Slave Manipulator Research Articles

Development of Master-Slave Surgical Robot System with Heartbeat Synchronization Mechanism (Evaluation of Position Synchronization Performance and Synchronization Suture Operability)

In this paper, a master-slave surgical robot system with heartbeat synchronization mechanism for off-pump CABG suturing operation is developed. This robot system is composed of a master manipulator, a slave manipulator, a heartbeat sensing system and a compact flexible endoscope system. The heartbeat sensing system measures 6 DOF heartbeat motion in real-time. The position of the slave manipulator is controlled as synchronizing with heartbeat. The compact flexible endoscope is fixed to a heart using a soft coupling which is used in medical case, so that the relative position between a heart and the compact flexible endoscope is maintained constant. Moreover, the surgical robot system is controlled in master-slave control method for surgeon's tele-operation. Therefore this system is able to perform surgical procedure while the system synchronizes with the heartbeat. In order to evaluate the performance of the system, the synchronization ability test, the master-slave operation test in vivo, and the performance of suturing operation under synchronization were conducted. In the result of the first test, it was showed that the maximum error between desired position and experimental position in the synchronization control was less than 1mm. In the second test, it was confirmed that the system was able to suture a pericardia, which was not beating. In the third test, it became clear that the maximum error between the desired position and experimental position was less than 1.24 to 2mm and the system was able to suture an isolated tissue which was driven by a robotic heartbeat phantom in 1Hz.

A Remotely Operable Facility for Fabrication of Fuel Pins for test Irradiation

A laboratory scale facility has been set up for fabrication of test fuel pins through sol-gel route for irradiation in FBTR, Kalpakkam. The facility is a train of glove boxes fitted with master slave manipulators for carrying out various operations involved in the fuel fabricat ion process. The paper describes the design features of the equipment and mechanisms for automation, developed for microsphere production and other processes. The design features include control system and vision systems for man- machine interface.

Passivity Based Control of Bilateral Teleoperators with Time Delay using Low-Pass Filters

AbstractBilateral teleoperators, designed within the passivity framework using the concepts of scattering transformation and two port network theory, provide robust stability in the constant delay condition in a network. In this paper, we propose a new coordination architecture for bilateral teleoperation in which static feedback gains in the master and slave robots are replaced by dynamic feedbacks using nonlinear low-pass filters. This architecture can select low-frequency gain and high-frequency gain independently. We can select the cut-off frequencies of the master block and slave block independently. We show the stability of our system and the ultimate boundedness of the position error between the master manipulator and the slave manipulator trajectories using a Lyapunov Krasovskii functional, in free motion with transmission time delay. This architecture guarantees accurate position tracking of the two robots in free motion with transmission time delay. Simulation results are presented that demonstrate the effectiveness of the proposed architecture for position and force tracking control.

1P1-A06 スレーブマニピュレータ用多軸ロボットコントローラの開発(岡山発のロボティクス・メカトロニクス技術と産学官連携)

1P1-A06 スレーブマニピュレータ用多軸ロボットコントローラの開発(岡山発のロボティクス・メカトロニクス技術と産学官連携)

Adaptive sliding mode control of a piezo-actuated bilateral teleoperated micromanipulation system

Abstract Piezoelectric actuators are widely used in micro manipulation applications. However, hysteresis nonlinearity limits the accuracy of these actuators. This paper presents a novel approach for utilizing a piezoelectric nano-stage as the slave manipulator of a teleoperation system based on a sliding mode controller. The Prandtl–Ishlinskii (PI) model is used to model actuator hysteresis in feedforward scheme to cancel out this nonlinearity. The presented approach requires full state and force measurements at both the master and slave sides. Such a system is costly and also difficult to implement. Therefore, sliding mode unknown input observer (UIO) is proposed for full state and force estimations. Furthermore, the effects of uncertainties in the constant parameters on the estimated external forces should be eliminated. So, a robust adaptive controller is proposed and its stability is guaranteed through the Lyapunov criterion. Performance of the proposed control architecture is verified through experiments.

Development of a Force‐Reflecting Robotic Platform for Cardiac Catheter Navigation

Electrophysiological catheters are used for both diagnostics and clinical intervention. To facilitate more accurate and precise catheter navigation, robotic cardiac catheter navigation systems have been developed and commercialized. The authors have developed a novel force-reflecting robotic catheter navigation system. The system is a network-based master-slave configuration having a 3-degree of freedom robotic manipulator for operation with a conventional cardiac ablation catheter. The master manipulator implements a haptic user interface device with force feedback using a force or torque signal either measured with a sensor or estimated from the motor current signal in the slave manipulator. The slave manipulator is a robotic motion control platform on which the cardiac ablation catheter is mounted. The catheter motions-forward and backward movements, rolling, and catheter tip bending-are controlled by electromechanical actuators located in the slave manipulator. The control software runs on a real-time operating system-based workstation and implements the master/slave motion synchronization control of the robot system. The master/slave motion synchronization response was assessed with step, sinusoidal, and arbitrarily varying motion commands, and showed satisfactory performance with insignificant steady-state motion error. The current system successfully implemented the motion control function and will undergo safety and performance evaluation by means of animal experiments. Further studies on the force feedback control algorithm and on an active motion catheter with an embedded actuation mechanism are underway.

