Showing papers by "Indian Institute of Technology, Jodhpur published in 1996"

On adaptive trajectory tracking of a robot manipulator using inversion of its neural emulator

Abstract: This paper is concerned with the design of a neuro-adaptive trajectory tracking controller. The paper presents a new control scheme based on inversion of a feedforward neural model of a robot arm. The proposed control scheme requires two modules. The first module consists of an appropriate feedforward neural model of forward dynamics of the robot arm that continuously accounts for the changes in the robot dynamics. The second module implements an efficient network inversion algorithm that computes the control action by inverting the neural model. In this paper, a new extended Kalman filter (EKF) based network inversion scheme is proposed. The scheme is evaluated through comparison with two other schemes of network inversion: gradient search in input space and Lyapunov function approach. Using these three inversion schemes the proposed controller was implemented for trajectory tracking control of a two-link manipulator. Simulation results in all cases confirm the efficacy of control input prediction using network inversion. Comparison of the inversion algorithms in terms of tracking accuracy showed the superior performance of the EKF based inversion scheme over others.

Kinetics and mechanism of oxidation of diols bybis(2,2′-bipyridyl) copper(II) permanganate

Abstract: Kinetics of oxidation of five vicinal, four non-vicinal diols, and one of their monoethers bybis(2,2′-bipyridyl) copper(II) permanganate (BBCP), has been studied. The vicinal diols yielded the products arising out of the glycol bond fission, while the other diols yielded the hydroxycarbonyl compounds. The reaction is first-order with respect to BBCP. Michaelis-Menten type kinetics were observed with respect to the diol. There is no effect of added 2,2′-bipyridine on the reaction. The oxidation of [1,1,2,2-2H4] ethanediol showed the absence of a primary kinetic isotope effect. A mechanism involving a glycol bond fission has been proposed for the oxidation of the vicinal diols. The other diols are oxidised by a hydride-transfer mechanism as are monohydric alcohols.

Kinetics and mechanism of the oxidation of formic acid bybis-(2,2′-bipyridyl) copper(II) permanganate

Abstract: The oxidation of formic acid bybis-(2,2′-bipyridyl)copper(II) permanganate (BBCP) is first order with respect to BBCP. The order with respect to formic acid is less than one in the absence of perchloric acid whereas in the presence of perchloric acid, it is more than one but less than two. Thus in both the cases Michaelis-Menten type kinetics were observed with respect to formic acid. The overall formation constants for the formic acid-BBCP complexes and their rates of decomposition have been evaluated. Thermodynamic parameters for complex formation and the activation parameters for their decomposition have also been calculated. The hydrogen-ion dependence has the formk obs=a+b[H+]+c[H+]2. The oxidation of deuterioformic acid showed the presence of a primary kinetic isotope effect (k H/k D≈4). An increase in the amount of acetic acid in the solvent mixture, acetic acid and water, increases the rate. The addition of 2,2′-bipyridine and acrylonitrile has no effect on the rate. Suitable mechanisms have been proposed.