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A multi-fingered universal robot hand has been developed in order to construct the platform of humanoid hand study. We also have developed a small and five-fingered robot hand. The robot hand is designed to protect the small driving system from a large external force. This protection mechanism is small enough to be installed in the joint driving me...
Citations
... In [52], a roller based torque limiter is described for robotic application. The transmitted torque depends on the roller angle, geometry, friction coefficient and normal force applied to the rollers. ...
Safety and reliability of electrical actuators are essential for success of all electric and more electric aircrafts (MEA). Torque limiters improve the reliability of electromechanical actuators (EMA) by restricting the amount of force experienced by the actuator drive train components. If transmitted torque in the shaft exceeds a limit, it gives way in a controlled manner. This protects the actuator from potential failure and jamming. In this paper, different types of existing torque limiters are investigated for their suitability in aerospace EMA application and further integration within the electric motor. They classified based on the torque transmission mechanism and each type is described in detail. Operating principle and basic characteristics are reported. Comparative evaluation of commercially available devices is presented. It is found that those based on friction based and permanent magnet are most suitable due to their good torque density, reliability and high speed capability. Further, based on the characteristics, integration of torque limiter within the actuator motor is investigated in this paper. An example actuator motor is considered for integration. Different integration options suitable for the different types of torque limiting devices are described. Reduction in overall volume is shown for the integration options. Such integration can lead to improved reliability as well as higher power density resulting in next-generation actuator electrical drives for MEA.
... Thus, this allows stable grasping but at a cost of highly complicated position and torque control of each joint. Ueda et al. (2010) and Fukui et al. (2009) have designed a full non-tendon-driven robot hand with four fingers (12 DOF) and five fingers (20 DOF), respectively. They both have allocated a dedicated PC for the computation of the control algorithms for the grippers. ...
Grippers developed in recent years either cannot achieve a complete universality due to grasping stability issues or are designed with excessive complexity. In this paper, the design of a three-fingered tendon-driven integrated gripper based on the concept of integrating Universal Active Gripper (UAG) with Universal Passive Gripper (UPG) fingertips, which ensures achieving adjustable fingertip stiffness and is practically proven to solve grasping stability issues, is proposed. Furthermore, kinematic, dynamic, and force analyses was conducted to calculate the specifications of the designed gripper, which was compared to four commercial grippers. Finite element analysis was also carried out for the designed gripper. When the final design of the gripper was compared to that of Hou et al.'s (2018) (the only comparable design present for the integrated gripper), one crucial similarity noted was based on both designs adopting the same kinematic configuration. This fact further increases the confidence in the optimal development of the designed gripper. According to FEA results, the maximum stress acting on the components of the gripper was 15.78 MPa, 39.45% of the yield stress of Acrylonitrile Butadiene Styrene (ABS). In conclusion, it was theoretically established that the designed gripper with the tendon-driven actuation is operating efficiently.
... Three main methods have been proposed for grippers to achieve more flexible and universal grasping, i.e., adding more fingers or joints to rigid gripper, making the stiffness of the fingers be changeable, and using soft material fingers driven by pneumatic actuators. Multi-fingered gripper takes advantage of multiple joints to ensure universality [1][2][3][4][5][6][7][8][9][10] . However, some typical prototypes, such as Anthropomorphic Robotic Hand with 12 joints [1] , Universal robot hand Ⅱ with 16 joints [2] , and Twist Drive with 18 joints [6] , are extremely complicated. ...
... Multi-fingered gripper takes advantage of multiple joints to ensure universality [1][2][3][4][5][6][7][8][9][10] . However, some typical prototypes, such as Anthropomorphic Robotic Hand with 12 joints [1] , Universal robot hand Ⅱ with 16 joints [2] , and Twist Drive with 18 joints [6] , are extremely complicated. For stiffness adjustable gripper, Positive Pressure Jamming Gripper and MR gripper [11][12][13][14] utilize jamming effect and magnetorheological effect to vary finger stiffness to achieve a more flexible grasping. ...
