Bhanoday Reddy Vemula

Metamodel Based Design Automation: Applied on Multidisciplinary Design Optimization of Industrial Robots

Intricate and complex dependencies between multiple disciplines require iterative intensive optimization processes. To this end, multidisciplinary design optimization (MDO) has been established as ...

A design metric for safety assessment of industrial robot design suitable for power- and force-limited collaborative operation

This research presents a novel design metric based on maximum power flux density for the assessment of the severity of a transient physical contact between a robot manipulator and a human body region. Such incidental transient contact can occur in the course of a collaborative application of the power- and force-limiting type. The proposed metric is intended for the design and development of the robot manipulator as well as for the design of manufacturing applications. Such safety metric can also aid in controlling the robot’s speeds during manufacturing operations by carrying out rapid risk assessments of impending collisions that could arise due to the proximity to the human co-worker. Furthermore, this study contributes by expressing the physical impact between the robot and the human body region as a linear spring-damper model. The influence of the restitution coefficient and the elasticity of the human tissues on the contact duration and contact area during the collision is analysed. With the demonstrated analysis model, the dependence of the power flux density with respect to the robot’s effective mass, speed, and geometrical and damping coefficients during the human-industrial robot manipulator collision process is investigated.

A methodology for evaluating energy-efficiency of different robot structures

Evaluation of different robot structures is a difficult but relevant challenge. Providing tools and methods to allow robot designers or end-users to quantitatively compare robot structures is necessary because the variety of existing robot structures makes it hard to choose which one is the best suited for a specific task or for a new application process. This paper proposes a methodology for evaluating a set of two robot structures at a time in order to select the best structure among them for a new application process. As a proof of concept this method is applied to evaluate two anthropomorphic robot structures, one with and one without parallel linkage transmission. The evaluation is done on the basis of finding the best robot structure, which while fulfilling a set of processbased performance requirements (End-effector motion parameters) should demonstrate better energy efficiency characteristics for applicability in emerging application areas of green robotics.

A methodology for comparing the dynamic efficiency of different kinematic robot structures

This study proposes a methodology for comparing the dynamic effectiveness of two different kinematic structures based on actuator torque requirement criteria. The objective of this comparison is to find out what type of robot structure is best suited as a lightweight industrial robot in the conceptual design phase. As a proof of concept this method is applied to compare Serial and Parallelogram linkage anthropomorphic kinematic structures with respect to torque requirements. Several directions for future research are discussed to include additional comparison criteria and also to extend the application of the proposed method to compare two versions of same structure in the design phase of light weight industrial robots.

Structural synthesis of 3DOF articulated manipulators based on kinematic evaluation

In this study, serial and parallelogram linkage structures are evaluated and compared, on the basis of kinematic performance measures such as workspace and manipulability. Tradeoff relationships between workspace manipulability are established for both the structures, using the configuration of the arm lengths as a design variable. The structures are also analyzed on the basis of their manipulation ability in specific regions of their workspace, providing additional design criteria during the selection of the kinematic structure in the synthesis of industrial articulated robots.