scholarly journals Optimizing Kinematic Modeling and Self-Collision Detection of a Mobile Manipulator Robot by Considering the Actual Physical Structure

2021 ◽  
Vol 11 (22) ◽  
pp. 10591
Author(s):  
Lijun Qiao ◽  
Luo Xiao ◽  
Qingsheng Luo ◽  
Minghao Li ◽  
Jianfeng Jiang

In this paper, an optimized kinematic modeling method to accurately describe the actual structure of a mobile manipulator robot with a manipulator similar to the universal robot (UR5) is developed, and an improved self-collision detection technology realized for improving the description accuracy of each component and reducing the time required for approximating the whole robot is introduced. As the primary foundation for trajectory tracking and automatic navigation, the kinematic modeling technology of the mobile manipulator has been the subject of much interest and research for many years. However, the kinematic model established by various methods is different from the actual physical model due to the fact that researchers have mainly focused on the relationship between driving joints and the end positions while ignoring the physical structure. To improve the accuracy of the kinematic model, we present a kinematic modeling method with the addition of key points and coordinate systems to some components that failed to model the physical structure based on the classical method. Moreover, self-collision detection is also a primary problem for successfully completing the specified task of the mobile manipulator. In traditional self-collision detection technology, the description of each approximation is determined by the spatial transformation of each corresponding component in the mobile manipulator robot. Unlike the traditional technology, each approximation in the paper is directly established by the physical structure used in the kinematic modeling method, which significantly reduces the complicated analysis and shortens the required time. The numerical simulations prove that the kinematic model with the addition of key point technology is similar to the actual structure of mobile manipulator robots, and the self-collision detection technology proposed in the article effectively improves the performance of self-collision detection. Additionally, the experimental results prove that the kinematic modeling method and self-collision detection technology outlined in this paper can optimize the inverse kinematics solution.

2013 ◽  
Vol 461 ◽  
pp. 278-283 ◽  
Author(s):  
Jiang Hai Zhao ◽  
Xiao Dong Ye ◽  
Wen Huan Qian

Due to the space constraints and obstacles, the traditional industrial manipulator is too difficult to achieve some tasks, such as the gluing for the wing bulkhead of the aircraft and the maintenance for cooling pipes of the nuclear power plant, etc. Continuum manipulator, inspired by the trunk and the tentacle, proves to be very effective for above-mentioned tasks. A novel octopus-like biomimetic robots, is proposed in this paper, which is consisting of continuum joints and discrete joints, and provide a host of benefits, such as the large space of movement, the high flexibility and the heavy load. A novel analytical approach for solving kinematics of the octopus-like arm manipulator with mixed joints is presented in this paper. Based on the bionic mechanism of the continuum manipulator constructed from mixed joints, the robot configuration is established. In this paper, we present a detailed formulation and explanation of a novel kinematic model for the continuum robots with mixed joints. The modeling method based on the Denavit–Hartenberg parameters(also called DH parameters) is used to depict the motion of robot. The robot is comprised of the continuum joint and the rotated joint, so the kinematic model of continuum joint is crucial for constructing that of the whole robot. The continuum joint is equivalent to a section of elastic body, whose D-H parametors can be obtain from the constant-curvature method. Then the forward kinematics of the whole robot can be builded in a D-H frame. Research results will create a new modeling method for the octopus-like continuum manipulators with mixed joints, which can give a new approach for the design on the biomimetic manipulators operating in the unstructured envirement.


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Lu-Han Ma ◽  
Yong-Bo Zhong ◽  
Gong-Dong Wang ◽  
Nan Li

The robot kinematic model is the basis of motion control, calibration, error analysis, etc. Considering these factors, the kinematic model needs to meet the requirements of completeness, model continuity, and minimality. DH model as the most widely used method to build robot kinematic model still has problems in completeness, model continuity, and calculation, especially for robots with complex mechanisms such as closed chain mechanism and branch mechanism. In this paper, an improved kinematic modeling method is proposed based on the cooperation of the DH model and the Hayati and Mirmirani model and considering the Lie group concept. The improved model is complete and continuous, and when combining with Lie group to calculate, it avoids numbers of trigonometric functions and antitrigonometric functions in the process so as to optimize the algorithm. With this method, the kinematic model of the closed chain cascade manipulator developed in our laboratory is established, and a working process of it is numerically calculated. The results of the numerical calculation are basically consistent with those of virtual prototype simulation, which means the established kinematic model is correct and the numerical calculation method can solve the problem correctly. The kinematic model and the results of the kinematic analysis provide a theoretical basis for the subsequent motion control, calibration, and error analysis of the robot.


