Task-Based Configuration Management for Modular Serial Robotic Manipulators

Author(s):  
Oziel Rios ◽  
Ganesh Krishnamoorthy ◽  
Aaron Hulse ◽  
Lucas Koran ◽  
Benjamin Gully ◽  
...  

Modular robotic systems have become popular in recent years due to the ease of reconfigurability to satisfy varying task requirements. Due to the nonlinear nature of the actuator performance parameters, it is often difficult to map component specifications to the overall system performance making it cumbersome to use these parameters to design the system. Specifying system requirements based on task specifications, on the other hand, provides greater insight into how the system must perform in order to complete a given task and the resources required to achieve this performance. In this paper, we present a method for optimal design of modular robotic manipulators using a finite set of actuators to execute various tasks. Three different tasks — material removal, welding and a pick-and-place operation — which have different requirements in terms of the force, speed, precision and energy required to perform them, are considered. A set of five actuators is used to form different serial robotic manipulator configurations whose ability to accomplish the task is then evaluated using various performance metrics. A sequential filtering method is used to eliminate infeasible manipulator configurations and the remaining feasible set of manipulator configurations are then optimized using the weighted sum and compromise multiobjective optimization methods to determine a Pareto optimal manipulator configuration to accomplish each of the three tasks individually, in addition to a fourth manipulator configuration that is capable of accomplishing all the three tasks.

2021 ◽  
Vol 11 (11) ◽  
pp. 4982
Author(s):  
Anahita Davoodi ◽  
Peter Johansson ◽  
Myriam Aries

Validation of the EBD-SIM (evidence-based design-simulation) framework, a conceptual framework developed to integrate the use of lighting simulation in the EBD process, suggested that EBD’s post-occupancy evaluation (POE) should be conducted more frequently. A follow-up field study was designed for subjective–objective results implementation in the EBD process using lighting simulation tools. In this real-time case study, the visual comfort of the occupants was evaluated. The visual comfort analysis data were collected via simulations and questionnaires for subjective visual comfort perceptions. The follow-up study, conducted in June, confirmed the results of the original study, conducted in October, but additionally found correlations with annual performance metrics. This study shows that, at least for the variables related to daylight, a POE needs to be conducted at different times of the year to obtain a more comprehensive insight into the users’ perception of the lit environment.


Author(s):  
Yeo Jung Yoon ◽  
Oswin G. Almeida ◽  
Aniruddha V. Shembekar ◽  
Satyandra K. Gupta

Abstract By attaching a material extrusion system to a robotic arm, we can deposit materials onto complex surfaces. Robotic manipulators can also maximize the task utility by performing other tasks such as assembly or surface polishing when they are not in use for the AM process. We present a robotic cell for embedding prefabricated components in extrusion-based AM. The robotic cell consists of two 6 degrees of freedom (DOF) robots, an extrusion system, and a gripper. One robot is used for printing a part, and the other robot takes a support role to pick and place the prefabricated component and embed it into the part being printed. After the component is embedded, AM process resumes, and the material is deposited onto the prefabricated components and previously printed layers. We illustrate the capabilities of the system by fabricating three objects.


2021 ◽  
pp. 411-418
Author(s):  
Aditya Mathur ◽  
Chetan Bansal ◽  
Sandeep Chauhan ◽  
Omprakash Yadav

2020 ◽  
pp. 241-259
Author(s):  
Robert Prey

This chapter explores the implications of performance metrics as a source of self-knowledge and self-presentation. It does so through the figure of the contemporary musician. As performers on-stage and online, musicians are constantly assessed and evaluated by industry actors, peers, music fans, and themselves. The impact of powerful modes of quantification on personal experiences, understandings, and practices of artistic creation provides insight into the wider role that metrics play in shaping how we see ourselves and others; and how we present ourselves to others. Through in-depth interviews with emerging musicians, this chapter thus uses the artist as a lens through which to understand everyday life within the “performance complex.”


2020 ◽  
Vol 10 (3) ◽  
pp. 1-16
Author(s):  
Sanjay P. Ahuja ◽  
Emily Czarnecki ◽  
Sean Willison

Cloud computing has rapidly become a viable competitor to on-premise infrastructure from both management and cost perspectives. This research provides insight into cluster computing performance and variability in cloud-provisioned infrastructure from two popular public cloud providers. A comparative examination of the two cloud platforms using synthetic benchmarks is provided. In this article, we compared the performance of Amazon Web Services Elastic Compute Cluster (EC2) to the Google Cloud Platform (GCP) Compute Engine using three benchmarks: STREAM, IOR, and NPB-EP. Experiments were conducted on clusters with increasing nodes from one to eight. We also performed experiments over the course of two weeks where benchmarks were run at similar times. The benchmarks provided performance metrics for bandwidth (STREAM), read and write performance (IOR), and operations per second (NPB-EP). We found that EC2 outperformed GCP for bandwidth. Both provided good scalability and reliability for bandwidth with GCP showing a slight deviation during the two-week trial. GCP outperformed EC2 in both the read and write tests (IOR) as well as the operations per second test. However, GCP was extremely variable during the read and write tests over the two-week trial. Overall, each platform excelled in different benchmarks and we found EC2 to be more reliable in general.


