scholarly journals A Novel Kinematic Directional Index for Industrial Serial Manipulators

2020 ◽  
Vol 10 (17) ◽  
pp. 5953 ◽  
Author(s):  
Giovanni Boschetti
Keyword(s):  
Degrees Of Freedom ◽  
Experimental Tests ◽  
Maximum Speed ◽  
Robot Arm ◽  
Serial Manipulators ◽  
Six Degrees Of Freedom ◽  
Serial Robot ◽  
Novel Method ◽  
Points Of View ◽  
Articulated Robot

In the last forty years, performance evaluations have been conducted to evaluate the behavior of industrial manipulators throughout the workspace. The information gathered from these evaluations describes the performances of robots from different points of view. In this paper, a novel method is proposed for evaluating the maximum speed that a serial robot can reach with respect to both the position of the robot and its direction of motion. This approach, called Kinematic Directional Index (KDI), was applied to a Selective Compliance Assembly Robot Arm (SCARA) robot and an articulated robot with six degrees of freedom to outline their performances. The results of the experimental tests performed on these manipulators prove the effectiveness of the proposed index.

Compensation of geometric and elastic errors in large manipulators with an application to a high accuracy medical system

Robotica ◽  
2002 ◽  
Vol 20 (3) ◽  
pp. 341-352 ◽  
Author(s):  
Ph. Drouet ◽  
S. Dubowsky ◽  
S. Zeghloul ◽  
C. Mavroidis
Keyword(s):  
Degrees Of Freedom ◽  
High Accuracy ◽  
Medical Robot ◽  
Serial Manipulators ◽  
High Position ◽  
Six Degrees Of Freedom ◽  
Position Accuracy ◽  
End Point ◽  
Compensation Process ◽  
Very High

A method is presented that compensates for manipulator end-point errors in order to achieve very high position accuracy. The measured end-point error is decomposed into generalized geometric and elastic error parameters that are used in an analytical model to calibrate the system as a function of its configuration and the task loads, including any payload weight. The method exploits the fundamental mechanics of serial manipulators to yield a non-iterative compensation process that only requires the identification of parameters that are function only of one variable. The resulting method is computationally simple and requires far less measured data than might be expected. The method is applied to a six degrees-of-freedom (DOF) medical robot that positions patients for cancer proton therapy to enable it to achieve very high accuracy. Experimental results show the effectiveness of the method.

scholarly journals Trueness of full-arch IO scans estimated based on 3D translational and rotational deviations of single teeth—an in vitro study

2021 ◽  
Author(s):  
Johanna Radeke ◽  
Annike B. Vogel ◽  
Falko Schmidt ◽  
Fatih Kilic ◽  
Stefan Repky ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
In Vitro Study ◽  
Confocal Laser ◽  
Anterior Crowding ◽  
Six Degrees Of Freedom ◽  
Staff Members ◽  
Total Displacement ◽  
Dental Staff ◽  
Novel Method

Abstract Objectives To three-dimensionally evaluate deviations of full-arch intraoral (IO) scans from reference desktop scans in terms of translations and rotations of individual teeth and different types of (mal)occlusion. Materials and methods Three resin model pairs reflecting different tooth (mal)positions were mounted in the phantom head of a dental simulation unit and scanned by three dentists and three non-graduate investigators using a confocal laser IO scanner (Trios 3®). The tooth-crown surfaces of the IO scans and reference scans were superimposed by means of best-fit alignment. A novel method comprising the measurement of individual tooth positions was used to determine the deviations of each tooth in the six degrees of freedom, i.e., in terms of 3D translation and rotation. Deviations between IO and reference scans, among tooth-(mal)position models, and between dentists and non-graduate investigators were analyzed using linear mixed-effects models. Results The overall translational deviations of individual teeth on the IO scans were 76, 32, and 58 µm in the lingual, mesial, and intrusive directions, respectively, resulting in a total displacement of 114 µm. Corresponding rotational deviations were 0.58° buccal tipping, 0.04° mesial tipping, and 0.14° distorotation leading to a combined rotation of 0.78°. These deviations were the smallest for the dental arches with anterior crowding, followed by those with spacing and those with good alignment (p < 0.05). Results were independent of the operator’s level of education. Conclusions Compared to reference desktop scans, individual teeth on full-arch IO scans showed high trueness with total translational and rotational deviations < 115 µm and < 0.80°, respectively. Clinical relevance Available confocal laser IO scanners appear sufficiently accurate for diagnostic and therapeutic orthodontic applications. Results indicate that full-arch IO scanning can be delegated to non-graduate dental staff members.

