scholarly journals A Mechatronic Perspective on Robotic Arms and End-Effectors

10.5772/16234 ◽  
2011 ◽  
Author(s):  
Pinhas Ben-Tzvi ◽  
Paul Moubarak
Keyword(s):  
10.5772/5783 ◽  
2005 ◽  
Vol 2 (3) ◽  
pp. 26 ◽  
Author(s):  
Hanafiah Yussof ◽  
Mitsuhiro Yamano ◽  
Yasuo Nasu ◽  
Kazuhisa Mitobe ◽  
Masahiro Ohka

This paper describes the development of an autonomous obstacle-avoidance method that operates in conjunction with groping locomotion on the humanoid robot Bonten-Maru II. Present studies on groping locomotion consist of basic research in which humanoid robot recognizes its surroundings by touching and groping with its arm on the flat surface of a wall. The robot responds to the surroundings by performing corrections to its orientation and locomotion direction. During groping locomotion, however, the existence of obstacles within the correction area creates the possibility of collisions. The objective of this paper is to develop an autonomous method to avoid obstacles in the correction area by applying suitable algorithms to the humanoid robot's control system. In order to recognize its surroundings, six-axis force sensors were attached to both robotic arms as end effectors for force control. The proposed algorithm refers to the rotation angle of the humanoid robot's leg joints due to trajectory generation. The algorithm relates to the groping locomotion via the measured groping angle and motions of arms. Using Bonten-Maru II, groping experiments were conducted on a wall's surface to obtain wall orientation data. By employing these data, the humanoid robot performed the proposed method autonomously to avoid an obstacle present in the correction area. Results indicate that the humanoid robot can recognize the existence of an obstacle and avoid it by generating suitable trajectories in its legs.


Author(s):  
Reza Movassagh-Khaniki ◽  
Neda Hassanzadeh ◽  
Abhijit Makhal ◽  
Alba Perez-Gracia

Some robotic tasks, especially those in which there are interactions between manipulated objects, require the collaborative work of two robotic arms equipped with end-effector grippers or robotic hands. Most of the current applications in which a bimanual task is attempted by a robot use two robot arm manipulators with simple grippers, in which the end-effectors are used for grasping and the remaining motion is performed by the robotic arms. In this work, we propose the design of a highly dexterous multi-fingered robotic hand, able to perform the bimanual task when attached to a simple arm manipulator. Dexterous robotic hands can be designed with more than one splitting stage; their design for a task can be done using kinematic synthesis for tree topologies. The synthesis process is applied in this case to the design of a robotic hand with three palms for a bimanual task consisting of assembling an emergency stop button.


Robotica ◽  
2021 ◽  
pp. 1-31
Author(s):  
Ali Deylami ◽  
Alireza Izadbakhsh

Abstract This article addresses the problem of pose and force control in a cooperative system comprised of multiple n-degree-of-freedom (n-DOF) electrically driven robotic arms that move a payload. The proposed controller should be capable of maintaining the position and orientation of the payload in the desired path. In addition, the force exerted by robot end effectors on the object must remain limited. The system has unmodeled dynamics, and measuring the robot joint velocities is impossible. Therefore, a FAT-based observer–controller is designed to estimate the uncertainty and velocities based on universal approximation property of Fourier series expansion. The stability of the system is confirmed based on Lyapunov’s stability theorem. Finally, the proposed adaptive controller–observer is applied on two 3-DOF cooperative robotic arms carrying a payload, and the results are precisely analyzed. The results of the proposed approach are also compared with two state-of-art powerful approximation method.


Author(s):  
Silvia Frumento ◽  
Rinaldo C. Michelini ◽  
Rainer Konietschke ◽  
Ulrich Hagn ◽  
Tobias Ortmaier ◽  
...  

The development of a remotely operated, Co-Robotic Positioning Device (CRPD) for instrumental backing and optimal base position to robotic arms in tele-surgery is discussed. To optimise the setting of robotic operating rooms (ROR) by reducing the structures’ size around the patient and by selecting task-driven layouts, the design of a hanging servo-carrier coming from the ceiling is chosen, rather than a device located on the floor. The present study prospects a split-duty approach, distinguishing the Co-Robotic Positioning Device, CRPD, from the front-end effectors, each subsystem hierarchically controlled by remote location, in keeping with optimal protocols. The attention is focused on the slave-carrier, to establish an optimal design of the CRPD, based on the characteristics of robotic effectors and the surgical task. The CRPD is conceived to support (up to four) robotic effectors, each one equipped with proper tools (endoscope, scalpels, scissors, suture needles, etc.). The CRPD, actually, by optimally positioning the robotic arms, avoids the need of manual deployment, in current setups often necessary to avoid singularities or collisions. The Automatic Changing Device for Surgical Tools, ACD-ST, is another significant device of the conceived slave-carrier. It allows the tele-operating surgeon to change the tools (scalpels, scissors, etc.) by a direct command from his console. Example applications aim at ticklish endoscopic/tomic operations that require high accuracy with low involved forces such as cardio-thoracic-surgery, abdominal surgery, spine-surgery, microsurgery (neurosurgery, hand-surgery, ophthalmic-surgery, ear-nose-throat surgery), say, the typical domains of MIRS, where robotic surgery is quickly expanding.


