Method for analytical description and modeling of the working space of a manipulation robot

This paper reports a method, built in the form of a logic function, for describing the working spaces of manipulation robots analytically. A working space is defined as a work area or reachable area by a manipulation robot. An example of describing the working space of a manipulation robot with seven rotational degrees of mobility has been considered. Technological processes in robotic industries can be associated with the positioning of the grip, at the required points, in the predefined coordinates, or with the execution of the movement of a working body along the predefined trajectories, which can also be determined using the required points in the predefined coordinates. A necessary condition for a manipulation robot to execute a specified process is that all the required positioning points should be within a working space. To solve this task, a method is proposed that involves the analysis of the kinematic scheme of a manipulation robot in order to acquire a graphic image of the working space to identify boundary surfaces, as well as identify additional surfaces. The working space is limited by a set of boundary surfaces where additional surfaces are needed to highlight parts of the working space. Specifying each surface as a logic function, the working space is described piece by piece. Next, the resulting parts are combined with a logical expression, which is a disjunctive normal form of logic functions, which is an analytical description of the working space. The correspondence of the obtained analytical description to the original graphic image of working space is verified by simulating the disjunctive normal form of logic functions using MATLAB (USA).

Hybrid Decentralized Nonlinear Control System for Manipulation Robot with Input Saturations

The paper is devoted to consideration of the problem of constructing a discrete-continuous decentralized nonlinear combined control system for two-link robotic manipulator with restrictions in control signals. The mathematical model of the manipulator is presented as a two-channel dynamic plant with nonlinear cross-links. As methods for solving this problem V. M. Popov’s hyperstability criterion and the conditions of L-dissipativity are used. With the help of simulation, the quality of the proposed control system is shown. The results obtained in article may be useful for construction the control systems for manipulators with many degrees of freedom and also for control various mechanical systems.

Installation of Clip-Type Bird Flight Diverters on High-Voltage Power Lines with Aerial Manipulation Robot: Prototype and Testbed Experimentation

This work presents the application of an aerial manipulation robot for the semi-autonomous installation of clip-type bird flight diverters on overhead power line cables. A custom-made prototype is designed, developed, and experimentally validated. The proposed solution aims to reduce the cost and risk of current procedures carried out by human operators deployed on suspended carts, lifts, or manned helicopters. The system consists of an unmanned aerial vehicle (UAV) equipped with a custom-made tool. This tool allows the high force required for the diverter installation to be generated; however, it is isolated from the aerial robot through a passive joint. Thus, the aerial robot stability is not compromised during the installation. This paper thoroughly describes the designed prototype and the control system for semi-autonomous operation. Flight experiments conducted in an illustrative scenario validate the performance of the system; the tests were carried out in an indoor testbed using a power line cable mock-up.

Impulse control of a two-link manipulation robot

A nonlinear problem of controlling the movements of a two-link manipulation robot is considered. The free mechanical system has two first integrals in involution. Methods of classical mechanics are used for analytical integration of the system of nonlinear differential equations. A trajectory connecting the initial and final positions of the two-link manipulation robot in the configuration space is found. Impulse controls at the initial moment of time impart the necessary energy to the robot to enter this trajectory. Impulse controls are also used to damp the speeds of the robot at the end position. In a computer simulation of the proposed procedure for moving the robot, generalized impulse controls are approximated by rectangular impulses.

Offline Direct Teaching for a Robotic Manipulator in the Computational Space

This paper proposes a robot teaching method using augmented and virtual reality technologies. Robot teaching is essential for robots to accomplish several tasks in industrial production. Although there are various approaches to perform motion planning for robot manipulation, robot teaching is still required for precision and reliability. Online teaching, in which a physical robot moves in the real space to obtain the desired motion, is widely performed because of its ease and reliability. However, actual robot movements are required. In contrast, offline teaching can be accomplished entirely in the computational space, and it requires constructing the robot’s surroundings as computer graphic models. Additionally, planar displays do not provide sufficient information on 3D scenes. Our proposed method can be employed as offline teaching, but the operator can manipulate the robot intuitively using a head-mounted device and the specified controllers in the virtual 3D space. We demonstrate two approaches for robot teaching with augmented and virtual reality technologies and show some experimental results.