Simplified Motion Control of a Vehicle manipulator for the Coordinated Mobile Manipulation

This paper considers a resolved kinematic motion control approach for controlling a spatial serial manipulator arm that is mounted on a vehicle base. The end-effector’s motion of the manipulator is controlled by a novel kinematic control scheme, and the performance is compared with the well-known operational-space control scheme. The proposed control scheme aims to track the given operational-space (end-effector) motion trajectory with the help of resolved configuration-space motion without using the Jacobian matrix inverse or pseudo inverse. The experimental testing results show that the suggested control scheme is as close to the conventional operational-space kinematic control scheme

Nickel (II) Removal from Aqueous Solutions by Adsorption on Fly-ash.

The feasibility of Ni(II) removal from water was investigated by adsorption on fly-ash. The equilibrium data of Ni(II) removal thus obtained is well fitted to Langmuir equation. The mono layer adsorption capacity was calculated and found to be 0.293 mg-1 at 30C. The batch adsorption kinetics follows first order reaction and appears to be diffusion controlled. The values of mass transfer and pore diffusion coefficients were 1.14 X 10-5 cm S-I and 6.2 xlO -1l cm2 s-J respectively at 30C. The influence of initial nickel concentration, residence time, temperature and pH on metal adsorption process was studied, An increase in the solution temperature, pH and decrease in concentration favour the removal of nickel by fly-ash. The maximum adsorption of Ni(II) ions was noted at pH 7.0. The various thermodynamic parameters were calculated for the present system. The empirical model has been tested for the kinetics join(II) removal by adsorption on fly ash and the parameters for the continuous operation of the removal process were determined

Performance Investigations of an Improved Backstepping Operational space Position Tracking Control of a Mobile Manipulator

This article implies an improved backstepping control technique for the operational-space position tracking of a kinematically redundant mobile manipulator. The mobile manipulator thought-out for the analysis has a vehicle base with four mecanum wheels and a serial manipulator arm with three rotary actuated joints. The recommended motion controller provides a safeguard against the system dynamic variations owing to the parameter uncertainties, unmodelled system dynamics and unknown exterior disturbances. The Lyapunov’s direct method assists in designing and authenticating the system’s closed-loop stability and tracking ability of the suggested control strategy. The feasibility, effectiveness and robustness of the recommended controller are demonstrated and investigated numerically with the help of computer based simulations. The mathematical model used for the computer-based simulations is derived based on a real-time mobile manipulator and the derived model is further verified with an inbuilt gazebo model in a robot operating system (ROS) environment. In addition, the proposed scheme is verified on an in-house fabricated mobile manipulator system. Further, the recommended controller performance is correlated with the conventional backstepping control design in both computer-based simulations and in real-time experiments

Parameter estimation of the Bardeen-Kerr black hole in cloud of strings using shadow analysis

We consider the rotating generalization of the Bardeen black hole solution in the presence of cloud of strings (CoS). The parameter space for which the black hole horizon exists is determined. We also study the static limit surface and the ergo-region in the presence of the CoS parameter. We consider photon orbits and obtain the deformation of black hole shadows due to rotation for various values of CoS parameter. The shadow deformation is used to determine the black hole spin for different values of the black hole parameters.Comment: 15 pages, 5 figure

Shadows and Quasinormal modes of the Bardeen black hole in cloud of strings

We investigate the black hole (BH) solution of the Einstein's gravity coupled with non-linear electrodynamics (NED) source in the background of a cloud of strings. We analyze the horizon structure, regularity, and energy conditions of the obtained BH solution. The optical features of the BH are explored. The photon radius and shadows of the BH are obtained as a function of black hole parameters. We observe that the size of the shadow image is bigger than its horizon radius and photon sphere. We also study the Quasinormal modes (QNM) using WKB formula for this black hole. The dependence of shadow radius and QN modes on black hole parameters reflects that they are mimicker to each other.Comment: 15 pages, 3 figure