Weight Update Process Research Articles

An error path delay compensated delayless subband adaptive filter architecture

The delayless subband adaptive filter has no transmission delay. Its closed-loop configuration converges close to the minimum residual error using feedback from the fullband error signal, but its stability and convergence rate are limited by the error path delay. This paper systematically analyzes the subband/fullband weight transformation and the subband weight update process, investigates the adverse influences of the error path delay, and then introduces a closed-loop block update algorithm with error path delay compensation. Simulation results for an acoustic echo cancellation application confirm that this modified algorithm rapidly converges to small residual error with low computational complexity.

Neural-network control of mobile manipulators

In this paper, a neural network (NN)-based methodology is developed for the motion control of mobile manipulators subject to kinematic constraints. The dynamics of the mobile manipulator is assumed to be completely unknown, and is identified online by the NN estimators. No preliminary learning stage of NN weights is required. The controller is capable of disturbance-rejection in the presence of unmodeled bounded disturbances. The tracking stability of the closed-loop system, the convergence of the NN weight-updating process and boundedness of NN weight estimation errors are all guaranteed. Experimental tests on a 4-DOF manipulator arm illustrate that the proposed controller significantly improves the performance in comparison with conventional robust control.