Author(s):  
Zhe Qin ◽  
Xiao-Chu Liu ◽  
Zhuan Zhao

A three-degree-of-freedom Delta parallel manipulator driven by a crank-slider mechanism is proposed. In Cartesian space, a gate-shaped curve is taken as the path of the pick-and-place operation, combining with the inverse kinematics theory of the Delta robot, and a mathematical model of robot statia force transmission is established. The force and the output torque of the robot-driven joint are taken as the main performance indexes, and the value of the crank-slider mechanism applied to Delta robot is further measured. The simulation results show that the delta robot driven by the crank slider mechanism can reduce the force and output torque of the driving joint during the picking and discharging operation, and has good practical application value.


Author(s):  
Oziel Rios ◽  
Delbert Tesar

A serial robotic manipulator arm is a complex electro-mechanical system whose performance is highly characterized by its actuators. The actuator itself is a complex nonlinear system whose performance can be represented by the speed and torque capabilities of its motor and its accuracy depends on the resolution of the encoder as well as its ability to resist deformations under load. The mechanical gain associated with the transmission is critical to the overall performance of the actuator since it amplifies the motor torque thus improving the force capability of the manipulator housing it, reduces the motor speed to a suitable output speed operating range, enables an improvement in responsiveness (acceleration) and amplifies the stiffness improving the precision under load of the overall system. In this work, a basic analytic process that can be used to manage the actuator gain parameters to obtain an improved arm design based on a set of desired/required performance specifications will be laid out. Key to this analytic process is the mapping of the actuator parameters (speed, torque, stiffness and encoder resolution) to their effective values at the system output via the mechanical gains of the actuators as well as the effective mechanical gains of the manipulator. This forward mapping of the actuator parameters allows the designer to determine how each of the parameters influences the functional capacity of the serial manipulator arm. The actuator gains are then distributed along the effective length of the manipulator to determine the distribution effects on the performance capabilities of the system. The analytic formulation is used to address the issue of configuration management of serial robotic manipulators where the goal is to assemble a system from a finite set of components that meets some required performance specifications. To this end, two examples demonstrating a solution of the configuration management problem are presented. In the first, a manipulator is configured that is intended for light-duty applications while in the second, several manipulators intended for medium and heavy-duty applications are configured. The analytic process developed in this work can reduce the effort in the initial phases of the design process and the total number of design iterations can be reduced.


Author(s):  
Zexiao Xie ◽  
Peixin Wu ◽  
Ping Ren

A comparative study on the pick-and-place trajectories for high-speed Delta robots is presented in this paper. The Adept Cycle has been widely accepted as a standardized pick-and-place trajectory for industrial robots. The blending curves and optimization methods to smooth this trajectory are briefly surveyed. Three major types of trajectories: Lamé curves, clothoids and piecewise polynomials, are selected as candidates to be compared. The processes to generate these trajectories are briefly reviewed. The trajectories are firstly compared in term of their computation time. Then, based on a dynamic model and an experimental prototype of the Delta robot, different combinations of the geometric paths and motion profiles are compared in terms of power consumption, terminal state accuracy and residual vibration. The effects of trajectory configurations and parameters on the robot’s dynamic performances are investigated. Through a comprehensive analysis on both simulation and experimental results, a near-optimal pick-and-place trajectory for the Delta robot is identified and validated.


Author(s):  
Shaoping Bai ◽  
Lasse Køgs Andersen ◽  
Carsten Rebbe Mølgaard

This work deals with the design of parallel robots for the generation of pick-and-place operation, or Schönflies motion. The aim is to develop a robot with workspace optimized for fast pick-and-place operations, namely, a robot with a superellipsoidal reachable volume, which suits best for the pick-and-place operations on conveyers, where robots’ working areas are nearly rectangular. In this paper, the kinematics and stiffness modeling of the new robot are presented. A method of stiffness modeling by means of Castigliano’s Theorem is developed. Using the new method, the stiffness of the robot is analyzed. The results are compared with FEA simulation, which shows a good agreement between the results. The method is finally applied to the engineering design of the new robot for enhanced static and dynamic performance.


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