Force Transmission Control in Multilateral System for Teletraining

Recently, skill preservation of an expert has been a serious problem of the medical or production fields. This paper proposes a skill preservation system for motion acquisition of human fingers. The proposed skill preservation system is composed of a master-slave system, and the control system is based on bilateral motion control. Since a touching motion is subject to the law of action and reaction, it is possible to decompose force information into action force and reaction force by using the bilateral control. Furthermore, human motion is acquired in decoupled modal space by using the mode quarry matrix. The decoupled modes correspond to moving, yawing, tasks, and so on. Thus the skilled motion by a human is easily obtained in the modal space. The mode quarry matrix is also applied for temporal decomposition. As a result, modal and temporal analyses are realized by using the mode quarry matrices. The proposed skill preservation system is applied for grasping motion by three fingers. The experimental results show viability of the proposed method.

Force feedback controller (haptic device) is the key part of a master-slave tele-operation system. It can transmit its position, orientation and velocity to remotely operate the controlled object; at the same time it can acquire information of force/torque from the remote object, and rebuild those to the operator by enabling a force sense telepresence. In this paper, a new type force feedback controller with a 6 DOF Delta parallel mechanism is presented considering the performance of easy operation and precise force feedback. Firstly, the structure and control system of the force feedback controller are introduced, then its kinematics and statics models are analyzed as well as the force feedback control scheme. Moreover, a combined simulation model is established based on "Adams" and "Simulink" to valid the performance of the force feedback controller. Simulation results demonstrate that the established kinematic model and force feedback control scheme are precise and effective, which can provide beneficial guidance for design and application of the tele-operation system.

The manipulator with force feedback is a key interface device for a master-slave manipulation system with tele-presence technology. It can provide the operator with the real information of the operating environment. The structure, performance and principle of 6-DOF force feedback manipulator based on Stewart platform are introduced in this paper, and also the force feedback bilateral servo control algorithm. This improved algorithm synthesized displacement symmetry and force feedback control strategy. Slave manipulator adopts displacement servo control, and the force feedback adopts different gain displacement symmetry servo control algorithm. When there is no load on the slave manipulator, force feedback produced by the displacemental error in traditional symmetry type bilateral servo control method is cancelled. The operator can feel the stiffness when the slave grabs different objects. This algorithm is more effective than the traditional bilateral servo control method and combines with symmetry servo control, the slave's state can be reflected more really.

This paper evaluates the performance of a new control scheme for bilateral master-slave teleo- perator, introduced earlier, and compares it to pub- lished control methods by using a mathematical cri- terion based on the two-port network model. It is shown that most of the published control laws under investigation do not achieve optimal performance, and the few that do, require perfect estimation (or exact knowledge) of the human operator or master arm dynamics. It is also shown that optimal performance, based on the selected mathematical criterion, can be obtained using the proposed control law: I. INTRODUCTION Teleoperating systems may be viewed as synergistic systems composed of human operators and master-slave manipulators which interact with the physical world. The master, sometimes called hand controller, is used to gen- erate commands (usually position, rate or force commands) to its remotedly located counterpart called slave. In gen- eral, the position/velocity command from the operator is fed forward to the slave, while the reaction force, due to mechanical interaction with the environment, is fed back to the master, providing contact force information to the human operator. By reflecting the measured force back to the master arm, it is said that the teleoperator is controlled bilaterally. One of the main issues in telerobotics is control of master-slave teleoperators. A number of control metho- dologies have been proposed in the teleoperator literature. There are two main methods for controlling master-slave teleoperators. The first, a more traditional approach, uses position and/or velocity error (between the master and slave) to generate a forcehorque command into the master arm. The position/velocity of the master and slave are measured by sensors usually located at the joints. The second method uses direct force feedback, rather than posi- tion and velocity errors, to generate command signals to the master. This method uses a force/torque signal obtained from a sensor, usually located at the end-effector of the slave, to provide the operator with the force feeling of the remotedly located counterpart. The force feedback control is usually considered superior because of the more precise nature of the feedback signal. The two-port model network theory has been exten- sively used for the analysis of circuits in which bi- directional energy flows are present at two distinct pairs of terminals. This method provides a useful linear representa- tion of complex networks which exchange energy. The two-port model theory is also used in bilateral teleoperator systems (1,3-81, with force and velocity sensing at the mas- ter and slave. The interfaces between the human operator and master, and between the environment and slave are ports through which the teleoperator is designed to exchange energy between the operator and environment. Recently, several algorithms have been proposed to

