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Prof. Belgaumkar Memorial Lecture

Compliant Mechanisms: Large Deformation Analysis and Control with Innovative Applications

Compliant mechanisms demonstrate numerous advantages including soft operation, low weight, reduced power consumption, high speeds, high durability, zero backlash, frictionless motion, superior repeatability and positioning precision, and maintenance-free silent operation. These advantages come hand-in-hand with several challenges pertaining to complex nonlinear dynamics and control and unconventional fabrication and assembly.

Research over several years at our laboratory attempted to overcome these challenges, opening pathways for their applications into several industrial automation and robotics systems. This talk presents an overview of several compliant mechanisms and innovative ideas around them developed and deployed by our group in industrial automation and robotic systems applications.

We will delve deeper into dynamic modelling and control development ideas in select cases. Key applications with several filed/granted patents include precision micro-milling, 3D microprinting, micro-needle printing, micro-N force UTM, scanning probe for CMM, digital torque sensor, multi-scale fractal-like and array geometry micro-fabrication exploiting fluid instabilities, leech-inspired robot, and more. All these systems have been developed completely in-house.

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Professor Ashok Midha Memorial Lecture

Precision Compliant Mechanisms

Compliant mechanisms have gained significant attention, not in the least by Prof. Ashok Midha’s Pseudo-Rigid Body Model (PRBM) which has boosted understanding and application of compliant mechanisms by linking this field to familiar linkage design methods. This talk will illustrate how high-demand situations such as in robotics and precision manufacturing equipment inspire further innovations in compliant mechanisms.

Examples of the extension of PRBM to spatial compliant mechanisms will be presented as well as an energy-based variant. In addition, various strategies to improve the performance of compliant mechanisms will be discussed, ranging from different forms of static balancing to torsion reinforcement. Finally, an outlook on future developments will be provided.

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Professor K. Lakshminarayana Memorial Lecture

Shape, Contact and KineMagics

In the study of rigid body mechanisms, we usually ignore the geometric details of the links and joints. This abstraction is advantageous in design conceptualisation and mathematical analysis. However, in the bottom-up modelling approach followed in conventional MCAD and MBD systems, special expertise is called for in defining the right kind and number of constraints.

This talk will expand on the idea that it is ultimately the geometry of the parts in contact that dictates both assembly (persistence relations) and kinematics (variable relations). The first part of the talk will focus on the meaningful contact among sets of analytical (geometric) features and characterise the associated kinematic features (lower pairs); this, in turn, leads to a drag-and-drop or simple click-a-zone-based fast assembly modelling process that can implicitly generate a kinematic model simultaneously.

To overcome the limitations of analytical features in contact, the second part of the talk will focus on the motion-space of smooth contacts. Using principal curvatures for the description of the local geometry of shapes in contact, the nature of the motion space is explored using screw theory with screw derivatives. It establishes that even in frictionless point contact scenarios, relative DoF may drop faster than the conventional view! The results are then used to explore form-closure of smooth bodies and mechanisms.