scholarly journals KINEMATICS ANALYSIS AND IMPLEMENTATION OF THREE DEGREES OF FREEDOM ROBOTIC ARM BY USING MATLAB

2021 ◽  
Vol 21 (2) ◽  
pp. 118-129
Author(s):  
Hasan Dawood Salman ◽  
Mohsin Noori Hamzah ◽  
Sadeq Hussein Bakhy
Keyword(s):  
Interface Design ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Algebraic Solution ◽  
Robot Arm ◽  
Kinematics Modeling ◽  
Arduino Microcontroller ◽  
Articulated Robot ◽  
Forward Kinematic ◽  
Three Degree Of Freedom

The kinematics modeling of the robot arm plays an important role in robot control. This paper presents the kinematic model of a three-degree of freedom articulated robot arm, which is designed for picking and placing an application with hand gripper, where a robot has been manufactured for that purpose. The forward kinematic model has been presented in order to determine the end effector’s poses using the Denavit-Hartenberg (DH) convention. For inverse kinematics, an algebraic solution based on trigonometric formulas mixed with geometric method was adopted for a 3 DOF modular manipulator taking into account the existence of a shoulder offset. MATLAB software was used as a tool to simulate and implement the motional characteristics of the robot arm, by creating a 3D visual software package under designing a Graphical User Interface "GUI" with a support simulation from robotic Toolbox (Rtb 10.3). Finally, an electronic interfacing circuit between the GUI program and the robot arm was developed using Arduino microcontroller to control the robot motion. The presented work can be applicable for learning the reality interface design methodology of the other kinds of robot manipulators and achieve a suitable solution for the motional characteristics

scholarly journals Energy Optimization of Functionally Redundant Robots through Motion Design

2020 ◽  
Vol 10 (9) ◽  
pp. 3022
Author(s):  
Paolo Boscariol ◽  
Roberto Caracciolo ◽  
Dario Richiedei ◽  
Alberto Trevisani
Keyword(s):  
Energy Efficiency ◽  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Energy Savings ◽  
Robot Arm ◽  
Redundant Robots ◽  
Performance Metric ◽  
Serial Robot ◽  
Motion Profile ◽  
Motion Design

This work proposes to exploit functional redundancy as a tool to enhance the energy efficiency of a robotic system. In a functionally redundant system, i.e., one in which the number of degrees of freedom required to complete the task is smaller than the number of available degrees of freedom, the motion of the extra degrees of freedom can be tailored to enhance a performance metric. This work showcases a method that can be used to effectively enhance the energy efficiency through motion design, using a detailed dynamic model of the UR5 serial robot arm. The method is based on an optimization of the motion profile, using a parametrized description of the end-effector orientation: the results showcase an increased efficiency that allows energy savings up to 20.8%, according to the energy consumption results according to the electro-mechanical dynamic model of the robot.

Design and Modeling of an Experimental ROV with Six Degrees of Freedom

Drones ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 113
Author(s):  
Aleksey Kabanov ◽  
Vadim Kramar ◽  
Igor Ermakov
Keyword(s):  
Mathematical Model ◽  
Degrees Of Freedom ◽  
Experimental Tests ◽  
Underwater Vehicles ◽  
Six Degrees Of Freedom ◽  
Functional Capabilities ◽  
Classical Design ◽  
Wide Range ◽  
Reduced Costs ◽  
The Mathematical Model

With the development of underwater technology, it is important to develop a wide range of autonomous and remotely operated underwater vehicles for various tasks. Depending on the problem that needs to be solved, vehicles will have different designs and dimensions, while the issues surrounding reduced costs and increasing the functionality of vehicles are relevant. This article discusses the development of inspection class experimental remotely operated vehicles (ROVs) for performing coastal underwater inspection operations, with a smaller number of thrusters, but having the same functional capabilities in terms of controllability (as vehicles with traditionally-shaped layouts). The proposed design provides controllability of the vehicle in six degrees of freedom, using six thrusters. In classical design vehicles, such controllability is usually achieved using eight thrusters. The proposed design of the ROV is described; the mathematical model, the results of modeling, and experimental tests of the developed ROVs are shown.