The emergence of low cost hap tic devices and the evolution of technologies for developing virtual reality environments for web have motivated the development of tools that allow the use of hap tic systems together with applications and web browsers. The availability of web hap tic systems results on the possibility of multisensory experiences for internet users. This paper analyzes technologies for integrating hap tic and web systems, exposing the features of each tool in order to find the best strategy to incorporate virtual touch in Museu3l by using the hap tic technology, so that it becomes one of the first virtual museums that makes hap tic interaction with a work of art in a web visit possible.

Virtual reality (VR) applications for surgical planning and mentoring are currently becoming more widespread. Within these fields of applications, haptic systems are crucial to help the understanding of the feedback provided by the tissue during the interaction with the surgical tool. The accuracy of the VR scenario is related to many aspects, among them the ability of the haptic device to provide the force feedback and thus the adoption of proper characterization and modeling of the soft tissue behavior during deformation. This paper presents the current development concerning a VR environment to be equipped with a force feedback haptic device to simulate and experience clamping in colorectal surgery. The reaction at the clamp handle is provided starting from a FEA of the contact between the surgical tool and the tissue, coupled with the kinematic analysis of the mechanism. Connecting the virtual scenario to a microcontroller board, the reaction force is applied to the the haptic device, shaped as a clamping tool handle, so that the user may experience the tissue impedence during clamping. By simulations made through Simscape, a concept is evaluated according to some simulation paths that involve common scenarios of the virtual reality experience (such as collision, partial or total clamping operation). The novelty of the research regards the system design oriented to increase the accuracy of the soft tissue material behaviour through a preliminary off-line dedicated FEA investigation. Through Simulink simulations, the system design is verified so that the VR system set-up may be carried out. The results highlighted: (a) a good correspondence among the theoretical study of the reference kinematism that the haptic device must reproduce; (b) the implementation of a bilinear material model, derived off-line from FEA, is suitable to capture hyperelastic and geometric non-linearities of the soft tissue; (c) the feasibility of the open loop haptic control in accordance to the explored kinematism. The final goal of the research is to propose a system design approach able to tune the VR experince for teaching and mentoring through a in-house set-up easy to be tailored.

As haptic technology has advanced in the past decade, many sensor devices have been built and commercialized for providing the sense of action/reaction forces or moment feedback to the human operator. In the ideal bilateral control of the haptic system, the force and position control should achieve with the same actions of force and motion movements. An external force should be sensed quickly after contact with an unknown environment. This paper presents formulation and application of a Kalman filtering technique for control of master-slave robots contacting environment in a bilateral control. The different types of motion sensors are mounted on each robot to provide the position and acceleration data in the horizontal dimension. A Kalman-filter-based state observer and a Kalman-filter-based disturbance observer have been designed to estimate action/reaction forces. This paper also deals with the construction of bilateral control with the use of data provided by the different types of motion sensors. Compared to the other conventional disturbance observer or state observer, the bilateral control system based on the proposed method offers the advantages of wider bandwidth, faster response, and free from sensor noise. Thus, it is possible to provide high transparency and good perception of the environmental stiffness. The experimental results are provided to illustrate the performance of the proposed algorithms.

Recent advances in control technology have contributed to the development of robot systems for communication with humans. Robot systems recognize the environment on the basis of audio-visual information. Recognition methods based on audio-visual feedback have been developed by many researchers. Recently, haptic information has attracted attention as the third type of multimedia information. This paper proposes a force feedback method for systems with different motion areas, named “mobile-hapto”. Sense of touch is useful for remote manipulation. The mobile-hapto consists of a mobile robot with an infinite area for motion and a joystick that is fixed at a given position and can be operated manually. To realize of force feedback in the “mobile-hapto”, bilateral control with dimensional scaling is proposed. In this case, intuitive manipulation becomes possible when using the “mobile-hapto”. The effectiveness of the proposed method is verified by experimental results.

