Motion Planning for Shape–Controlled Adaptable Buildings Resembling Topologically Closed–Loop Robotic Systems

2012 ◽  
Author(s):  
Eftychios G. Christoforou ◽  
Andreas Müller ◽  
Marios C. Phocas
Keyword(s):  
Motion Planning ◽  
Shape Control ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Robotic Manipulators ◽  
Robotic Systems ◽  
Superior Performance ◽  
Building Structures ◽  
Singular Configurations ◽  
Shape Controlled

Shape–controlled adaptable building structures have a potential of superior performance and flexibility compared to traditional fixed–shape ones. A building concept is proposed consisting of a number of interconnected planar n–bar linkages performing coordinated motions thus resembling a system of cooperating closed–loop robotic manipulators. For shape control an “effective 4–bar” linkage concept is proposed. That is, each individual n–bar mechanism is equipped with one motion actuator, and at any time of motion its degrees–of–freedom are reduced to one through the selective locking of (n – 4) joints using brakes. Shape adjustments of the overall structure can be carried out through appropriate control sequences where in each step exactly four joints of each linkage are unlocked giving rise to an effective 4–bar system. Motion planning is considered together with the relevant limitations arising from singular configurations that need to be taken into account. The concept is demonstrated through simulation examples.

Towards Realization of Shape-Controlled Adaptable Buildings Following a Robotics Approach

2013 ◽  
Author(s):  
Eftychios G. Christoforou ◽  
Andreas Müller ◽  
Marios C. Phocas ◽  
Maria Matheou ◽  
Socrates Arnos
Keyword(s):  
Closed Loop ◽  
Superior Performance ◽  
Building Structures ◽  
Prior Work ◽  
Flexible Material ◽  
Closed Chain ◽  
Parallel Arrangement ◽  
Shape Controlled ◽  
Skeleton Structure ◽  
Control Sequences

Shape–controlled adaptable buildings constitute a major excursion from traditional architectural approaches with a potential for superior performance and enhanced flexibility compared to traditional fixed–shape building structures. A building concept is examined whose skeleton structure consists of a parallel arrangement of planar closed–loop n–bar linkages and it is covered with a flexible material. Shape adjustments involve coordinated reconfigurations of the constituent closed–chain mechanisms. Each individual linkage is equipped with one motion actuator as well as brakes installed on every joint. For the reconfigurations an “effective 4–bar” concept has been proposed that involves stepwise adjustments. Each step involves the selective locking of (n – 4) joints of each linkage so that it is effectively reduced to a single–DOF 4–bar mechanism the configuration of which can be adjusted using the available motion actuator. Appropriately planned control sequences can be used for a complete reconfiguration of the linkage. Motion planning is concerned with the generation of optimal control sequences while taking into account imposed limitations arising from the moving structure as well as the flexible envelop. This paper is a continuation of a prior work paying special attention to the envelop design. Simulation examples as well as an experimental study are used to demonstrate the feasibility of the concept and investigate relevant issues.

A Compact 3 Degree of Freedom Spherical Joint

2011 ◽  
Vol 3 (3) ◽  
Author(s):  
Mark L. Guckert ◽  
Michael D. Naish
Keyword(s):  
Control Systems ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Degree Of Freedom ◽  
Robotic Systems ◽  
Closed Loop Control ◽  
Spherical Joint ◽  
Experimental Assessment ◽  
Loop Control ◽  
Robotic Applications

Spherical joints have evolved into a critical component of many robotic systems, often used to provide dexterity at the wrist of a manipulator. In this work, a novel 3 degree of freedom spherical joint is proposed, actuated by tendons that run along the surface of the sphere. The joint is mechanically simple and avoids mechanical singularities. The kinematics and mechanics of the joint are modeled and used to develop both open- and closed-loop control systems. Simulated and experimental assessment of the joint performance demonstrates that it can be successfully controlled in 3 degrees of freedom. It is expected that the joint will be a useful option in the development of emerging robotic applications, particularly those requiring miniaturization.

scholarly journals Design and Motion Planning of a Biped Climbing Robot with Redundant Manipulator

2019 ◽  
Vol 9 (15) ◽  
pp. 3009 ◽  
Author(s):  
Qing Chang ◽  
Xiao Luo ◽  
Zhixia Qiao ◽  
Qian Li
Keyword(s):  
Motion Planning ◽  
Degrees Of Freedom ◽  
System Development ◽  
Robotic Systems ◽  
Climbing Robot ◽  
Redundant Manipulator ◽  
Railway Bridges ◽  
Planning Algorithm ◽  
Inspection Tasks ◽  
Maintenance And Inspection

A novel robot capable of performing maintenance and inspection tasks for railway bridges is proposed in this paper. Termed CMBOT (climbing manipulator robot), the robot is a combination of a five-degrees-of-freedom (5-Dof) biped climbing robot with two electromagnetic feet and a redundant manipulator with 7-Dof. This capability offers important advantages for performing maintenance and inspection tasks for railway bridges. Several fundamental issues of the CMBOT, such as robotic system development and motion planning algorithms, are addressed in this paper. A series of simulations and prototype experiments were conducted to validate the proposed robotic systems and motion planning algorithm. The results of the experiments show the reliability of the robotic systems and the efficiency of the motion planning algorithm.

