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In this paper, an adaptive impedance force control scheme for an n-link robot manipulator under unknown environment is proposed. The system dynamics of the robot manipulator is assumed that system model is not exactly known or has system uncertainty. Therefore, the traditional adaptive impedance force controller is not valid. Herein, the fuzzy neural networks are adopted to estimate the system model...
A finite-time adaptive force control scheme is designed for manipulators in the case of that the end-effectors are subjected to rheonomic constraints. There are three advantages of the proposed approach. (1) The finite-time convergence of force tracking error can be ensured. (2) The uncertainty of robotic parameters is solved by an adaptive control scheme. (3) Higher-precision motion tracking performance...
The paper presents a unilateral external leg-lengthening fixator driven by 2 DoFs (Degrees-of-Freedom) planar mechanism and a hybrid position/force control scheme. In this paper, we show that the leg lengthening by the process of “distraction osteogenesis” is able to be achieved by using the proposed robotic fixator. In the operation process, the bone is supposed to be cut into two segments, the proposed...
The small parts assembly process is a complex but necessary task in the modern manufacturing industry. It is not easy to use industrial robots to afford this task because different control modes and coordination algorithms have to be designed and updated periodically to adapt the rapidly changing products. It is desired to improve the conventional robot programming technology. The concept of Learning...
This paper proposes a two channel control architecture based on impedance transmission in time delayed teleoperation system. In conventional research, bilateral teleoperation is widely researched and bilateral control is used to obtain remote force imformation. However the performance is degraded and destabilized by time delay. Conventional approaches like smith predictor, communication disturbance...
This paper proposes an experimental validation of electro-hydraulic transmission for haptic teleoperation. Haptic teleoperation is an emerging technology that is designed to transmit position and force sensations of a distant environment to the human hand. Heretofore, it has been considered in several applications such as plant reparation, space exploration or laparoscopic surgery. So far, flexible...
Dynamic grasping force control for a multi-fingered robot hand is proposed and investigated in this paper. The grasping force of the finger is dynamically adjusted according to the three-axis tactile feedback so that each fingertip force always stays inside the friction cone detected by the fingertip three-axis tactile sensor without any undesired slip nor detaching from the object while grasping...
In practice, a lot of manufacturing tasks performed by robots involve extensive contact with objects in workplace. In such tasks it is required to control the forces of interaction between the manipulator and the objects directly. In order to apply these force control algorithms, force sensors must be used in a role of output feedback signals. However, in some applications force sensors are unsuitable...
It has been a challenge to design robots that possess intrinsic compliance, especially for robots that are required to achieve multi-DOF manipulation. Inspired by human limbs, robotic manipulators with internal compliance can perform high-quality force/torque control and better human-robot interaction. This paper presents a robotic wrist whose size, range, and torque output are comparable to those...
Vitreoretinal microsurgery requires precise hand-eye coordination to manipulate delicate structures within the eye on the order of tens of microns. To achieve these tasks, surgeons use tools of diameter 0.9 mm or less to access the eye's interior structures. The level of force required during these manipulations is often below the human tactile threshold, requiring the surgeon to rely on subtle visual...
The flying hand is a robotic hand consisting of a swarm of UAVs able to grasp an object where each UAV contributes to the grasping task with a single contact point at the tooltip. The swarm of robots is teleoperated by a human hand whose fingertip motions are tracked, e.g., using an RGB-D camera. We solve the kinematic dissimilarity of this unique master-slave system using a multi-layered approach...
This research aims to create a framework of transporting an object by multiple humanoid robots. In this work, a symmetric hybrid position/force control is adapted to two humanoid robots. The reference object position and attitude are given by an operator online, and the two humanoid robots generate its whole body motion to follow the reference object position properly. The result of proposed method...
A kind of electric gripper control system is introduced in this paper. The control system is based on three closed loops structure without a pressure sensor. The DSP and brushless DC motor are used as its control core and power component. The traditional PID control algorithm is used to design the current controller, speed controller and position/force controller. A current comparison method is considered...
In a cable-driven parallel robot, elastic cables are used to manipulate the end effector in the workspace. In this paper we present a dynamic analysis and system identification for the complete actuator unit of a cable robot including servo controller, winch, cable, cable force sensor and field bus communication. We establish a second-order system with dead time as an analagous model. Based on this...
In this paper, we propose a coordinated motion control algorithm of dual manipulators for handling of an almost rigid object but with non-negligible deformation. By the proposed algorithm, an almost rigid object with non-negligible deformation, such as a cardboard box, a plastic case, etc., is held and manipulated by dual manipulators stably without producing any vibrations. By defining apparent dynamics...
In this paper, experimental studies of bilateral teleoperation control of a quadrotor system are presented. Not only position control but force control of a quadrotor system is regulated by forming a force controlled loop. The contact force is measured by a load cell mounted on the top of the quadrotor system. The sensed force is used for a haptic device as an operator feels the force. This configuration...
This paper proposes a new adaptive design method for the robust force control systems based on disturbance observer (DOB). A DOB is a robust control tool that is widely used in motion control applications. It can also be used to estimate environmental impedance by identifying system uncertainties and is called as reaction torque/force observer (RTOB/RFOB). A RTOB/RFOB has several superiorities over...
This paper proposes a high performance electro-hydraulic force transmission method for force control of elbow-joint rehabilitation exoskeleton robot. Exoskeletons are external structural mechanisms that are designed to be mounted on human body so as to support or enhance its physical abilities. Heretofore, they have been considered in several applications such as rehabilitation medicine, military...
A sample acquisition and caching architecture has been developed for the proposed Mars 2020 mission that acquires samples directly into sample tubes in coring bits. Sample tubes are inserted and removed from the bits, seals are inserted into the tubes, and the tubes are placed in the sample canister. This paper describes initial algorithms, implementation, and test results where sample tube transfer...
Recently, technology which deals with tactile sense has attracted attention in various fields. In particular, researches about storing and reproducing human motion are one of important fields for the haptic technology. A motion-copying system is known as one of efficient methods to achieve storing and reproducing human motion. However, it is known that environmental condition change is serious problem...
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