Adaptive-backstepping force/motion control for mobile-manipulator robot based on fuzzy CMAC neural networks

In this paper, an adaptive backstepping fuzzy cerebellar-model-articulation-control neural-networks control （ABFCNC） system for motion/force control of the mobile-manipulator robot （MMR） is proposed. By applying the ABFCNC in the tracking-position controller, the unknown dynamics and parameter variation problems of the MMR control system are relaxed. In addition, an adaptive robust compensator is proposed to eliminate uncertainties that consist of approximation errors, uncertain disturbances. Based on the tracking position-ABFCNC design, an adaptive robust control strategy is also developed for the nonholonomicconstraint force of the MMR. The design of adaptive-online learning algorithms is obtained by using the Lyapunov stability theorem. Therefore, the proposed method proves that it not only can guarantee the stability and robustness but also the tracking performances of the MMR control system. The effectiveness and robustness of the proposed control system are verified by comparative simulation results.

Advanced Credit-Assignment CMAC Algorithm for Robust Self-Learning and Self-Maintenance Machine

Smart machine necessitates self-learning capabilities to assess its own performance and predict its behavior. To achieve self-maintenance intelligence, robust and fast learning algorithms need to be em- bedded in machine for real-time decision. This paper presents a credit-assignment cerebellar model articulation controller (CA-CMAC) algorithm to reduce learning interference in machine learning. The developed algorithms on credit matrix and the credit correlation matrix are presented. The error of the training sample distributed to the activated memory cell is proportional to the cell’s credibility, which is determined by its activated times. The convergence processes of CA-CMAC in cyclic learning are further analyzed with two convergence theorems. In addition, simulation results on the inverse kinematics of 2- degree-of-freedom planar robot arm are used to prove the convergence theorems and show that CA-CMAC converges faster than conventional machine learning.

Optimization of fuzzy CMAC using evolutionary Bayesian Ying-Yang learning

Cerebellar model articulation controller(CMAC)is a popular associative memory neural network that imitates human’s cerebellum,which allows it to learn fast and carry out local generalization efficiently.This research aims to integrate evolutionary computation into fuzzy CMAC Bayesian Ying-Yang(FCMACBYY)learning,which is referred to as FCMAC-EBYY,to achieve a synergetic development in the search for optimal fuzzy sets and connection weights.Traditional evolutionary approaches are limited to small populations of short binary string length and as such are not suitable for neural network training,which involves a large searching space due to complex connections as well as real values.The methodology employed by FCMACEBYY is coevolution,in which a complex solution is decomposed into some pieces to be optimized in different populations/species and then assembled.The developed FCMAC-EBYY is compared with various neuro-fuzzy systems using a real application of traffic flow prediction.