Kinematic Analysis and Optimization of a Novel Robot for Surgical Tool Manipulation

2008 ◽  
Author(s):  
Xiaoli Zhang ◽  
Carl A. Nelson
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Force Feedback ◽  
Robotic Systems ◽  
Small Space ◽  
Surgical Robots ◽  
Tool Positioning ◽  
Rotation Axes ◽  
Surgical Tool ◽  
Linear Nature

The size and limited dexterity of current surgical robotic systems are factors which limit their usefulness. To improve the level of assimilation of surgical robots in minimally invasive surgery (MIS), a compact, lightweight surgical robotic positioning mechanism with four degrees of freedom (DOF) (three rotational DOF and one translation DOF) is proposed in this paper. This spatial mechanism based on a bevel-gear wrist is remotely driven with three rotation axes intersecting at a remote rotation center (the MIS entry port). Forward and inverse kinematics are derived, and these are used for optimizing the mechanism structure given workspace requirements. By evaluating different spherical geared configurations with various link angles and pitch angles, an optimal design is achieved which performs surgical tool positioning throughout the desired kinematic workspace while occupying a small space bounded by a hemisphere of radius 13.7 cm. This optimized workspace conservatively accounts for collision avoidance between patient and robot or internally between the robot links. This resultant mechanism is highly compact and yet has the dexterity to cover the extended workspace typically required in telesurgery. It can also be used for tool tracking and skills assessment. Due to the linear nature of the gearing relationships, it may also be well suited for implementing force feedback for telesurgery.

scholarly journals Software Sensor to Enhance Online Parametric Identification for Nonlinear Closed-Loop Systems for Robotic Applications

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3653
Author(s):  
Lilia Sidhom ◽  
Ines Chihi ◽  
Ernest Nlandu Kamavuako
Keyword(s):  
Degrees Of Freedom ◽  
Closed Loop ◽  
Sliding Mode ◽  
Robot Manipulator ◽  
Parametric Identification ◽  
Recursive Least Squares ◽  
Unknown Parameters ◽  
Closed Loop Identification ◽  
Input Variables ◽  
Robotic Applications

This paper proposes an online direct closed-loop identification method based on a new dynamic sliding mode technique for robotic applications. The estimated parameters are obtained by minimizing the prediction error with respect to the vector of unknown parameters. The estimation step requires knowledge of the actual input and output of the system, as well as the successive estimate of the output derivatives. Therefore, a special robust differentiator based on higher-order sliding modes with a dynamic gain is defined. A proof of convergence is given for the robust differentiator. The dynamic parameters are estimated using the recursive least squares algorithm by the solution of a system model that is obtained from sampled positions along the closed-loop trajectory. An experimental validation is given for a 2 Degrees Of Freedom (2-DOF) robot manipulator, where direct and cross-validations are carried out. A comparative analysis is detailed to evaluate the algorithm’s effectiveness and reliability. Its performance is demonstrated by a better-quality torque prediction compared to other differentiators recently proposed in the literature. The experimental results highlight that the differentiator design strongly influences the online parametric identification and, thus, the prediction of system input variables.

New repetitive motion planning scheme with cube end-effector planning precision for redundant robotic manipulators

Robotica ◽  
2021 ◽  
pp. 1-22
Author(s):  
Limin Shen ◽  
Yuanmei Wen
Keyword(s):  
Theoretical Analysis ◽  
Motion Planning ◽  
Robotic Manipulators ◽  
Robotic Manipulator ◽  
Repetitive Motion ◽  
End Effector ◽  
Difference Formula ◽  
Planning Scheme ◽  
Simulation Results ◽  
The Difference

Abstract Repetitive motion planning (RMP) is important in operating redundant robotic manipulators. In this paper, a new RMP scheme that is based on the pseudoinverse formulation is proposed for redundant robotic manipulators. Such a scheme is derived from the discretization of an existing RMP scheme by utilizing the difference formula. Then, theoretical analysis and results are presented to show the characteristic of the proposed RMP scheme. That is, this scheme possesses the characteristic of cube pattern in the end-effector planning precision. The proposed RMP scheme is further extended and studied for redundant robotic manipulators under joint constraint. Based on a four-link robotic manipulator, simulation results substantiate the effectiveness and superiority of the proposed RMP scheme and its extended one.

An Analytical Method for Locating Velocity Instantaneous Centers

1992 ◽  
Author(s):  
Hong-Sen Yan ◽  
Meng-Hui Hsu
Keyword(s):  
Analytical Method ◽  
Degrees Of Freedom ◽  
Coefficient Matrix ◽  
Multiple Degrees Of Freedom ◽  
Singular Configurations ◽  
Special Cases

Abstract An analytical method is presented for locating all velocity instantaneous centers of linkage mechanisms with single or multiple degrees of freedom. The method is based on the fact that the coefficient matrix of the derived velocity equations for vector loops, independent inputs, and instantaneous centers is singular. This approach also works for special cases with kinematic indeterminacy or singular configurations.

Kinematics Analysis and Motion Control of a Mobile Robot Driven by Three Tracked Vehicles

2018 ◽  
Author(s):  
Xin-Jun Liu ◽  
Zhao Gong ◽  
Fugui Xie ◽  
Shuzhan Shentu
Keyword(s):  
Mobile Robot ◽  
Motion Planning ◽  
Degrees Of Freedom ◽  
Inverse Kinematic ◽  
Planning Method ◽  
Tracked Vehicles ◽  
Loop Control ◽  
Point Motion ◽  
Point To Point ◽  
Motion Mode

In this paper, a mobile robot named VicRoB with 6 degrees of freedom (DOFs) driven by three tracked vehicles is designed and analyzed. The robot employs a 3-PPSR parallel configuration. The scheme of the mechanism and the inverse kinematic solution are given. A path planning method of a single tracked vehicle and a coordinated motion planning of three tracked vehicles are proposed. The mechanical structure and the electrical architecture of VicRoB prototype are illustrated. VicRoB can achieve the point-to-point motion mode and the continuous motion mode with employing the motion planning method. The orientation precision of VicRoB is measured in a series of motion experiments, which verifies the feasibility of the motion planning method. This work provides a kinematic basis for the orientation closed loop control of VicRoB whether it works on flat or rough road.

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