2012 ◽  
Vol 430-432 ◽  
pp. 2032-2036 ◽  
Author(s):  
Bao Qiang Wu ◽  
Wei Sun ◽  
Ming Hua Ouyang

Complex terrain conditions greatly influences the movement of mobile robot,which should not be neglected.In this paper,a novel motion modeling idea is proposed, in which the robot chassis attitude angle changes caused by topographic changes was real-timely measured and be input into the robot kinematic modeling process to establish the overall kinematic model of robot. This modeling method reflect the various parts of the robot motion relations, and also display the complex topography of the robot trajectory of the end of the actuator.Finally,validated and analyzed the feasibility of the modeling method.


Author(s):  
Abdelkrim Brahmi ◽  
Maarouf Saad ◽  
Brahim Brahmi ◽  
Ibrahim El Bojairami ◽  
Guy Gauthier ◽  
...  

In the research put forth, a robust adaptive control method for a nonholonomic mobile manipulator robot, with unknown inertia parameters and disturbances, was proposed. First, the description of the robot’s dynamics model was developed. Thereafter, a novel adaptive sliding mode control was designed, to which all parameters describing involved uncertainties and disturbances were estimated by the adaptive update technique. The proposed control ensures a relatively good system tracking, with all errors converging to zero. Unlike conventional sliding mode controls, the suggested is able to achieve superb performance, without resulting in any chattering problems, along with an extremely fast system trajectories convergence time to equilibrium. The aforementioned characteristics were attainable upon using an innovative reaching law based on potential functions. Furthermore, the Lyapunov approach was used to design the control law and to conduct a global stability analysis. Finally, experimental results and comparative study collected via a 05-DoF mobile manipulator robot, to track a given trajectory, showing the superior efficiency of the proposed control law.


2014 ◽  
Vol 4 (4) ◽  
pp. 267-285 ◽  
Author(s):  
Wenbing Zhao ◽  
Roanna Lun ◽  
Deborah D. Espy ◽  
M. Ann Reinthal

Abstract This article describes a novel approach to realtime motion assessment for rehabilitation exercises based on the integration of comprehensive kinematic modeling with fuzzy inference. To facilitate the assessment of all important aspects of a rehabilitation exercise, a kinematic model is developed to capture the essential requirements for static poses, dynamic movements, as well as the invariance that must be observed during an exercise. The kinematic model is expressed in terms of a set of kinematic rules. During the actual execution of a rehabilitation exercise, the similarity between the measured motion data and the model is computed in terms of their distances, which are then used as inputs to a fuzzy interference system to derive the overall quality of the execution. The integrated approach provides both a detailed categorical assessment of the overall execution of the exercise and the degree of adherence to individual kinematic rules.


Author(s):  
Michael John Chua ◽  
Yen-Chen Liu

Abstract This paper presents cooperation and null-space control for networked mobile manipulators with high degrees of freedom (DOFs). First, kinematic model and Euler-Lagrange dynamic model of the mobile manipulator, which has an articulated robot arm mounted on a mobile base with omni-directional wheels, have been presented. Then, the dynamic decoupling has been considered so that the task-space and the null-space can be controlled separately to accomplish different missions. The motion of the end-effector is controlled in the task-space, and the force control is implemented to make sure the cooperation of the mobile manipulators, as well as the transportation tasks. Also, the null-space control for the manipulator has been combined into the decoupling control. For the mobile base, it is controlled in the null-space to track the velocity of the end-effector, avoid other agents, avoid the obstacles, and move in a defined range based on the length of the manipulator without affecting the main task. Numerical simulations have been addressed to demonstrate the proposed methods.


