Bilateral Control System Research Articles

Investigation on Standardization of Modal Space by Ratio for MDOF Micro-Macro Bilateral Teleoperation Control System

This paper presents the research on micro-macro bilateral teleoperation control system of two ink planar manipulator. The micro-macro bilateral control system consists of different size between master and slave system using geared DC-motor. Both master and slave manipulators are actuated by DC-Micromotor attached to planetary gearhead to increase the output torque. In the previous researches the most common actuators used were linear motor and direct-drive DC motors. However, the application of DC motor with gearhead are vast in industry, which need high output force or torque. Thus in this paper, research on micro-macro bilateral teleoperation control system is proposed with the use of gear with the DC-motor. The micro-macro bilateral teleoperation control system provides the human operator with a sense of feel to a micro or macro environment as if it is in the same scale environment. Thus a standardization method is proposed to achieve micro-macro bilateral teleoperation control system. During the experiment, experiment on free motion and contact motion are conducted to validate the proposed setup in bilateral teleoperation control system. The position and torque responses of both master and slave manipulators are observed. The operationality and reproducibility of this proposed system are evaluated through proposed experimental results.

Investigation on MDOF Bilateral Teleoperation Control System Using Geared DC-Motor

This paper presents the research on bilateral teleoperation control system of two link planar manipulator. The bilateral control system consists of master and slave system using geared DC-motor. Both master and slave manipulators are actuated by DC-Micromotor attached to planetary gearhead to increase the output torque. In the previous researches, the common used actuators were linear motors and direct drive DC motor. However, the application of DC motor with gearhead is vast in industry, due to the need for high output force or torque. Thus in this paper, a deeper research on bilateral teleoperation control system is proposed with implementation of gear into the DC-motor. The modelling of multi-degrees-of-freedom (MDOF) bilateral teleoperation control system is designed with the implementation of workspace observer (WOB), reaction force observer (RFOB), position controller and force controller. During the experiments, free motion and contact motion were conducted to validate the proposed setup in bilateral teleoperation control system. The position and torque responses of both master and slave manipulators were observed. The operationality and reproducibility of this proposed system were evaluated through experimental results. Ultimately, this paper focused on the performance of the proposed setup and is analysed by using reproducibility and operationality.

機能的電気刺激を用いた人―機械のバイラテラル制御

Recently, human activity support systems by remote control of robots have been developed. Bilateral control is an effective control system of teleoperation because it can transmit the information of position and force. However, it is difficult to design multi-degree-of-freedom wearing robots that have used in previous studies. It can be solved by using functional electrical stimulation (FES) in the teleoperation system. On the other hand, there are only few studies of human-machine bilateral control systems using FES and they are not sufficient because the control systems have not been compared. This paper considers bilateral control systems using FES through comparative analysis.

Fast Estimation of Environment's Stiffness for Bilateral Control Systems with Communication Delay

Fast Estimation of Environment's Stiffness for Bilateral Control Systems with Communication Delay

Bilateral Control System of Flexible Master-Slave Arms with Random Delay Using Kalman Filter

Bilateral Control System of Flexible Master-Slave Arms with Random Delay Using Kalman Filter

A Bilateral Control System to Synchronize with Haptic and Visual Sense for Teleoperation over Network

A Bilateral Control System to Synchronize with Haptic and Visual Sense for Teleoperation over Network

Bilateral Control of a Velocity Control System Using Electric and Hydraulic Actuators

SUMMARYWorking in extreme environments (e.g., at disaster sites) is dangerous for humans. Hence, it is important to use teleoperated robots in such extreme environments. Because heavy lifting work is involved, hydraulic actuators with high output are more commonly used than electric actuators. Therefore, it is necessary to operate remotely controlled robots driven by hydraulic actuators. Bilateral control is remote control with a sense of force. Because most bilateral control systems have been studied mainly using electric actuators, bilateral control using hydraulic actuators is still a challenge. In this study, we propose placing a bilateral controller between an electric actuator on the master side and a hydraulic actuator on the slave side using position and velocity. The controller exhibits the dynamics of bilateral control systems using position and velocity. In addition, the control performance of conventional methods and that of the proposed method are compared and experimentally verified.