The Wide-Open Three-Legged Parallel Robot for Long-Bone Fracture Reduction

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Mohammad H. Abedinnasab ◽  
Farzam Farahmand ◽  
Jaime Gallardo-Alvarado
Keyword(s):  
Bone Fracture ◽  
Degrees Of Freedom ◽  
Experimental Tests ◽  
Parallel Robot ◽  
High Accuracy ◽  
Fracture Reduction ◽  
Long Bone ◽  
Long Bones ◽  
Six Degrees Of Freedom ◽  
Long Bone Fracture

Robotic reduction of long bones is associated with the need for considerable force and high precision. To balance the accuracy, payload, and workspace, we have designed a new six degrees-of-freedom three-legged wide-open robotic system for long-bone fracture reduction. Thanks to the low number of legs and their nonsymmetrical configuration, the mechanism enjoys a unique architecture with a frontally open half-plane. This facilitates positioning the leg inside the mechanism and provides a large workspace for surgical maneuvers, as shown and compared to the well-known Gough–Stewart platform. The experimental tests on a phantom reveal that the mechanism is well capable of applying the desired reduction steps against the large muscular payloads with high accuracy.

Kinematic model to control the end-effector of a continuum robot for multi-axis processing

Robotica ◽  
2015 ◽  
Vol 35 (1) ◽  
pp. 224-240 ◽  
Author(s):  
Salvador Cobos-Guzman ◽  
David Palmer ◽  
Dragos Axinte
Keyword(s):  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Euler Angle ◽  
Inverse Kinematic ◽  
End Effector ◽  
Six Degrees Of Freedom ◽  
Hazardous Environments ◽  
Continuum Robot ◽  
Novel Method ◽  
Six Dof

SUMMARYThis paper presents a novel kinematic approach for controlling the end-effector of a continuum robot for in-situ repair/inspection in restricted and hazardous environments. Forward and inverse kinematic (IK) models have been developed to control the last segment of the continuum robot for performing multi-axis processing tasks using the last six Degrees of Freedom (DoF). The forward kinematics (FK) is proposed using a combination of Euler angle representation and homogeneous matrices. Due to the redundancy of the system, different constraints are proposed to solve the IK for different cases; therefore, the IK model is solved for bending and direction angles between (−π/2 to +π/2) radians. In addition, a novel method to calculate the Jacobian matrix is proposed for this type of hyper-redundant kinematics. The error between the results calculated using the proposed Jacobian algorithm and using the partial derivative equations of the FK map (with respect to linear and angular velocity) is evaluated. The error between the two models is found to be insignificant, thus, the Jacobian is validated as a method of calculating the IK for six DoF.

scholarly journals Kinematic Analysis of 6 DOF Articulated Robotic Arm

2021 ◽  
pp. 1-5
Author(s):  
Aravinthkumar T ◽  
Suresh M ◽  
Vinod B
Keyword(s):  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Material Handling ◽  
Manufacturing Sector ◽  
Industrial Robot ◽  
Research Work ◽  
Industrial Robots ◽  
Robot Arm ◽  
Articulated Robot ◽  
Increasing Demand

The abstract must be a precise and reflection of what is in your article. Manufacturing sector is moving towards industry 4.0 and demands a high end of automation in the process. In which industrial robots play a fundamental role for automating the processes such as pick and place, material handling, palletizing, welding, painting, assembly lines and many more endless applications. Increasing demand and necessity made more research on industrial robots, machine learning and artificial intelligence. Better kinematic analysis of robots leads to reliable, high precise and fast responsive system. But there is an absence of India based robot manufacturers to fulfil the rising demand. Again, this situation leads to a market for foreign robot makers instead of local players. Lack of knowledge in robotics, unavailability of robot parts and resources are pain points for this cause. As researchers in this domain and have a goal to resolve this issue by providing open source, easily accessible industrial robot technical resources to everyone. This research work focuses the design and development of 6 Degrees of Freedom articulated robot arm with kinematic analysis particularly forward and inverse kinematics.

Trajectory Prediction with a Conditional Variational Autoencoder

2019 ◽  
Vol 31 (3) ◽  
pp. 493-499
Author(s):  
Thibault Barbié ◽  
◽  
Takaki Nishio ◽  
Takeshi Nishida
Keyword(s):  
Motion Planning ◽  
Degrees Of Freedom ◽  
Industrial Robot ◽  
Computation Time ◽  
Prediction Algorithm ◽  
Robot Arm ◽  
Trajectory Prediction ◽  
Six Degrees Of Freedom ◽  
Variational Autoencoder ◽  
Planning Approaches

Conventional motion planners do not rely on previous experience when presented with a new problem. Trajectory prediction algorithms solve this problem using a pre-existing dataset at runtime. We propose instead using a conditional variational autoencoder (CVAE) to learn the distribution of the motion dataset and hence to generate trajectories for use as priors within the traditional motion planning approaches. We demonstrate, through simulations and by using an industrial robot arm with six degrees of freedom, that our trajectory prediction algorithm generates more collision-free trajectories compared to the linear initialization, and reduces the computation time of optimization-based planners.

Sign in / Sign up

Export Citation Format

Share Document