Alternatively, the current loop is eliminated and replaced with a voltage loop related to joint torque. The voltage loop may also be augmented with the feed forward of estimated back emf, to improve the robustness of the motor controller.

Abstract: A low-cost, high-speed data switching system and method uses several parallel switching systems or fabrics. In one of various embodiments, for example, the constituent data flows in a data stream can be selectively routed to a switching fabric that has the lowest input data rate. Data flows can be assigned to the various switching fabrics so as to balance the amount of data passing through each parallel system. Data flows can be re-assigned on an as-needed basis to insure maximum throughput. In the case where a data flow initially routed into one switching fabric must be re-routed to a different fabric, the ordering of data packets can be preserved by withholding the transfer of packets through the second fabric until the packets previously sent into the first fabric have cleared. Methods and apparatus of the present invention find application to parallel computing as well.

Abstract: A low-cost, high-speed data switching system and method uses several parallel switching systems or fabrics. In one of various embodiments, for example, the constituent data flows in a data stream can be selectively routed to a switching fabric that has the lowest input data rate. Data flows can be assigned to the various switching fabrics so as to balance the amount of data passing through each parallel system. Data flows can be re-assigned on an as-needed basis to insure maximum throughput. In the case where a data flow initially routed into one switching fabric must be re-routed to a different fabric, the ordering of data packets can be preserved by withholding the transfer of packets through the second fabric until the packets previously sent into the first fabric have cleared. Methods and apparatus of the present invention find application to parallel computing as well.

Abstract: A low-cost, high-speed data switching system and method uses several parallel switching systems or fabrics. In one of various embodiments, for example, the constituent data flows in a data stream can be selectively routed to a switching fabric that has the lowest input data rate. Data flows can be assigned to the various switching fabrics so as to balance the amount of data passing through each parallel system. Data flows can be re-assigned on an as-needed basis to insure maximum throughput. In the case where a data flow initially routed into one switching fabric must be re-routed to a different fabric, the ordering of data packets can be preserved by withholding the transfer of packets through the second fabric until the packets previously sent into the first fabric have cleared. Methods and apparatus of the present invention find application to parallel computing as well.

Abstract: A neural network solution for routing calls through a three stage interconnection network selects an open path through the interconnection network if one exists. The neural network solution uses a neural network with a binary threshold. The weights of the neural network are fixed for all time and therefore are independent of the current state of the interconnection network. Preferential call placement strategies are implemented by selecting appropriate external inputs to the neural network. An interconnection network controller stores information reflecting the current usage of the interconnection network and interfaces between the interconnection network and the neural network.

Abstract: An adaptive transversal filter is characterized by a first adaptive filter for generating a plurality of estimated impulse response coefficients representing an impulse response of a transmission path. An averaging circuit is coupled with the first adaptive filter, and generates a plurality of average estimated impulse response coefficients having values in accordance with the average values over a most recent time interval of associated ones of the estimated impulse response coefficients, and a second adaptive filter receives the average estimated coefficients. The average estimated impulse response coefficients more closely represent and have less variance with respect to the actual impulse response of the transmission path than do the estimated coefficients, and the second filter generates an estimate of an echo signal through a process including convolution of the average estimated coefficients and an input signal.

Abstract: A double talk detector for echo cancellers monitors the ratio of four wire transmit in energy to transmit out energy (ERLE), along with the change and direction of change of an estimated impulse response, to control updating of the estimated inpulse response. When the ERLE is low and the directional change of the impulse response is high, indicating an end path switch, the double talk detector enables the estimated impulse response to be updated. If the directional change of the impulse response and the ERLE are both low, indicating the occurrence of double talk, the detector inhibits updating of the impulse response until either the ERLE becomes sufficiently high, indicating single talk, or the directional change of the impulse response becomes sufficiently large, indicating an inconverged state of the canceller. The arrangement allows convergence of the echo canceller to be properly controlled both in response to double talk and to changes in the impulse response of the end path.