scholarly journals Structural Parameters and Working Range Estimation of Excavator Backhoe Mechanism

2019 ◽  
Vol 8 (2S10) ◽  
pp. 867-872
Keyword(s):  
Structural Parameters ◽  
Kinematic Model ◽  
Computer Algorithm ◽  
Joint Angles ◽  
Range Estimation ◽  
Kinematical Model ◽  
Physical Prototype ◽  
Solid Foundation ◽  
Forward Kinematic ◽  
Earthmoving Machines

Earthmoving machines like excavators and loaders characteristics such as productivity, weight, reliability depend on their backhoe mechanism. For that, the backhoe mechanism has to deliver the desired working range, digging forces and stability which are dependent on structural parameters like components length and joint angles. This paper describes the method of developing a backhoe mechanism for the desired working range which constitutes cutting heights and reaches by using structural parameters. This requires to develop forward kinematical model by considering the backhoe mechanism as a mechanical manipulator. A computer algorithm was developed, that uses the forward kinematic model, to estimate the working range. Also, a relationship is established between joint angles and cylinder lengths. Results of Virtual prototype, modeled and simulated in MSC ADAMS along with the testing results of BEML designed Physical prototype were used to validate the working range and structural parameters. This research provides a solid foundation for analyzing the effect of structural parameters on digging forces and stability.

A Model of the Human Spine: Forward and Inverse Kinematics

1992 ◽  
Author(s):  
Sunil Kumar Agrawal ◽  
Siyan Li ◽  
Glen Desmier
Keyword(s):  
Range Of Motion ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Joint Angles ◽  
Human Spine ◽  
Forward And Inverse Kinematics ◽  
Position And Orientation ◽  
Three Degrees Of Freedom ◽  
Adjacent Vertebra

Abstract The human spine is a sophisticated mechanism consisting of 24 vertebrae which are arranged in a series-chain between the pelvis and the skull. By careful articulation of these vertebrae, a human being achieves fine motion of the skull. The spine can be modeled as a series-chain with 24 rigid links, the vertebrae, where each vertebra has three degrees-of-freedom relative to an adjacent vertebra. From the studies in the literature, the vertebral geometry and the range of motion between adjacent vertebrae are well-known. The objectives of this paper are to present a kinematic model of the spine using the available data in the literature and an algorithm to compute the inter vertebral joint angles given the position and orientation of the skull. This algorithm is based on the observation that the backbone can be described analytically by a space curve which is used to find the joint solutions..

scholarly journals A Recursive Algorithm for the Forward Kinematic Analysis of Robotic Systems Using Euler Angles

Robotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Fernando Gonçalves ◽  
Tiago Ribeiro ◽  
António Fernando Ribeiro ◽  
Gil Lopes ◽  
Paulo Flores
Keyword(s):  
Recursive Algorithm ◽  
Kinematic Chain ◽  
Robotic Systems ◽  
Mobile Manipulator ◽  
Euler Angles ◽  
Joint Angles ◽  
Main Research ◽  
Kinematic Chains ◽  
Research Fields ◽  
Forward Kinematic

Forward kinematics is one of the main research fields in robotics, where the goal is to obtain the position of a robot’s end-effector from its joint parameters. This work presents a method for achieving this using a recursive algorithm that builds a 3D computational model from the configuration of a robotic system. The orientation of the robot’s links is determined from the joint angles using Euler Angles and rotation matrices. Kinematic links are modeled sequentially, the properties of each link are defined by its geometry, the geometry of its predecessor in the kinematic chain, and the configuration of the joint between them. This makes this method ideal for tackling serial kinematic chains. The proposed method is advantageous due to its theoretical increase in computational efficiency, ease of implementation, and simple interpretation of the geometric operations. This method is tested and validated by modeling a human-inspired robotic mobile manipulator (CHARMIE) in Python.

Development of a 3-DOF Tripedal Stick-Slip Microrobotic Mobile Platform for Unconstrained, Omnidirectional Sample Positioning

2018 ◽  
Author(s):  
Iman Adibnazari ◽  
William S. Nagel ◽  
Kam K. Leang
Keyword(s):  
Visual Servoing ◽  
Feedforward Control ◽  
Low Cost ◽  
Tracking Error ◽  
Kinematic Model ◽  
Open Loop ◽  
Step Cycle ◽  
Stick Slip ◽  
Slip Step ◽  
Forward Kinematic

This paper presents the development of a piezo-based three-degree-of-freedom (3-DOF), tripedal microrobotic platform that allows for unlimited travel with sub-micron precision over a planar surface. Compliant mechanical amplifiers are incorporated with each piezoelectric stack actuator to improve both the stroke and load-bearing capability of the platform. A forward kinematic model of the stage based on its tripedal leg architecture is derived for each stick-slip step cycle and inverted for feedforward control of the platform. A prototype is constructed using low-cost 3D-printing techniques. Experimental results demonstrate actuator stroke of 29.4 μm on average with a dominant resonance of approximately 860 Hz. Results demonstrate the stage tracks a 3 mm by 3 mm square trajectory in open loop. Feedback control through visual servoing is then simulated on a model that includes flexure dynamics, observed surface interactions, and camera sampling times, reducing the root-mean-square (RMS) tracking error by 90%. This control scheme is then implemented experimentally, resulting in 99% RMS position error reduction relative to when only feedforward control is used.

