Design of an Underactuated Robotic End-Effector With a Focus on Power Tool Manipulation

2014 ◽  
Author(s):  
Michael Rouleau ◽  
Dennis Hong
Keyword(s):  
Disaster Response ◽  
Degrees Of Freedom ◽  
Humanoid Robot ◽  
Servo Motor ◽  
End Effector ◽  
Design Considerations ◽  
Wide Range ◽  
End Effectors ◽  
Four Bar Linkage ◽  
Careful Design

End-effectors require careful design considerations to be able to successfully hold and use power tools while maintaining the ability to also grasp a wide range of other objects. This paper describes the design of an end effector for a humanoid robot built for disaster response scenarios. The end effector is comprised of two independently actuated fingers with two opposing stationary rigid hollow pylons built to allow the pinching of objects and to provide protection for the opposing fingers when retracted and not in use. Each finger has two degrees of freedom (DOF) and is actuated with one servo motor through the use of an underactuated four bar linkage. Using only two fingers and two actuators the end-effector has the ability to hold a power tool while also being able to simultaneously actuate the trigger of the tool independently. The combination of compliant fingers and rigid pylons along with the careful design of the palm structure creates a strong robust dexterous end-effort that is simple to control.

Analysis and Validation of a Flexible Planar Two Degrees-of-Freedom Parallel Manipulator With Structural Passive Compliance

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Genliang Chen ◽  
Zhuang Zhang ◽  
Lingyu Kong ◽  
Hao Wang
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Interaction Force ◽  
Flexible Manipulator ◽  
End Effector ◽  
Flexible Links ◽  
Wide Range ◽  
Pick And Place ◽  
Passive Compliance ◽  
Large Deflection Problem

Abstract Passive compliance plays an important role in robot pick-and-place manipulation where large interaction force will be produced in response to small misalignments. In this paper, the authors report on compliance analysis and validation of a novel planar pick-and-place parallel manipulator consisting of a flexible limb. In the proposed manipulator, a planar flexible parallelogram linkage, which is coupled with a rigid one, is introduced to connect the moving and the base platforms. Since the flexible parallelogram linkage is capable of producing large deformation in both the horizontal and the vertical directions, the end effector of the manipulator can generate wide-range motions because of the flexible links. An efficient approach to the large deflection problem of flexible links is used to precisely predict the kinetostatics of the manipulator. Then, a compensation algorithm to the structural deflection of the links can be developed to actively control the position of the parallel manipulator’s end effector. The merit of the proposed flexible manipulator is its intrinsic passive compliance while performing pick-and-place tasks. A prototype is fabricated to conduct experiments for the validation of the proposed idea. The results show that the prototype has acceptable positioning accuracy, even when a large external load is exerted on its end effector. The compliance properties of the proposed flexible manipulator have also been verified in both the horizontal and the vertical directions.

scholarly journals ONLINE LEARNING OF THE BODY SCHEMA

2008 ◽  
Vol 05 (02) ◽  
pp. 161-181 ◽  
Author(s):  
MICHA HERSCH ◽  
ERIC SAUSER ◽  
AUDE BILLARD
Keyword(s):  
Online Learning ◽  
Degrees Of Freedom ◽  
Humanoid Robot ◽  
Body Schema ◽  
The Body ◽  
Space Representation ◽  
Real Robot ◽  
Sensorimotor Contingencies ◽  
End Effectors ◽  
Subjective Space

We present an algorithm enabling a humanoid robot to visually learn its body schema, knowing only the number of degrees of freedom in each limb. By "body schema" we mean the joint positions and orientations and thus the kinematic function. The learning is performed by visually observing its end-effectors when moving them. With simulations involving a body schema of more than 20 degrees of freedom, results show that the system is scalable to a high number of degrees of freedom. Real robot experiments confirm the practicality of our approach. Our results illustrate how subjective space representation can develop as a result of sensorimotor contingencies.

