Iuliu Negrean

Formulations about Dynamics of Mobile Robots

In this paper the dynamics equations for a mobile robot, named PatrolBot, will be developed, using new concepts in advanced mechanics, based on important scientific researches of the main author, concerning the kinetic energy. In keeping the fact that the mathematical models of the mobile platforms are different besides the other robots types, due to nonholonomic constraints, these dynamic control functions, will be computed, according to these restrictions for robot motion.

Dynamics of Hybrid Robot Structures Using Variational Principles

The purpose of this paper is to determine the dynamic equations for a hybrid robot structure which consists of a mobile robot named PatrolBot and a 2TR robot serial structure. The motion equations will be determined on the basis of the new concepts in advanced mechanics, such as Matrix Exponentials Algorithm and Variation Principles in Analytical Mechanics, concerning the kinetic and acceleration energy part of important scientific researches deployed by the main author.

New Formulations on Acceleration Energy in the Robot Dynamics

Based on formulations developed in this paper, a few important notions in the dynamics of robot mechanical systems are analyzed. Using some differential transformations as well as matrix exponentials the expressions for acceleration energy will be determined, in an explicit form and then in matrix form. The expressions for acceleration energy will lead into determining control functions for any mechanical robot structure (MRS).

New formulations about dynamics of robots

On the basis of new formulations within of this paper, a few important notions and theorems in the dynamics of the mechanical systems, in which the robots are included, will be analyzed. In the view of this, at beginning, the generalized variation law of the inertial and pseudo-inertial tensor will be presented in a new formulation. Using a few differential transformations, as well as matrix exponentials, in the following the kinetic and then acceleration energy will be presented. On the basis of these notions, a few formulations about the fundamentals theorems in the dynamics of the mechanical systems will be also dignified. All these stay at the basis of the generalized dynamics forces (control functions) for the mechanical robot structures.

Study about the dynamics of a translational robot axis based on ball screw transmission

The paper is focused on a detailed dynamic study for an axis belonging to a serial robot structure. It contains an analytical study for the driving moments for a translational robot axis based on ball screw transmission. The study of transmission gearing, and implicit a rigorous determination of the driving moments, along the cinematic chain of the mechanical robotic system is a fundamental aspect, with deep implications in optimal robot design in terms of sizing, power consumption and accuracy.

Demolding Moment Calculation for Injected Parts with Internal Trapezoidal Thread

At the final step of the injection process (of a plastic product with cavities) when the part is on the point to be ejected the adhesion phenomena occurs between the core and the plastic part. The mold adhesion effect has a significant influence on the mold design ejection system and over the whole process. This paper presents a computation methodology of the demolding moment for two cases of plastic injected parts with internal trapezoidal thread. Knowing the value of this moment offer us the possibility to adopt the right design solution of the ejector system and of the entire mold. As further work the author will try to validate this method through a set of practical experiments.

New Formulations on Motion Equations in Analytical Dynamics

Using the main authors researches on the energies of acceleration and higher order equations of motion, this paper is devoted to new formulations in analytical dynamics of mechanical multibody systems (MBS). Integral parts of these systems are the mechanical robot structures, serial, parallel or mobile on which an application will be presented in order to highlight the importance of the differential motion equations in dynamics behavior. When the components of multibody mechanical systems or in its entirety presents rapid movements or is in transitory motion, are developed higher order variations in respect to time of linear and angular accelerations. According to research of the main author, they are integrated into higher order energies and these in differential equations of motion in higher order, which will lead to variations in time of generalized forces which dominate these types of mechanical systems. The establishing of these differential equations of motion, it is based on a generalization of a principle of analytical differential mechanics, known as the D`Alembert – Lagrange Principle.

New Formulations on Acceleration Energies in Analytical Dynamics

This paper presents new formulations on the higher order motion energies that are applied in the dynamic study of multibody mechanical systems in keeping with the researches of the main author. The analysis performed in this paper highlights the importance of motion energies of higher order in the study of dynamic behavior of fast moving mechanical systems, as well as in transient phase of motion. In these situations, are developed higher order time variations of the linear and angular accelerations. As a result, in the final part of this paper is presented an application that emphasizes this essential dynamic aspect regarding the higher order acceleration energies.

Energies of Accelerations in Advanced Robotics Dynamics

This paper is devoted to the presentation of new formulations on the higher order motion energies that are used in the advanced dynamic study of robots. Integral part of these mechanical systems are the mechanical robot structures, on which an application will be presented in order to highlight the importance of the higher order motion energies regarding the dynamic behavior. In current dynamic studies, the kinetic energy is used as a central function in Lagrange - Euler equations. This paper extends the study by developing the acceleration energies of first, second and third order and their implementation in differential equations of motion of third and fourth order, which gives the possibility of applying the initial motion conditions in positions, velocities and accelerations of first and second order. This leads to a more precise control on the transitory motion phases of the multibody systems, in which the robot structures are included.

Formulations in Advanced Dynamics of Mechanical Systems

In the paper, in keeping with the fact that the robots are complex mechanical systems, on the basis of matrix exponentials, some notions applicable in advanced dynamics of mechanical systems, as well as variational principle from analytical mechanics will be analyzed. There will be presented the D’Alembert-Lagrange principle, written in the generalized form, and a few formulations on the Hamilton’s variational principle. On the basis of these aspects, by using of important mass distribution parameters, there will be expressed the kinetic energy and first and second order of the acceleration energy, the last one into a new formulation.