Workspace Analysis of a 6-DOF Installing-Calibrating Robot

2011 ◽  
Vol 422 ◽  
pp. 75-78 ◽  
Author(s):  
Zhi Jiang Xie ◽  
Cheng Li ◽  
Wei Ni ◽  
Nan Liu
Keyword(s):  
Structural Parameters ◽  
Joint Space ◽  
Coordinate Systems ◽  
Robot Trajectory ◽  
The Monte Carlo Method ◽  
Workspace Analysis ◽  
Time Calculation ◽  
Random Probability ◽  
Forward Kinematic ◽  
Kinematic Solution

According to the working characteristics and installment environments of modules，a compact 6-DOF installing-calibrating robot was designed. Coordinate systems of joints are set upand the forward kinematic solution are derived by using D-H methods. Using the Monte Carlo method based on random probability and MATLAB software simulation for the robot's structural parameters to the robot's workspace impact. According to joint space to the mapping workspace，robots have been the workspace. The research results have proved that the designed configuration can satisfy the needs of installment action，which will provide theoretical reference for the robot trajectory planning，dynamic analysis and online real-time calculation.

Leg kinematic analysis and prototype experiments of walking-operating multifunctional hexapod robot

2013 ◽  
Vol 228 (12) ◽  
pp. 2217-2232 ◽  
Author(s):  
Pan Yang ◽  
Feng Gao
Keyword(s):  
Kinematic Analysis ◽  
Kinematic Model ◽  
Form Solution ◽  
Spherical Joint ◽  
Universal Joint ◽  
Step Size ◽  
Work Space ◽  
Prismatic Joint ◽  
Forward Kinematic ◽  
Close Form

This paper presents kinematic analysis of a 3-degree of freedom parallel mechanism for hexapod walking-operating multifuctional robot. Each leg of the robot consists of three limbs: universal joint – prismatic joint chain (1-UP) and universal joint – prismatic joint – spherical joint chain (2-UPS) and at the end of the leg there is passive spherical joint to adjust to the uneven ground. In this paper, first the forward kinematic model is built and it shows that the model has close-form solution. Then the work space is discussed in which the robot feet trajectories can be projected. It can be shown that the current trajectories of the feet only take very small work space. After that force analysis is performed and the results show that the payload capability of the mechanism is very high. Experiments of the prototype show that the robot can walk easily with more than 150 kg loads while the step size is more than 0.5 m.

Workspace Analysis and Parameter Optimization of 3-DOF Parallel Mechanism

2013 ◽  
Vol 373-375 ◽  
pp. 2136-2142 ◽  
Author(s):  
Rui Fan ◽  
Huan Liu ◽  
Dan Wang
Keyword(s):  
Parameter Optimization ◽  
Parallel Mechanism ◽  
Structural Parameters ◽  
Kinematic Model ◽  
Inverse Kinematic ◽  
Search Method ◽  
Architecture Design ◽  
Original Volume ◽  
Workspace Analysis ◽  
The Relationship

A spatial 3-DOF translational parallel mechanism is analyzed. Its inverse kinematic model is established. The section view of the workspace of the parallel mechanism is presented via boundary search method under the defined constraints. Considering the workspace volume as the optimization object, the relationship between structural parameters and workspace volume is obtained and the structural parameters to be optimized are determined. Finally, the optimization configuration of the mechanism is obtained. The results show that the volume of the workspace increases 1.55 times as much as the original volume, which lay the foundation for the architecture design.

A Method for Real-Time Estimating Pose of Large Aircraft Component in Process of Pose Adjustment Based on the Unscented Kalman Filter

2012 ◽  
Vol 442 ◽  
pp. 251-255
Author(s):  
Zheng Ying
Keyword(s):  
Kalman Filter ◽  
Real Time ◽  
Unscented Kalman Filter ◽  
Kinematic Model ◽  
Estimation Method ◽  
Time Estimation ◽  
Measuring Point ◽  
Aircraft Component ◽  
Forward Kinematic ◽  
Large Aircraft

To estimate the pose of large aircraft component in pose adjustment quickly and accurately, a real-time estimation method based on Unscented Kalman filter (UKF) is proposed. Firstly, in the process of the aircraft component adjustment, a rough value of aircraft component’s pose is acquired by using forward kinematic model and the displacement of positioners on real time. Then, position of a measuring point fixed on aircraft component is obtained by a laser tracker. At last, UKF is employed to integrate the previous rough value and the measuring point position for evaluating the accurate pose of aircraft component. Numerical simulation results show that the presented method is achieved easily, calculated fast and high accurate.

The use of a forward kinematic model in the construction of balanced cross sections

Tectonics ◽  
1990 ◽  
Vol 9 (5) ◽  
pp. 1249-1262 ◽  
Author(s):  
Lionel Endignoux ◽  
Jean-Louis Mugnier
Keyword(s):  
Cross Sections ◽  
Kinematic Model ◽  
Forward Kinematic
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