... Different from the multi-fingered grippers [1][2][3][4][5][6][7][8][9][10] , stiffness changeable grippers [11][12][13][14] , and soft gripper with pneumatic actuators [15,16] , we firstly proposed the idea of a universal parallel-fingered hand with soft fingertips based on jamming effect, in which negative pressure and particle flow were utilized to achieve variable stiffness as shown in Video 1. The jamming effect is adopted in the system for the simplicity to control and configuration with considerable stiffness span [25][26][27][28] . ...
The goal of robotic manipulators is to grasp objects of irregular shapes with better pre- cision and efficiency. Universal grippers developed in recent years are designed with ex- cessive complexity or lower resistance to damage. In this paper, we propose the idea of a universal parallel-fingered hand with soft fingertips based on jamming effect, in which negative pressure and particle flow are utilized to achieve variable stiffness. Then we set up a whole pick-and-place experiment system to evaluate the operational performance in the real serving situations. The results indicate that for most rigid objects, our prototype with soft fingertips, the stiffness of which is over the threshold to bear maximum task load after jamming, can demonstrate higher grasping stability than rigid ones, reduce around 40% motor drive power consumption and have a higher load capacity compared with the rigid-fingertip prototype under stable grasping, and have a relatively better operating pre- cision of ±0.62 mm compared to most of previous soft grippers when placing objects with equal weight. The findings can facilitate to improve the grasping precision of mechanical hands with soft fingertips.
... Most of these research groups have established an active compliance control via a specific sensor. They have developed their own robotic hands such as a DLR [6] and a Universal [7] robotic hand. Their aim is mainly to create a biomechanically realistic human hand. ...
... Similarly, weight of the finger is also reduced to make the overall hand feel lighter. The finger of universal hand (2012) [38] only weighs about 0.250kg. This is a slightly less than DLR hand II (2001) [13] finger which weighs around 0.375kg. ...
This paper presents the novel mechanical design of an ambidextrous finger specifically designed for an ambidextrous anthropomorphic robotic hand actuated by pneumatic artificial muscles. The ambidextrous nature of design allows fingers to perform both left and right hand movements. The aim of our design is to reduce the number of actuators, increase the range of movements with best possible range ideally greater than a common human finger. Four prototypes are discussed in this paper; first prototype is focused on the choice of material and to consider the possible ways to reduce friction. Second prototype is designed to investigate the tendons routing configurations. Aim of third and fourth prototype is to improve the overall performance and to maximize the grasping force. Finally, a unified design (Final design) is presented in great detail. Comparison of all prototypes is done from different angles to evaluate the best design. The kinematic features of intermediate mode have been analysed to optimize both the flexibility and the robustness of the system, as well as to minimize the number of pneumatic muscles. The final design of an ambidextrous finger has developed, tested and 3D printed.
... Although there have been works presenting the use of torque limiting devices for robot safety [10], [11], [12], [13], our work is to our knowledge the first to analyse the instability phase after overload events, and to propose a possible solution for dealing with it. ...
Robotic technology has made significant progresses in the past years. Robots are now common in large manufacturing plants and other industrial settings, safely confined in closed work cells. But to be even more helpful, robots need the capability of interacting physically with humans, and with unstructured environments. This poses new challenges in the design of safe robotic systems. In this article we addressed this problem by proposing a novel design for the joints of the iCub robot. The new design provides the robot with an overload protection mechanism. The overload protection acts as a "passive" torque saturator, which is intrinsically safe. We constructed a prototype of a robotic joint that implements this approach. We first show that our solution is effective in a typical impact scenario. We then evaluate the possible problems arising when the device is controlled with a position control loop. We show that a conventional feedback control loop can trigger positive feedback and instability. Operating the actuator in these conditions is dangerous and can lead to severe failures. We therefore propose the implementation of a relatively simple control strategy that allows to avoid this situation by monitoring slippage, without additional sensors. The quantitative evaluations in the paper demonstrate that our approach is effective and can improve the robustness and safety of complex robotic systems. Indeed these aspects are particularly critical in the case of humaniod robots that are systems prone to severe whole-body impacts in unstructured environments (e.g. falling).
