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The methodology of manual high-voltage transmission-line inspection is a time-consuming process, and also it involves high risk. The safe and efficient methodology of autonomous robotic inspection is needed to avoid these kinds of problems involved in the manual inspection. One of the challenging steps in the development of power transmission-line inspection robot is the design of a mechanism for crossing tension towers through the jumper cables and also avoiding obstacles in the transmission lines with minimum consumption of energy. Positioning of the robot in the transmission line and crossing the jumper cable are also difficult. This paper tries to find a feasible solution for these challenging issues. A novel design of the robot mechanism, positioning of dual arm for intelligent crossing and trajectory planning of arm based on minimum energy are presented. Optimum goal position for holding is determined using fuzzy logic. Ten degrees of freedom dual arm of the inspection robot is used for transferring a gripper hook to the goal position in the jumper cable through an optimum cubic trajectory for transferring whole robot from straight cable to jumper cable. Optimum energy trajectory is determined using primal dual interior-point method. This paper also presents the design of proportional-integral-derivative controller with genetic algorithm tuning for crossing from straight transmission line to jumper cable. Simulation study of robot motion through straight transmission line and jumper cable is also presented using ADAMS.

Parallel Kinematic Machines (PKMs) are being widely used for precise applications to achieve complex motions and variable poses for the end effector tool. PKMs are found in medical, assembly and manufacturing industries where accuracy is necessary. It is often desired to have a compact and simple architecture for the robotic mechanism. In this paper, the kinematic and dynamic analysis of a novel 3-PRUS (P: prismatic joint, R: revolute joint, U: universal joint, S: spherical joint) parallel manipulator with a mobile platform having 6 Degree of Freedom (DoF) is explained. The kinematic equations for the proposed spatial parallel mechanism are formulated using the Modified Denavit-Hartenberg (DH) technique considering both active and passive joints. The kinematic equations are used to derive the Jacobian matrix of the mechanism to identify the singular points within the workspace. A Jacobian based stiffness analysis is done to understand the variations in stiffness for different poses of the mobile platform and further, it is used to decide trajectories for the end effector within the singularity free region. The analytical model of the robot dynamics is presented using the Euler-Lagrangian approach with Lagrangian multipliers to include the system constraints. The gravity and inertial forces of all links are considered in the mathematical model. The analytical results of the dynamic model are compared with ADAMS simulation results for a pre-defined trajectory of the end effector.

Vegetable oils are regarded as renewable energy for future generations due to its biodegradability, high thermal properties, and good lubricity. Some of the disadvantages of vegetable oil are high pour point, low oxidative stability, and limited viscosity range. In this paper, we evaluate and compare the rheological properties of rice bran oil (RBO) with various proportions of low-density polyethylene (LDPE) and ethyl vinyl acetate (EVA) separately. The thermal stability also has been tested in this paper. Both the polymers have different mode of improving the viscosity and LDPE is found to be a viscosity index booster. The percentage improvement in viscosity for various proportions of polymers has been evaluated at various temperatures. It is seen that LDPE is more suited for engine oil applications since the high temperature rheology is more important in the selection of these lubricants. The viscosity variation of biolubricant formulations with temperature were validated with Walther equation. The biodegradability of both the polymers was estimated and compared with a commercially available mineral oil. The addition of EVA and LDPE in RBO reduces the biodegradability to a smaller extent but it is better than commercially available mineral oil SAE20W40.