Coordinated Visual and Kinematic Servoing for Positioning Manipulating UAV End-Effectors

2014 ◽  
Author(s):  
Todd W. Danko ◽  
Paul Y. Oh
Keyword(s):  
Disaster Response ◽  
Degrees Of Freedom ◽  
Joint Space ◽  
Degree Of Freedom ◽  
Ground Vehicles ◽  
Manipulator Arm ◽  
One Step ◽  
Infrastructure Repair ◽  
End Effectors ◽  
Six Degree Of Freedom

Manipulating objects using arms mounted to unmanned aerial vehicles (UAVs) is attractive because UAVs may access many locations that are otherwise inaccessible to traditional mobile manipulation platforms such as ground vehicles. However, the constantly moving UAV platform and compliance of manipulator arms make it difficult to position the UAV and end-effector relative to an object of interest precisely enough for reliable manipulation. Solving this challenge will bring UAVs one step closer to being able to perform meaningful tasks such as infrastructure repair, disaster response, law enforcement, and personal assistance. Toward a solution to this challenge, this paper describes an approach to coordinate the redundant degrees of freedom of a six degree of freedom gantry with those of a six degree of freedom manipulator arm. The manipulator’s degrees of freedom are visually servoed to a specified pose relative to a target while treating motions of the host platform as perturbations. Simultaneously, the host platform’s degrees of freedom are servoed using kinematic information from the manipulator. This drives the base of the manipulator to a position that allows it to assume a joint-space configuration that maximizes reachability while minimizing static torque transmitted from the arm to the host.

Development of a Reconfigurable End-Effector Prototype

2017 ◽  
Author(s):  
Frank Khelfa ◽  
Lukas Zimmer ◽  
Paul Motzki ◽  
Stefan Seelecke
Keyword(s):  
Degrees Of Freedom ◽  
Material Handling ◽  
Exchange Process ◽  
End Effector ◽  
Locking Mechanism ◽  
Different Shapes ◽  
End Effectors ◽  
Future Work ◽  
Crucial Part

Material handling is a crucial part of manufacturing and assembly in industry. In state-of-the-art handling systems, robots use various end-effectors to grip and transport different shapes of workpieces. The exchange process of fitted end-effectors to appropriate workpieces, often requires to interrupt the manufacturing process. From the prospective of economic efficiency, there is an inherent benefit creating a reconfigurable end-effector that is able to adjust automatically to different workpiece geometries. In this work a novel end-effector prototype based on shape memory alloys (SMA’s) is developed and experimentally validated. The end-effector prototype has four arms with two SMA driven reconfigurable degrees of freedom (DOF’s) to allow gripping of different workpiece shapes and geometries. Each arm is rotatable by 90 degrees (1. DOF) and uses a counterweight to relieve the SMA wire. The tip of the arm is driven by a separate SMA in a 20 degree range and it has a special locking mechanism to hold different positions without any flowing current. The designs of the actuator constructions are presented and a prototype is produced via rapid-prototyping. Future work will include the characterization of the second DOF and controlling the positions of both DOF’s by using a PID controller based on the SMA self-sensing ability.

Design, testing and evaluation of an end-effector for self-relocation

Robotica ◽  
2015 ◽  
Vol 34 (12) ◽  
pp. 2689-2728 ◽  
Author(s):  
Feng Han ◽  
Kui Sun ◽  
Yu Liu ◽  
Hong Liu
Keyword(s):  
Degrees Of Freedom ◽  
Physical Simulation ◽  
Industrial Robot ◽  
Space Environment ◽  
Air Bearing ◽  
End Effector ◽  
Six Degrees Of Freedom ◽  
Soft Capture ◽  
End Effectors ◽  
Prototype Design

SUMMARYTwo identical end-effectors are indispensable for self-relocation of a space manipulator, which is an effective way of extending its servicing capability. The prototype design is intimately linked to the requirements. The significant features and functionality of the end-effector and its grapple fixture are described, including the key analysis efforts. The characteristics of the end-effector and their suitability for self-relocation and payload handling were confirmed by testing, which used two prototype end-effectors, a semi-physical simulation testbed system with two, six degrees of freedom (DOF) industrial robot arms, and an air-bearing testbed system with a seven DOF manipulator. The results demonstrate that the end-effector satisfies the requirements and it can work well in a simulated space environment. With the compliance motion of the manipulator, the end-effector can perform soft capture and the manipulator can securely self-relocate and handle the payload.