2021 ◽  
Vol 15 (5) ◽  
pp. 599-610
Author(s):  
Md. Moktadir Alam ◽  
◽  
Soichi Ibaraki ◽  
Koki Fukuda

In advanced industrial applications, like machining, the absolute positioning accuracy of a six-axis robot is indispensable. To improve the absolute positioning accuracy of an industrial robot, numerical compensation based on positioning error prediction by the Denavit and Hartenberg (D-H) model has been investigated extensively. The main objective of this study is to review the kinematic modeling theory for a six-axis industrial robot. In the form of a tutorial, this paper defines a local coordinate system based on the position and orientation of the rotary axis average lines, as well as the derivation of the kinematic model based on the coordinate transformation theory. Although the present model is equivalent to the classical D-H model, this study shows that a different kinematic model can be derived using a different definition of the local coordinate systems. Subsequently, an algorithm is presented to identify the error sources included in the kinematic model based on a set of measured end-effector positions. The identification of the classical D-H parameters indicates a practical engineering application of the kinematic model for improving a robot’s positioning accuracy. Furthermore, this paper presents an extension of the present model, including the angular positioning deviation of each rotary axis. The angular positioning deviation of each rotary axis is formed as a function of the axis’ command angles and the direction of its rotation to model the effect of the rotary axis backlash. The identification of the angular positioning deviation of each rotary axis and its numerical compensation are presented, along with their experimental demonstration. This paper provides an essential theoretical basis for the error source diagnosis and error compensation of a six-axis robot.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Huangsheng Xie ◽  
Guodong Li ◽  
Yuexin Wang ◽  
Zhihe Fu ◽  
Fengyu Zhou

This paper focuses on the problem of visual servo grasping of household objects for nonholonomic mobile manipulator. Firstly, a new kind of artificial object mark based on QR (Quick Response) Code is designed, which can be affixed to the surface of household objects. Secondly, after summarizing the vision-based autonomous mobile manipulation system as a generalized manipulator, the generalized manipulator’s kinematic model is established, the analytical inverse kinematic solutions of the generalized manipulator are acquired, and a novel active vision based camera calibration method is proposed to determine the hand-eye relationship. Finally, a visual servo switching control law is designed to control the service robot to finish object grasping operation. Experimental results show that QR Code-based artificial object mark can overcome the difficulties brought by household objects’ variety and operation complexity, and the proposed visual servo scheme makes it possible for service robot to grasp and deliver objects efficiently.


2012 ◽  
pp. 274-294 ◽  
Author(s):  
Wen Bin Lim ◽  
Guilin Yang ◽  
Song Huat Yeo ◽  
Shabbir Kurbanhusen Mustafa

A Cable-Driven Robotic Arm (CDRA) possesses a number of advantages over the conventional articulated robotic arms, such as lightweight mechanical structure, high payload, fault tolerance, and most importantly, safe manipulation in the human environment. As such, a mobile manipulator that consists of a mobile base and a CDRA can be a promising assistive robot for the aging or disabled people to perform necessary tasks in their daily life. For such applications, a CDRA is a dexterous manipulator that consists of a number of cable-driven joint modules. In this chapter, a modular design concept is employed in order to simplify design, analysis, and control of CDRA to a manageable level. In particular, a 2-DOF cable-driven joint module is proposed as the basic building block of a CDRA. The critical design analysis issues pertaining to the kinematics analysis, tension analysis, and workspace-based design optimization of the 2-DOF cable-driven joint module are discussed. As a modular CDRA can be constructed into various configurations, a configuration-independent kinematic modeling approach based on the Product-of-Exponentials (POE) formula is proposed. The effectiveness of the proposed design analysis algorithms are demonstrated through simulation examples.


Author(s):  
Changya Yan ◽  
Feng Gao ◽  
Jie Chen

A virtual plant, built in a computer by using computer graphic (CG) and Virtual Reality (VR), can model the precise and whole structure of an integrated manufacturing system and simulate its physical and logical behavior in operation. This paper aims to reveal the advanced modeling and VR realization methods in developing a virtual forging plant for automatic and programmed open-die forging processes. Two sub-models, component model and process model, compose the overall modeling architecture of a virtual integrated open-die forging plant. The coordinated motion simulation of the integrated system is realized through a kinematic modeling method. A compound stiffness modeling method is then developed to simulate the mechanical behavior in operation. The process simulation of the virtual plant is conducted on the basis of the above two modeling methods. A practical application example of virtual plant for integrated open-die forging process is presented towards the end.


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