2020 ◽  
Vol 4 (2) ◽  
pp. 48-55
Author(s):  
A. S. Jamaludin ◽  
M. N. M. Razali ◽  
N. Jasman ◽  
A. N. A. Ghafar ◽  
M. A. Hadi

The gripper is the most important part in an industrial robot. It is related with the environment around the robot. Today, the industrial robot grippers have to be tuned and custom made for each application by engineers, by searching to get the desired repeatability and behaviour. Vacuum suction is one of the grippers in Watch Case Press Production (WCPP) and a mechanism to improve the efficiency of the manufacturing procedure. Pick and place are the important process for the annealing process. Thus, by implementing vacuum suction gripper, the process of pick and place can be improved. The purpose of vacuum gripper other than design vacuum suction mechanism is to compare the effectiveness of vacuum suction gripper with the conventional pick and place gripper. Vacuum suction gripper is a mechanism to transport part and which later sequencing, eliminating and reducing the activities required to complete the process. Throughout this study, the process pick and place became more effective, the impact on the production of annealing process is faster. The vacuum suction gripper can pick all part at the production which will lower the loss of the productivity. In conclusion, vacuum suction gripper reduces the cycle time about 20%. Vacuum suction gripper can help lower the cycle time of a machine and allow more frequent process in order to increase the production flexibility.


Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3498
Author(s):  
Youqiang Zhang ◽  
Cheol-Su Jeong ◽  
Minhyo Kim ◽  
Sangrok Jin

This paper shows the design and modeling of an end effector with a bidirectional telescopic mechanism to allow a surgical assistant robot to hold and handle surgical instruments. It also presents a force-free control algorithm for the direct teaching of end effectors. The bidirectional telescopic mechanism can actively transmit force both upwards and downwards by staggering the wires on both sides. In order to estimate and control torque via motor current without a force/torque sensor, the gravity model and friction model of the device are derived through repeated experiments. The LuGre model is applied to the friction model, and the static and dynamic parameters are obtained using a curve fitting function and a genetic algorithm. Direct teaching control is designed using a force-free control algorithm that compensates for the estimated torque from the motor current for gravity and friction, and then converts it into a position control input. Direct teaching operation sensitivity is verified through hand-guiding experiments.


Author(s):  
Unai Zabala ◽  
Igor Rodriguez ◽  
José María Martínez-Otzeta ◽  
Elena Lazkano

AbstractNatural gestures are a desirable feature for a humanoid robot, as they are presumed to elicit a more comfortable interaction in people. With this aim in mind, we present in this paper a system to develop a natural talking gesture generation behavior. A Generative Adversarial Network (GAN) produces novel beat gestures from the data captured from recordings of human talking. The data is obtained without the need for any kind of wearable, as a motion capture system properly estimates the position of the limbs/joints involved in human expressive talking behavior. After testing in a Pepper robot, it is shown that the system is able to generate natural gestures during large talking periods without becoming repetitive. This approach is computationally more demanding than previous work, therefore a comparison is made in order to evaluate the improvements. This comparison is made by calculating some common measures about the end effectors’ trajectories (jerk and path lengths) and complemented by the Fréchet Gesture Distance (FGD) that aims to measure the fidelity of the generated gestures with respect to the provided ones. Results show that the described system is able to learn natural gestures just by observation and improves the one developed with a simpler motion capture system. The quantitative results are sustained by questionnaire based human evaluation.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 410
Author(s):  
Dan Liu ◽  
Xiaoming Liu ◽  
Pengyun Li ◽  
Xiaoqing Tang ◽  
Masaru Kojima ◽  
...  

In recent years, micromanipulators have provided the ability to interact with micro-objects in industrial and biomedical fields. However, traditional manipulators still encounter challenges in gaining the force feedback at the micro-scale. In this paper, we present a micronewton force-controlled two-finger microhand with a soft magnetic end-effector for stable grasping. In this system, a homemade electromagnet was used as the driving device to execute micro-objects manipulation. There were two soft end-effectors with diameters of 300 μm. One was a fixed end-effector that was only made of hydrogel, and the other one was a magnetic end-effector that contained a uniform mixture of polydimethylsiloxane (PDMS) and paramagnetic particles. The magnetic force on the soft magnetic end-effector was calibrated using an atomic force microscopy (AFM) probe. The performance tests demonstrated that the magnetically driven soft microhand had a grasping range of 0–260 μm, which allowed a clamping force with a resolution of 0.48 μN. The stable grasping capability of the magnetically driven soft microhand was validated by grasping different sized microbeads, transport under different velocities, and assembly of microbeads. The proposed system enables force-controlled manipulation, and we believe it has great potential in biological and industrial micromanipulation.


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