Workspace control system of underwater tele-operated manipulators on an ROV

This paper presents a control technique for structured undersea tasks that require a high degree of precision. The overall efficiency of tele-operated underwater manipulation is improved by reducing the burden on the human operator. A new workspace-control system composed of a computer and input devices in workspace was developed to support the operator. The computer transforms the desired velocity of end-effector in workspaces to desired joint angles by solving the inverse kinematics of the slave manipulators. The desired joint angles are transferred to the slave controller through RS-485 serial communication, and be followed by the slave manipulator. The developed master system provides advantages in conducting structured tasks(coring, drilling, underwater connector mating, etc.) that require precise control of the end-effector’s motion and attitude. The existing master system, however, is more useful for unstructured tasks than newly developed master system. By combining the two master systems, the work efficiency of the underwater tele-operated manipulator system was improved. This paper presents the development of the workspace-control system and a working strategy to alleviate operator’s burden in underwater works. Experimental results are presented to evaluate the effectiveness of the proposed method using underwater manipulators mounted on the KORDI deep-sea ROV Hemire.

Design of a master and slave transluminal endoscopic robot for natural orifice transluminal endoscopic surgery

Natural orifice transluminal endoscopic surgery (NOTES) is an endoscopic surgical intervention technique for treatment within the intraperitoneal cavity, which utilizes natural orifices (i.e. mouth, vagina, anus, etc.) as the entry point. In line with minimally invasive surgery (MIS), NOTES aims to perform surgical procedures without skin incisions, thus eliminating unsightly scars. In this article, a master—slave robotic system is proposed to enable the endoscopist to perform demanding NOTES procedures, which are currently performed by surgeons in an opened or keyhole surgery setting. The robotic system consists of a master console and slave manipulators driven by tendon—sheath actuation. Force prediction at the slave end is also introduced in this article to provide force feedback to the surgeon. Using the developed robotic system, liver wedge resection has been conducted in animal trials with promising results.

Achievement of chaotic synchronization trajectories of master–slave manipulators with feedback control strategy

This paper addresses a master–slave synchronization strategy for complex dynamic systems based on feedback control. This strategy is applied to 3-DOF planar manipulators in order to obtain synchronization in such complicated as chaotic motions of end-effectors. A chaotic curve is selected from Duffing equation as the trajectory of master end-effector and a piecewise approximation method is proposed to accurately represent this chaotic trajectory of end-effectors. The dynamical equations of master–slave manipulators with synchronization controller are derived, and the Lyapunov stability theory is used to determine the stability of this controlled synchronization system. In numerical experiments, the synchronous motions of end-effectors as well as three joint angles and torques of master–slave manipulators are studied under the control of the proposed synchronization strategy. It is found that the positive gain matrix affects the implementation of synchronization control strategy. This synchronization control strategy proves the synchronization’s feasibility and controllability for complicated motions generated by master–slave manipulators.

Natural orifice transgastric endoscopic wedge hepatic resection in an experimental model using an intuitively controlled master and slave transluminal endoscopic robot (MASTER)

The lack of triangulation of standard endoscopic devices limits the degree of freedom for surgical maneuvers during natural orifice transluminal endoscopic surgery (NOTES). This study explored the feasibility of adapting an intuitively controlled master and slave transluminal endoscopic robot (MASTER) the authors developed to facilitate wedge hepatic resection in NOTES. The MASTER consists of a master controller, a telesurgical workstation, and a slave manipulator that holds two end-effectors: a grasper, and a monopolar electrocautery hook. The master controller is attached to the wrist and fingers of the operator and connected to the manipulator by electrical and wire cables. Movements of the operator are detected and converted into control signals driving the slave manipulator via a tendon-sheath power transmission mechanism allowing nine degrees of freedom. Using this system, wedge hepatic resection was performed through the transgastric route on two female pigs under general anesthesia. Entry into the peritoneal cavity was via a 10-mm incision made on the anterior wall of the stomach by the electrocautery hook. Wedge hepatic resection was performed using the robotic grasper and hook. Hemostasis was achieved with the electrocautery hook. After the procedure, the resected liver tissue was retrieved through the mouth using the grasper. Using the MASTER, transgastric wedge hepatic resection was successfully performed on two pigs with no laparoscopic assistance. The entire procedure took 9.4 min (range, 8.5-10.2 min), with 7.1 min (range, 6-8.2 min) spent on excision of the liver tissue. The robotics-controlled device was able to grasp, retract, and excise the liver specimen successfully in the desired plane. This study demonstrated for the first time that the MASTER could effectively mitigate the technical constraints normally encountered in NOTES procedures. With it, the triangulation of surgical tools and the manipulation of tissue became easy, and wedge hepatic resection could be accomplished successfully without the need for assistance using laparoscopic instruments.

