Current Issue : April - June Volume : 2021 Issue Number : 2 Articles : 5 Articles
In complex smart grid, the power maintenance robot is important equipment to ensure the reliable operation of high-voltage lines and it is a useful exploration to realize high-quality power transmission. In view of the increasingly prominent contradiction between the robot single operation function and the diversification of power grid maintenance operations, additional with the robot weak autonomous operation and intelligent behavior ability, this paper proposes a new configuration of a reconfigurable power robot with terminal functions and its autonomous operation behavior control method for the three typical tasks which are the high-voltage transmission line insulators, drainage plates, and dampers maintenance. Through the analysis and planning of the robot operation behavior, the robot finite state machine (FSM) model in the three operation states has been established. Through the introduction of the state transfer function in the FSM, the automatic switching control between the robot key operation states can be realized, and the robot motion planning can be optimized. The movement and working flow of the robot improve the robot operation intelligence and operation efficiency. Based on this, the robot autonomous operation control system has been designed and the robot physical prototype has been developed for three maintenance tasks of insulators, drainage plates, and dampers. Finally, simulation experiments and field operation tests verify the effectiveness and engineering practicability of the proposed method. Compared with traditional manual control, the autonomous behavior control method can significantly improve the robot operational efficiency and operational intelligence. At the same time, the robot multitask function and autonomous behavior control under different tasks can be realized and the method has strong versatility for different task objects and different line environments. The research and its promotion have important theoretical significance and practical application value for the power system operation and maintenance integration management....
Robot-assisted retinal cannulation is an eye surgical procedure which can dissolve the obstruction by using robot to inject anticoagulant into occluded vessel. The current research on the critical parameters of cannulation for human is scarce because of the immature technology. Considering the influence of microneedle, this work investigated the effects of drug concentration, injection velocity, injection position, and size of clot on cannulation by theoretical analysis and finite element analysis. For finite element analysis, the multiphysics continuum model was established to demonstrate species transport and reaction which simulates the entire lytic process of the occlusive clot, and four cell zones were established to describe the generation of plasmin (PLS) with the addition of tissue-type plasminogen activator (tPA) and fibrinolysis of clot by importing subroutines into each cell zone under the conditions of constant clot size and variable size, respectively. The results imply that the most efficient value of tPA concentration is 50 nM, injection velocity is 60 mm/s for clot length of 0.1 mm, and the best position to insert the cannula is 0.5mm in front of the thrombus. For different clot lengths of 0.1mm to 0.6 mm, the optimal range of tPA concentration and injection velocity is from 20nM to 70nM and from 40 mm/s to 60 mm/s, respectively, and explores the reasonable injection position of 0.3mm to 0.5mm in front of clot in a vein of 100 μm. This conclusion can be used to perform robot-assisted cannulation surgery to improve fibrinolytic efficiency....
Considering the complexity of multidimension parameters and the mechanical performance of a 6-DOF robotic crusher, a multiobjective optimization function based on the transmission index and condition number is established. As an important operation in the screw theory, the reciprocal product between the transmission wrench screw of an actuator and the output twist screw of the mantle assembly is used to represent the instantaneous power. The expression of transmission index is derived according to the principle that constraint wrench screws apply no work to the mantle assembly. It can be used as a criterion to evaluate the transmission performance. Then, based on the Jacobian matrix, the equation of condition number is constructed which provides a criterion for evaluating kinematic accuracy. Finally, the workspace and singularity of the 6-DOF robotic crusher are analyzed to verify the rationality of the optimized variables. Theresults show that the optimized structure can completely crush the material in the workspace and effectively avoid singularity, which provides a basis for practical application....
To improve the training scheme of new engineering talents, a teaching reform method on training innovation-oriented talent in robot engineering is explored comprehensively. By making a deep analysis between the graduates trained by the current robotic technology courses in universities and the talents required for the construction of emerging engineering into consideration, a teaching reform strategy of “characteristic theory teaching, practical engineering teaching, diversified assessment” has been put forward in the paper....
To solve the contradiction between dynamic performance and steady-state performance of the robot system, a smooth-switching control strategy is proposed. By combining robot and motor model, the complete model of the robot driving system is established. The single-loop Feedback Linearization (FL) controller and Port-Controlled Hamiltonian (PCH) controller based on the complete model are derived to ensure the rapidity and stability of the system respectively. A smooth-switching function based on position error is designed. It can ensure the smooth-switching between two controllers and avoid the instability caused by switch-switching. The proposed algorithm can make the robot system have good dynamic and steady performance. Simulation and experiment results demonstrate the effectiveness of the smooth-switch control strategy....
Loading....