Design of a Human-Like Range of Motion Hip Joint for Humanoid Robots

2014 ◽  
Author(s):  
Bryce Lee ◽  
Coleman Knabe ◽  
Viktor Orekhov ◽  
Dennis Hong
Keyword(s):  
Range Of Motion ◽  
Hip Joint ◽  
Disaster Response ◽  
Degrees Of Freedom ◽  
Humanoid Robot ◽  
Large Range ◽  
Humanoid Robots ◽  
Linkage Mechanism ◽  
Joint Torques ◽  
Similar Range

For a humanoid robot to have the versatility of humans, it needs to have similar motion capabilities. This paper presents the design of the hip joint of the Tactical Hazardous Operations Robot (THOR), which was created to perform disaster response duties in human-structured environments. The lower body of THOR was designed to have a similar range of motion to the average human. To accommodate the large range of motion requirements of the hip, it was divided into a parallel-actuated universal joint and a linkage-driven pin joint. The yaw and roll degrees of freedom are driven cooperatively by a pair of parallel series elastic linear actuators to provide high joint torques and low leg inertia. In yaw, the left hip can produce a peak of 115.02 [Nm] of torque with a range of motion of −20° to 45°. In roll, it can produce a peak of 174.72 [Nm] of torque with a range of motion of −30° to 45°. The pitch degree of freedom uses a Hoeken’s linkage mechanism to produce 100 [Nm] of torque with a range of motion of −120° to 30°.

The QuadroG Robot, a Parallel Robot With a Configurable Platform for Haptic Applications

2015 ◽  
Author(s):  
Salua Hamaza ◽  
Patrice Lambert ◽  
Marco Carricato ◽  
Just Herder
Keyword(s):  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Parallel Robot ◽  
Parallel Robots ◽  
End Effector ◽  
Contact Points ◽  
Loop Chain ◽  
End Effectors ◽  
4 Degrees Of Freedom

This paper explores the fundamentals of parallel robots with configurable platforms (PRCP), as well as the design and the kinematic analysis of those. The concept behind PRCP is that the rigid (non-configurable) end-effector is replaced by a closed-loop chain, the configurable platform. The use of a closed-loop chain allows the robot to interact with the environment from multiple contact points on the platform, which reflects the presence of multiple end-effectors. This results in a robot that successfully combines motion and grasping capabilities into a structure that provides an inherent high stiffness. This paper aims to introduce the QuadroG robot, a 4 degrees of freedom PRCP which finely merges planar motion together with grasping capabilities.

scholarly journals Sistem Pick and Place Dua Derajat Kebebasan menggunakan Metoda Regresi

2019 ◽  
Vol 7 (3) ◽  
pp. 521
Author(s):  
ERWANI MERRY SARTIKA ◽  
RUDI SARJONO ◽  
HAZEL XARIS CHRISOPHRAS
Keyword(s):  
Degrees Of Freedom ◽  
Industrial Robot ◽  
Regression Method ◽  
Robot Design ◽  
Servo Motor ◽  
End Effector ◽  
Two Degrees Of Freedom ◽  
Pick And Place ◽  
The Relationship