... We cite this paper to show how multi-problematic the task is to create Robotic Nurse technology. Each next step in human hand approximation requires introduction of additional sensors, functions and algorithms of operation [18]. In the cited paper, a robot hand system is described that has tactile sensors, joint torque sensors, joint angle sensors and a similar structure to human hands. ...
This paper presents the concept, structural design and implementation of components of a multifunctional sensory network, consisting of a Mobile Robotic Platform (MRP) and stationary multifunctional sensors, which are wirelessly communicating with the MRP. Each section provides the review of the principles of operation and the network components' practical implementation. The analysis is focused on the structure of the robotic platform, sensory network and electronics and on the methods of the environment monitoring and data processing algorithms that provide maximal reliability, flexibility and stable operability of the system. The main aim of this project is the development of the Robotic Nurse (RN)-a 24/7 robotic helper for the hospital nurse personnel. To support long-lasting autonomic operation of the platform, all mechanical, electronic and photonic components were designed to provide minimal weight, size and power consumption, while still providing high operational efficiency, accuracy of measurements and adequateness of the sensor response. The stationary sensors serve as the remote "eyes, ears and noses" of the main MRP. After data acquisition, processing and analysing, the robot activates the mobile platform or specific sensors and cameras. The cross-use of data received from sensors of different types provides high reliability of the system. The key RN capabilities are simultaneous monitoring of physical conditions of a large number of patients and alarming in case of an emergency. The robotic platform Nav-2 exploits innovative principles of any-direction motion with omni-wheels, navigation and environment analysis. It includes an innovative mini-laser, the absorption spectrum analyser and a portable, extremely high signal-to-noise ratio spectrometer with two-dimensional detector array.
... Many other robot hands have been developed and researched [8,9]. We have also reported the universal robot hands I [10] and II [11]. ...
A haptic feedback system is required to assist telerehabilitation with robot hand. The system should provide the reaction force measured in the robot hand to an operator. In this paper, we have developed a force feedback device that presents a reaction force to the distal segment of the operator's thumb, middle finger, and basipodite of the middle finger when the robot hand grasps an object. The device uses a shape memory alloy as an actuator, which affords a very compact, lightweight, and accurate device.
... A variety of other robot hands have been developed [8], [9]. We also have developed the universal robot hand I [10] and II [11]. These robot hands have been developed in order to work various tasks. ...
The multi-fingered robot hand has much attention in various fields. Many robot hands have been proposed so far. We have also developed a small and five-fingered robot hand in order to carry out various tasks. However, the robot hand cannot execute any tasks autonomously because the robot hand does not have enough motion and sensing ability to task complexities. Therefore, we have developed a robot hand tele-operation system in order to work complex tasks with human help and proposed the control method with tele-presence. In this paper, we propose a robot hand tele-operation system in consideration of the human and the robot hand structure. Here, these is a difference in the structures of the human and the robot hand, so the robot hand is tele-operated according to the fingertip trajectory of the human hand.
The large interest in robot hands and active hand prostheses has in recent years been joined by that in active hand orthoses. Despite the differences in intended uses, these three categories of artificial hand devices share key characteristics. Examination of the commonalities could stimulate future design. Thus, we undertook a comparative review of publications describing robot hands, active prostheses, and active orthoses, with a focus on mechanical structure, actuation principle, and transmission. Out of a total of 510 papers identified through the literature search, 72 publications were included in a focused examination. We identified trends in the design of artificial hands and gaps in the literature. After comparing their mechanical aspects, we propose recommendations for future development.