Design of bilateral control for force feedback in surgical robot

In robot assisted laparoscopic surgery using a commercialized robot, such as the da Vinci, surgeons have encountered problems, such as organ impairment, because they depend only on visual information. To solve these problems, a haptic system is required. Force feedback and a bilateral control system are essential for realizing a haptic teleoperation system. The use of a force/torque sensor for force feedback is difficult in a surgical robot instrument, but previous studies confirmed that the reaction force loaded on a surgical robot instrument can be estimated using a sliding perturbation observer (SPO)-based reaction force estimation method. This paper suggests a bilateral controller applying SPO based force estimation method to realize the possibility of a haptic function in a laparoscopic surgery robot system. In the suggested bilateral controller, the master control uses impedance control and the slave control uses a sliding mode control (SMC). A torque and force sensorless teleoperation system can be implemented using the suggested bilateral control structure through an experimental evaluation.

Micro-Macro Bilateral Control in Delta Robot

This paper presents new method to perform micro-macro bilateral control system in robot with non-linear kinematic property between task space and controllable space. An example is the parallel Delta Robot which is selected due to better interaction with human, light weight, fast movement and 3-dimension movement. The conventional micro-macro bilateral control using Hadamard matrix cannot achieve micro-macro bilateral properties of Delta Robot due to dimension shifting which leads to differences in both position and force space and loss of sensibility in haptic interface properties. The actual robot is built with design properties of low friction that reduce the complexity of dynamic model of Delta Robot. The controllable space or joint space is converted to task space using mathematic model. Moreover, the force applied on task space is estimated using sensorless force control system or disturbance observer and converted to task space by Andre Olsson’s dynamic model of Delta Robot.

Decoupled Bilateral Control Based on Modal Space Observer in Master‐Slave Systems with Different Masses

SUMMARYThis paper proposes a method of decoupled bilateral control based on a modal space observer. In a conventional bilateral control system, the structures of master‐slave systems are not considered. This paper shows that a force controller and a position controller in a bilateral control system interfere with each other when the structures of the master‐slave systems are different. In order to solve this problem, a bilateral control system based on a hybrid matrix has been proposed. However, the computational process for calculating the hybrid matrix becomes complicated as the numbers of degrees of freedom in the master‐slave systems increase. In the proposed method, a nominal equivalent mass matrix with respect to the modal space is used, and the interfering terms are estimated and compensated using a modal space observer. Therefore, a simple control structure is realized using the proposed method. The performance of the proposed method is compared to that of the conventional methods through simulations and experiments, and the validity of the proposed method is confirmed.

Method of Time‐Delay Compensation in Multi‐Degree‐of‐Freedom Bilateral Control Systems with Different Configurations

SUMMARYIn this paper, a time‐delay compensation method based on a work space communication disturbance observer (WCDOB) is proposed. Time delay degrades the stability of a control system. A communication disturbance observer (CDOB) has been proposed to solve this problem. However, CDOB cannot compensate for time delay in multi‐degree‐of‐freedom bilateral control systems with different configurations, because the inertia of the robots is not fixed. In contrast, WCDOB can estimate the time delay based on work space information and compensate for them. The experimental results confirm the validity of the proposed method.

2ステージアクチュエータを用いた広帯域バイラテラル制御

This paper proposes a two-stage actuator system that consists of a coarse actuator driven by a ball screw with an AC motor (the first stage) and a fine actuator driven by a voice coil motor (the second stage). The proposed two-stage actuator system is applied to make a wide-bandwidth bilateral control system without needing expensive high-performance actuators. In the proposed system, the first stage has a wide moving range with a narrow control bandwidth, and the second stage has a narrow moving range with a wide control bandwidth. By consolidating these two inexpensive actuators with different control bandwidths in a complementary manner, a wide bandwidth bilateral control system can be constructed based on a mechanical impedance control. To show the validity of the proposed method, a prototype of the two-stage actuator system has been developed and basic performance was evaluated by experiment. The experimental results showed that a light mechanical impedance with a mass of 10 g and a damping coefficient of 2.5 N/(m/s) that is an important factor to establish good transparency in bilateral control has been successfully achieved and also showed that a better force and position responses between a master and slave is achieved by using the proposed two-stage actuator system compared with a narrow bandwidth case using a single ball screw system.

