Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Mechanical Models in Design: Kinematics and Dynamics

In course

ME-311: Dynamical effects in mechanical design

Ce cours poursuit la compréhension des effets cinématiques et dynamiques de systèmes mécaniques complexes et introduit les bases pour les comprendre et les modéliser. L'étudiant saura expliquer et modéliser la dynamique et choisir des modèles adéquats. ...

Description

This lecture introduces different types of models in mechanical design, including static, kinematic, and dynamic models. It covers topics such as inertia forces, deformable elements, harmonic excitation, and the reduction of complex systems. The instructor explains the limitations of the kinematic model, the influence of flexibility on structural efforts, and the importance of energy conservation in reducing movement. The lecture also delves into the analysis of oscillations, parametric vibrations, and the amplification factor in dynamic systems. Additionally, it discusses the transmission of forces, dynamic errors, and the behavior of non-uniform mechanisms. Practical design considerations, such as balancing rotors, critical speeds, and the reduction of effort transmission, are also addressed.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Instructor

Jürg Alexander Schiffmann

After obtaining his diploma in mechanical engineering from EPFL in 1999 he co-founded a start-up company dedicated to the design of gas bearing supported rotors. In 2005 he joined Fischer Engineering Solutions where he led the development of small-scale, gas bearing supported high-speed turbomachinery for fuel cell air supplies and for domestic scale heat pumps. In parallel he worked on his PhD, which he obtained from EPFL in 2008 and for which he was awarded the SwissElectric Research Award. He then joined the Gas Turbine Lab at MIT as a postdoctoral associate where he worked on foil bearings and on the experimental investigation of radial diffusers. In 2013 he was nominated assistant professor at the Ecole Polytechnique Fédérale de Lausanne where he founds the Laboratory for Applied Mechanical Design. His current research interest are in gas lubricated bearings, in aerodynamics of small-scale compressors and turbines and in automated design and optimization methodologies.

Official source

Ontological neighbourhood

Physics

Mechanics: Classical mechanics

Mechanical engineering

Robotics: Topics in robotics

Related concepts (32)

Kinematics

Kinematics is a subfield of physics, developed in classical mechanics, that describes the motion of points, bodies (objects), and systems of bodies (groups of objects) without considering the forces that cause them to move. Kinematics, as a field of study, is often referred to as the "geometry of motion" and is occasionally seen as a branch of mathematics. A kinematics problem begins by describing the geometry of the system and declaring the initial conditions of any known values of position, velocity and/or acceleration of points within the system.

Inertia

Inertia is the idea that an object will continue its current motion until some force causes its speed or direction to change. The term is properly understood as shorthand for "the principle of inertia" as described by Newton in his first law of motion. After some other definitions, Newton states in his first law of motion: LAW I. Every object perseveres in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed thereon.

Inverse kinematics

In computer animation and robotics, inverse kinematics is the mathematical process of calculating the variable joint parameters needed to place the end of a kinematic chain, such as a robot manipulator or animation character's skeleton, in a given position and orientation relative to the start of the chain. Given joint parameters, the position and orientation of the chain's end, e.g. the hand of the character or robot, can typically be calculated directly using multiple applications of trigonometric formulas, a process known as forward kinematics.

Robot kinematics

In robotics, robot kinematics applies geometry to the study of the movement of multi-degree of freedom kinematic chains that form the structure of robotic systems. The emphasis on geometry means that the links of the robot are modeled as rigid bodies and its joints are assumed to provide pure rotation or translation. Robot kinematics studies the relationship between the dimensions and connectivity of kinematic chains and the position, velocity and acceleration of each of the links in the robotic system, in order to plan and control movement and to compute actuator forces and torques.

Moment of inertia

The moment of inertia, otherwise known as the mass moment of inertia, angular mass, second moment of mass, or most accurately, rotational inertia, of a rigid body is a quantity that determines the torque needed for a desired angular acceleration about a rotational axis, akin to how mass determines the force needed for a desired acceleration. It depends on the body's mass distribution and the axis chosen, with larger moments requiring more torque to change the body's rate of rotation.

Related lectures (35)

Mechanics: Moments and Rotations

Covers the calculation of total forces moments and the concept of rigid bodies.

Dynamics of Mechanisms: Theoretical Aspects and Applications

Discusses the dynamics of mechanisms, focusing on theoretical principles and practical applications in robotics.

Gravitation and Energy: Effective Potential

Covers gravitational force, energy conservation, and effective potential energy in elliptical and parabolic paths.

Kinematics and Dynamics of Point Particle

Explores Newton's laws, inertia, forces, momentum conservation, and real-world applications in car and motorcycle races.

Introduction to Relativity