ABSTRAKSistem pick and place merupakan suatu sistem mekanik yang digunakan untuk memanipulasi pergerakan mengangkat, memindahkan, dan meletakkan untuk meringankan kerja manusia. Dalam mempelajari cara kerja robot industri sederhana dibuat miniatur robot pick and place (sederhana). Perancangan yang dibuat yaitu sistem pick and place dengan dua derajat kebebasan dengan ukuran yang memiliki perbandingan 1:0.35 dari referensi ukuran desain robot. Aplikasi SolidWorks digunakan untuk mendesain robot Diamond. Metode Regresi digunakan untuk memprediksi posisi motor servo dalam mencapai posisi yang diinginkan. Metode regresi berhasil digunakan untuk mencari hubungan antara target posisi setpoint dengan posisi motor servo 1 dan 2 (persamaan orde 2 dan 3) untuk mengontrol motor servo. Performansi yang terbaik dari sistem pick and place yang dibuat menggunakan trayektori miring, dengan kecepatan 100 (11.1 rpm), menghasilkan error ± 0.0729 dan presisi 1.63%. Dalam penelitian ini, kecepatan end-effector yang lebih rendah menghasilkan keakurasian dan kepresisian yang lebih baik.Kata kunci: Pick and Place, Robot Diamond, Dua derajat kebebasan, Regresi ABSTRACTThe pick and place system are a mechanic system used in manipulating the movements of lifting, moving, and laying to ease human work. In learning how to work a simple industrial robot, a miniature pick and place robot is created. The design made is a pick and place system with two degrees of freedom with a size that has a ratio of 1: 0.35 from the reference size of the robot design. Regression method is used to predict the position of the servo motor in reaching the desired position. Regression method was successfully used to find the relationship between the target setpoint position and the position of servo motors 1 and 2 (order equations 2 and 3) to control the servo motor. The best performance from the pick and place system that is made using an aslope trajectory, with a speed of 100 (11.1 rpm), produces an error ± 0.0729 and precision 1.63%. In this research, lower end-effector speeds result in better accuracy and precision.Keywords: Pick and Place, Diamond Robot, 2-DOF, Regression

On the Solution of Region-Based Planar Six-Bar Motion Generation for Four Finitely Separated Position

2012 ◽  
Author(s):  
Jianyou Han ◽  
Tong Yang
Keyword(s):  
Local Solution ◽  
Synthesis Problem ◽  
Motion Generation ◽  
End Effector ◽  
Numerical Example ◽  
Region Method ◽  
Solution Region ◽  
End Effectors ◽  
Four Bar Linkage ◽  
The Way

This paper addresses the synthesis problem of Watt-I and Stephenson-IIIa six-bar linkages motion generation for four specified task positions. Both of them have one thing in common — theirs floating links which used as end-effectors are connected to a coupler plane of a four-bar linkage. Once the task positions of end-effector are given, we can calculate the corresponding positions of the coupler plane. Then our focus is on the synthesis of a four bar-linkage and the way that a RR chain can be attached to constrain the links of this four-bar linkage. This synthesis problem of four-bar linkage motion generation can be settled by a solution region method. And then we can present an equation of pivot curve that each point on this curve can generate a satisfactory RR chain. A new local solution region that is more practicable is presented by the last numerical example.

scholarly journals Development of a humanoid robot hand with coupling four-bar linkage

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668631 ◽  
Author(s):  
Xinhua Liu ◽  
Xianhua Zheng ◽  
Shengpeng Li
Keyword(s):  
Humanoid Robot ◽  
Three Dimensional ◽  
Human Hand ◽  
Robot Hand ◽  
End Effector ◽  
Kinematics Simulation ◽  
Contact Kinematics ◽  
Motion Range ◽  
Four Bar Linkage ◽  
The Mathematical Model

To improve the operating performance of robots’ end-effector, a humanoid robot hand based on coupling four-bar linkage was designed. An improved transmission system was proposed for the base joint of the thumb. Thus, a far greater motion range and more reasonable layout of the palm were obtained. Moreover, the mathematical model for kinematics simulation was presented based on the Assur linkage group theory to verify and optimize the proposed structure. To research the motion relationships between the fingers and the object in the process of grasping object, the grasping analysis of multi-finger manipulation was presented based on contact kinematics. Finally, a prototype of the humanoid robot hand was produced by a three-dimensional printer, and a kinematics simulation example and the workspace solving of the humanoid robot hand were carried out. The results showed that the velocities of finger joints approximately met the proportion relationship 1:1:1, which accorded with the grasping law of the human hand. In addition, the large workspace, reasonable layout, and good manipulability of the humanoid robot hand were verified.

Sign in / Sign up

Export Citation Format

Share Document