Realization of Simultaneity in Bilateral Control System under Communication Delay

Realization of Simultaneity in Bilateral Control System under Communication Delay

むだ時間を有するバイラテラル制御系のマスタ位置制御器設計法

A time delay between a master robot and slave robot degrades the stability of a bilateral control system. Thus, this paper presents an analysis on the relations between the position controller's gain on the master side, the control performance, and the stability. The analytical results showed that the stability is guaranteed when the gain is equal to the stiffness of the contact object. Accordingly, an adaptive controller that dynamically determines the gain depending on the stiffness was designed. The validity of the adaptive controller was verified through simulations and experiments.

A Two Flow Expression Method of Four-Channel Bilateral Control System with Time Delay and Validation of Model-Free Time Delay Compensator

A Two Flow Expression Method of Four-Channel Bilateral Control System with Time Delay and Validation of Model-Free Time Delay Compensator

A Structural Approach to Improve the Stability of Bilateral Control System with Time Delay

A Structural Approach to Improve the Stability of Bilateral Control System with Time Delay

Development of Flexible Displacement Sensor Using Ultrasonic Sensor for Flexible Pneumatic Robot Arm

In our previous study, the flexible robot arm using the flexible pneumatic cylinders for human wrist rehabilitation was proposed and tested. The low-cost bilateral control system using two embedded controller and tested robot arm was also proposed and tested. In this paper, to miniaturize the displacement measuring system and reduce its cost, the flexible and compact displacement sensor using the ultrasonic sensor is proposed. The measuring characteristics of the tested sensor are investigated. As a result, the flexible displacement sensor with the resolution of about 0.1mm and the measuring sampling period of about 4ms could be realized.

Motion Expression by Elemental Separation of Haptic Information

This study aims to reveal the concealed features of human motions. For this purpose, a method of elemental separation (ES method) of human motions is proposed. First, human motions are extracted as haptic information through a bilateral control system. Then, by using the proposed method, the haptic information is divided into basic elements: 1) transformation matrices; 2) hybrid angles; 3) pure position commands; and 4) pure force commands. The proposed method is validated through simulations as well as experiments with robotic and human operators. The obtained results clearly reveal the features of human motions, although it is difficult to recognize the differences from the original responses. Nonetheless, this study provides a motion expression that should contribute toward a greater understanding of human skill.

RTOS based embedded controller implementation of a bilateral control system

The Journal of the National Science Foundation of Sri Lanka publishes the results of research in all aspects of Science and Technology. The journal also has a website at http://www.nsf.gov.lk/. 2021 Impact Factor: 0.682The JNSF provides immediate open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge.Cover :Leatherback (a), green (b - adult & f - hatchling), hawksbill (c) and olive ridley (d) turtles who nest in Sri Lankan beaches, green turtle crawl marks (e) and by-catch of sea turtles in fisheries (c & d)Photo credits: SJ Perera (a & c), WPN Perera (b & e), K Ekaratne (d & f)

복강경 수술 로봇의 힘 반향을 위한 임피던스 모델 기반의 양방향 제어

LAS (Laparoscopy Assisted Surgery) has been substituted alternatively for traditional open surgery. However, when using a commercialized robot assisted laparoscopic such as Da Vinci, surgeons have encountered some problems due to having to depend only on information by visual feedback. To solve this problem, a haptic function is required. In order to realize the haptic teleoperation system, a force feedback and bilateral control system are needed. Previous research showed that the perturbation value estimated by a SPO (Sliding Perturbation Observer) followed a reaction force that loaded on the surgical robot instrument. Thus, in this paper, the force feedback problem of surgical robots is solved through the reaction force estimation method. This paper then introduces the possibility of the haptic function realization of a laparoscopic surgery robot using a bilateral control system. For bilateral control, the master uses an impedance control and the slave uses a SMC (Sliding Mode Control). The experiment results show that a torque and force sensorless teleoperation system can be implemented using a bilateral control structure.