Robot Kinematics Based on GAALOPWeb for MATLAB®

2021 ◽  
pp. 71-82
Author(s):  
Dietmar Hildenbrand
Keyword(s):  
Author(s):  
Martin Wagner ◽  
Andreas Bihlmaier ◽  
Hannes Götz Kenngott ◽  
Patrick Mietkowski ◽  
Paul Maria Scheikl ◽  
...  

Abstract Background We demonstrate the first self-learning, context-sensitive, autonomous camera-guiding robot applicable to minimally invasive surgery. The majority of surgical robots nowadays are telemanipulators without autonomous capabilities. Autonomous systems have been developed for laparoscopic camera guidance, however following simple rules and not adapting their behavior to specific tasks, procedures, or surgeons. Methods The herein presented methodology allows different robot kinematics to perceive their environment, interpret it according to a knowledge base and perform context-aware actions. For training, twenty operations were conducted with human camera guidance by a single surgeon. Subsequently, we experimentally evaluated the cognitive robotic camera control. A VIKY EP system and a KUKA LWR 4 robot were trained on data from manual camera guidance after completion of the surgeon’s learning curve. Second, only data from VIKY EP were used to train the LWR and finally data from training with the LWR were used to re-train the LWR. Results The duration of each operation decreased with the robot’s increasing experience from 1704 s ± 244 s to 1406 s ± 112 s, and 1197 s. Camera guidance quality (good/neutral/poor) improved from 38.6/53.4/7.9 to 49.4/46.3/4.1% and 56.2/41.0/2.8%. Conclusions The cognitive camera robot improved its performance with experience, laying the foundation for a new generation of cognitive surgical robots that adapt to a surgeon’s needs.


2021 ◽  
Vol 54 (1-2) ◽  
pp. 102-115
Author(s):  
Wenhui Si ◽  
Lingyan Zhao ◽  
Jianping Wei ◽  
Zhiguang Guan

Extensive research efforts have been made to address the motion control of rigid-link electrically-driven (RLED) robots in literature. However, most existing results were designed in joint space and need to be converted to task space as more and more control tasks are defined in their operational space. In this work, the direct task-space regulation of RLED robots with uncertain kinematics is studied by using neural networks (NN) technique. Radial basis function (RBF) neural networks are used to estimate complicated and calibration heavy robot kinematics and dynamics. The NN weights are updated on-line through two adaptation laws without the necessity of off-line training. Compared with most existing NN-based robot control results, the novelty of the proposed method lies in that asymptotic stability of the overall system can be achieved instead of just uniformly ultimately bounded (UUB) stability. Moreover, the proposed control method can tolerate not only the actuator dynamics uncertainty but also the uncertainty in robot kinematics by adopting an adaptive Jacobian matrix. The asymptotic stability of the overall system is proven rigorously through Lyapunov analysis. Numerical studies have been carried out to verify efficiency of the proposed method.


2020 ◽  
Vol 1624 ◽  
pp. 042029
Author(s):  
Dongkang He ◽  
Fangping Liu ◽  
Fuchun Wang

2018 ◽  
Vol 4 (1) ◽  
pp. 199-202
Author(s):  
Sebastian Becker ◽  
Wiebke Hinterlang ◽  
Tim Eschert ◽  
Catherine Disselhorst-Klug

AbstractStroke is one of the most frequent diseases among the elderly and often leads to an ongoing failure of functions in the central nervous system. Due to the plasticity of the brain affected may regain lost motor function by repetitive training. Robotic devices can be an approach to accelerate the rehabilitation process by maximizing patients’ training intensity. End-effector based robotic systems are particularly suitable for this purpose and often an advantage over exoskeletons since the proximal part of the upper limb remains under the control of the patient. Furthermore, the integration of the assistas- needed principle (AAN) into these devices enables individualized, adaptable robotic support to patients during therapy. In this study an end-effector based robotic rehabilitation device based on the Robot Operating System (ROS) framework is introduced. The system allows patients to perform 3- dimensional movements without a therapist’s assistance. With regard to the AAN, focus was based on impedance control and an additional real-time adaption of the impedance control parameters by using a feedback loop. 10 healthy subjects took part in this study to evaluate the overall concept with regard to usability and quality of the supported movement. Hence, the three most promising adaption models of AAN (without adaption, adaption according to position and time, adaption according to velocity) under three different levels of movement support (0%, 50%, 100%) were investigated by administering a self-designed questionnaire and the robot kinematics. The results showed no significant differences between the three different adaption models of AAN. However, the subjective assessment of the movements was in keeping with robot kinematics and the control approaches as well as the overall system have experienced remarkable support.


2011 ◽  
Vol 201-203 ◽  
pp. 1867-1872 ◽  
Author(s):  
Jian Ye Zhang ◽  
Chen Zhao ◽  
Da Wei Zhang

The pose accuracy of robot manipulators has long become a major issue to be considered in its advanced application. An efficient methodology to generate the end-effector position and orientation error model of robotic manipulator has been proposed based on the differential transformation matrix theory. According to this methodology, a linear error model that described the end-effector position and orientation errors due to robot kinematics parameters errors has been presented. A computer program to generate the error model and perform the accuracy analysis on any serial link manipulator has been developed in MATLAB. This methodology and software are applied to the accuracy analysis of a Phantom Desktop manipulator. The positioning error of the manipulator in its workspace cross section (XOZ) has been plotted as 3D surface graph and discussed.


Author(s):  
Mohammad Reza Elhami ◽  
Iman Dashti

In analyzing robot manipulator kinematics, we need to describe relative movement of adjacent linkages or joints in order to obtain the pose of end effector (both position and orientation) in reference coordinate frame. Denavit-Hartenberg established a method based on a 4×4 homogenous matrix so called “A” matrix. This method used by most of the authors for kinematics and dynamic analysis of the robot manipulators. Although it has many advantages, however, finding the elements of this matrix and link/joint’s parameters is sometimes complicated and confusing. By considering these difficulties, the authors proposed a new approach called ‘convenient approach’ that is developed based on “Relative Transformations Principle”. It provides a very simple and convenient way for the solution of robot kinematics compared to the conventional D-H representation. In order to clarify this point, the kinematics of the world known Stanford manipulator has been solved through D-H representation as well as convenient approach and the results are compared.


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