Ivan Virgala

Modeling of a snake-like robot rectilinear motion and requirements for its actuators

The paper deals with a rectilinear motion of a snake-like robot. At first the various kinds of friction models are discussed and then the mathematical model of rectilinear snake-like robot locomotion is established. Considering the isotropic Coulomb´s friction model the average velocity of N-mass system is derived. Further the average velocity dependence on the number of used masses N is described through the graph. From the equation of average velocity there is the optimal number of masses N established. In the paper there are two alternative sequences of motion considered and subsequently through the simulations they are compared to each other. Finally the requirements concerning the linear actuator between two masses are described.

Snake Robot Movement in the Pipe Using Concertina Locomotion

Inspection tasks of pipes or channels are part of the engineering practice. In the past there were investigated conventional approaches like wheeled-based mechanisms. This paper deals with unconventional approach - snake robot moving in the pipe. In the paper locomotion pattern of concertina is introduced and subsequently kinematic model of concertina locomotion is established. Main requirements and conditions of presented locomotion pattern are stated. Using software Matlab the kinematic model is simulated according designed locomotion pattern in order to verify the kinematic model. For experimental purposes the experimental snake robot – LocoSnake is used. Simulation and experiment are compared and evaluated.

Simplified model of the snake rectilinear motion

The paper deals with the analysis of the snake rectilinear motion and from both the biological and the engineering points of view. The bionics knowledge enables more detailed insight to the problematic of the snake locomotion applicable at the design of the robotic snakes. The paper shows the analysis of the simplified model of the snake performed for determination of both the kinematic parameters and the characteristics of the actuating units utilized with probable design project.

Miniature Mobile Bristled In-Pipe Machine

The in-pipe machine locomotes in the pipe on the principle of differential friction between the bristles and the pipe wall during the movement of the bristle forwards and backwards. These bristles are very important construction parts of the in-pipe machine. In order to define the locomotion of movement it is important to know the force situation on the bristles caused by its high deformation in the pipe. The determination of force situation brought us to a non-linear differential equation of the second order and determination of conditions for its solution. By this equation it is possible to describe the outline of large deformations of the construction part and to determine the forces affecting this part.

Simulation Model of Manipulator for Model Based Design

The subject of creation of simulation and mathematical models is nowadays more and more current and its application is in almost every aspect of life. The article deals with compiling a mathematical model of a pivoting arm using Lagrange equations of the second kind. Subsequently, the model will be created in the simulation program Matlab/Simulink. The simulation model will as well be assembled in the program Adams. The results of these simulations will be compared in the conclusion. This article presents a procedure for resolving a mechanical system from the beginning, from creation of a mathematical model through creation of a simulation model up to evaluation of the simulation results. This paper presents a procedure for resolving mechanical system from the beginning. Thus, it is done by creating a mathematical model through the creation of a simulation model to evaluate the results of the simulation. According to these simulations will produce a working model of the manipulator, which could be used for teaching purposes.

Algorithm for determining static characteristic on electromagnetic actuator for rectilinear locomotion structure of a snake-like robot

This work deals with the determination of static characteristics of electromagnetic actuator. Electromagnetic actuator is designed as drive for rectilinear locomotion structure parts of snake-like robot. Static characteristics are determined by the solving of a non-linear problem of the actuators magnetic circuit in a ferromagnetic cores particular positions and at the different fluxional rates of the coil. Static characteristics are represented by a L induction, magnetic force affecting ferromagnetic core Fm. For the calculation of the coil induction L is used the power of magnetic field. Magnetic field power is calculated by using Maxwell stress tensor and differential formula by a numeric derivation way.

Intelligent in-pipe machine adjustable to inner pipe diameter

The paper concerns to area of in-pipe locomotion. Traditional conceptions of in-pipe machines tend to wheels slipping or self-blocking. Several design stages of improved in-pipe machine are shown. Design of in-pipe machine coming from conception of computer controlled electromechanical device. Final design solution will be able to locomote inside pipe with variation of inner diameter in range from 100 to 200 mm with automatically adjustment to pipe diameter.

Simulation Analysis of Pneumatic Rubber Bellows for Segment of Hyper-Redundant Robotic Mechanism

The paper deals with a design and simulations of segment for hyper-redundant manipulator. In the paper 6-DOF manipulator segment, which consists of pneumatic and electromagnetic actuators, is designed. CAD model of the segment is introduced and basic parts are described. The basic motion is reached by pneumatic actuator which works through the rubber bellows and it utilizes their expansion properties. Main focus of the study besides segment design is analysis of rubber bellows. From this reason FEM analysis is done in software SolidWorks. In the conclusion the results are discussed.

Dynamic Analysis of the Two-Mass System to Imitate Rectilinear Motion of a Snake

Dynamic Analysis of the Two-Mass System to Imitate Rectilinear Motion of a Snake A few previous decades the researchers and the designers started to copy the animal motion to the mechanisms. The principal motivations of the snaky locomotion are the environments where the traditional machines are not applicable due their dimensions or shapes and where the accessories like the wheels or the legs fail. The paper deals with the dynamic analysis of the two-mass system imitating the snake rectilinear motion on the level surface. Within the research there were made various modifications of the system and through the simulation was verified the behavior of the kinematic parameters. Based on the mentioned displacements and the speeds depending on the time it is possible to determine the optimal parameters of examined dynamic system.

An inspection of pipe by snake robot

The article deals with development and application of snake robot for inspection pipes. The first step involves the introduction of a design of mechanical and electrical parts of the snake robot. Next, the analysis of the robot locomotion is introduced. For the curved pipe, potential field method is used. By this method, the system is able to generate path for the head and rear robot, linking the environment with obstacles, which are represented by the walls of the pipe. Subsequently, the solution of potential field method is used in inverse kinematic model, which respects tasks as obstacle avoidance, joint limit avoidance, and singularity avoidance. Mentioned approach is then tested on snake robot in provisional pipe with rectangular cross section. For this research, software Matlab (2013b) is used as the control system in cooperation with the control system of robot, which is based on microcontrollers. By experiments, it is shown that designed robot is able to pass through straight and also curved pipe.