When we operate a robot hand remotely with tele-operation system, it is difficult to operate the robot hand collectly because of the reaction force without. Thus the haptic feedback system is required to provide reaction force resulting in the robot hand to an operator. In this paper, we develop the exoskeleton for force feedback to present reaction force in an operator based on force data measured from the robot hand system. By using a Shape Memory Arroy as an actuator the exoskelton is very compact, lightweight, the structure is simple and easy maintenance. Build a Force Feedback System using a data glove and the exoskeleton, the performance of this system is evaluated.

Haptics-enabled virtual reality technologies allow users to sense force feedback and tactile feedback while manipulating 3D objects. This paper proposes a haptic gaming system which can contribute to improve the ability for discerning tactile textures and 3D shapes by using force and tactile feedbacks of the users’ fingers. Our haptic gaming system consists of three games: “Haptic Puzzle” for tactile texture cognition, “Shape Puzzle” for 3D geometric object cognition, and “Position Puzzle” for 3D space cognition. Through a number of experiments, we have confirmed the effectiveness of our system on enhancing the tactile textures and 3D shapes recognition. The discrimination test of four haptic properties (stiffness, damping, static friction, and dynamic friction) led us to confirm that the users were least sensitive with damping property, and the damping changes were also highly confused with stiffness changes. We also found that the stiffness and damping properties are more influential than friction properties for discriminating the objects via the tactile texture recognition test. The final experiment demonstrated that the visuo-haptic integrated recognition was more advantageous than single haptic recognition. Moreover, this work showed the feasibility that the proposed system can be used for evaluating one’s haptic visual discrimination capability.

In this paper, we deal with a remote haptic instruction system in which a teacher teaches a student how to write characters by using haptic interface devices. We have two cases in the system. In one case, a pen is attached to only the student terminal, and video is transmitted from the student terminal to the teacher terminal. In the other case, a pen is attached to each of the two terminals, and video is transmitted bi-directionally between the terminals. In both cases, we make a comparison between two-way transmission and one-way transmission of the sense of force by subjective assessment.

Force display using a hybrid haptic device composed of motors and brakes

Delta robot is a parallel robot with rigid body and fast movement potential that suitable for human interface device via bilateral control. The workspace is relatively small due to the complex interference between three legs and lead to various size of delta robot to compatible with the preference work. As the size is vary, the kinematic and dynamic of delta robot is also difference and required new control method to compensate the changing kinematic such as micro/macro bilateral control in task space. However, those method required high calculation power to calculate the position and force feedback by using angular motor position and torque from disturbance observer. New approach of speed and force bilateral control to reduce the complexity and computational time by using Jacobian matrix (J) is proposed. The angular velocity of motor is calculated within disturbance observer. The simulation is carry out to verify the proposed method.

This paper introduces networked tank gunnery skill training based on haptic interaction. “Hand in hand” training mode is implemented by constructing a networked haptic display system. A teacher and a trainee can respectively manipulate his own haptic device to realize skill transferring. In this process, the trainee can experience the teacher's motor skill and can be corrected by the teacher. A local network is built to connect two haptic devices and computers. Two modes for tank gunnery skill training are designed in this system: haptic guidance and real-time correction. A prototype system is established to testify the effectiveness of such a new type “Hand in hand” training system.

Bilateral control system has been developed as a method to transmit tactile sense in order to be applied to handling radioactive material, operating unmanned underwater vehicles, space robotics, telesurgery, etc. Bilateral control system is able to transmit tactile sense to only one operator. To transmit tactile sense to multiple operators, multilateral control was expanded from bilateral control. However, tactile sense of environment which general multilateral control system transmits to an operator is significantly affected by other operators' motion. This paper proposes a novel control system which transmits environmental impedance to multiple operators. The proposed system uses master-slave system consisting of multiple master robots and a single slave robot. Both position and force information is transmitted bi-directionally between each master robot and a slave in the proposed system, whereas the information is transmitted among all robots in general multilateral control system. In addition, a method to estimate environmental impedance given by spring-damper model is proposed, since the proposed control system requires real-time estimation of environmental impedance. The validity of the proposed system is confirmed by simulation and experiment.