Precision control of a piezo-actuated micro telemanipulation system

Piezoelectric actuators are widely used in micro manipulation applications. However hysteresis nonlinearity limits accuracy of these actuators. This paper presents a novel approach for utilizing a piezoelectric nano-stage as slave manipulator of a teleoperation system. The Prandtl-Ishlinskii (PI) model is used to model actuator hysteresis in feedforward scheme to cancel out this nonlinearity. To deal with the influence of parametric uncertainties, unmodeled dynamics, and PI identification error a perturbation term is added to the slave model and apply a sliding mode based impedance control with perturbation estimation. The stability of the entire system is guaranteed by Llewellyn’s absolute stability criterion. Performance of the proposed controllers is verified through experiments.

Development of a Master–Slave System with Force-Sensing Abilities using Pneumatic Actuators for Laparoscopic Surgery

In minimally invasive telesurgical systems, displaying the forces measured at the slave side is an important issue. The ability to accurately feel the force being applied at the slave side is important. This paper describes a slave manipulator, which has 7 d.o.f. and is driven by pneumatic actuators, newly designed and developed for use in minimally invasive surgery. Then, a master–slave system is constructed using the master device we have developed. In the system, we applied a different impedance control for each manipulator. We adopted a force-control type of impedance control without a force sensor for the pneumatic slave manipulator. For the master manipulator, we used a motion-control type of impedance control. The experimental results indicate that the operator feels the force at the slave side with an uncertainty of about 1.5 N. The effectiveness of the force feedback using the developed system is demonstrated.

2A1-E03 操作性と操作感の両立を実現する人間機械協調系のための操作支援制御 : マスタスレーブシステムによる柔軟物搬送作業のための操作支援制御

This study discusses an assist control method for human-machine-cooperative system. The assist control method should be designed so as to increase both maneuverability and opeating feel. This paper presents an assist control method for flexible parts conveyance using master slave manipulators. The maneuverability and the operating feel are evaluated quantitatively on the basis of task achievement time and maximum differential value of operational force respectively. Its effectiveness was verified experimentally by six beginner trials.

Design and Implementation of a Compact Master-Slave Robotic System with Force Feedback and Energy Recycling

Master-slave control is becoming increasingly popular in the development of robotic systems which can provide rehabilitation training for hemiplegic patients with a unilaterally disabled limb. However, the system structures and control strategies of existent master-slave systems are always complex. An innovative master-slave system implementing force feedback and motion tracking for a rehabilitation robot is presented in this paper. The system consists of two identical motors with a wired connection, and the two motors are located at the master and slave manipulator sites respectively. The slave motor tracks the motion of the master motor directly driven by a patient. As well, the interaction force produced at the slave site is fed back to the patient. Therefore, the impaired limb driven by the slave motor can imitate the motion of the healthy limb controlling the master motor, and the patient can regulate the control force of the healthy limb properly according to the force sensation. The force sensing and motion tracking are achieved simultaneously with neither force sensors nor sophisticated control algorithms. The system is characterized by simple structure, bidirectional controllability, energy recycling, and force feedback without a force sensor. Test experiments on a prototype were conducted, and the results appraise the advantages of the system and demonstrate the feasibility of the proposed control scheme for a rehabilitation robot.

マスタスレーブマニピュレータによる柔軟物の搬送位置決め作業のための操作支援制御と評価(機械力学,計測,自動制御)

マスタスレーブマニピュレータによる柔軟物の搬送位置決め作業のための操作支援制御と評価(機械力学,計測,自動制御)

An adaptive controller for nonlinear teleoperators

In Chopra et al (2008) [Chopra, N., Spong, M. W., & Lozano, R. (2008). Synchronization of bilateral teleoperators with time-delay. Automatica, 44(8), 2142–2148], an adaptive controller for teleoperators with time-delays, which ensures synchronization of positions and velocities of the master and slave manipulators, and does not rely on the use of the ubiquitous scattering transformation, is proposed. In this paper it is shown that this controller will tend to drive to zero the positions of the joints where gravity forces are non-zero. Hence, the scheme is, in general, applicable only to systems without gravity. We also prove in this paper that this limitation can be obviated, replacing the positions and velocities–that are used in the coordinating torques and the adaptation laws–by their errors. Simulation results illustrate the performance of both schemes.

Description of Instantaneous Restriction Space for Multi-DOFs Bilateral Teleoperation Systems Using Position Sensors in Unstructured Environments

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper investigates a novel position-sensor-based force reflection framework for multi-degree-of-freedom (DOF) bilateral teleoperation systems in unstructured environments. The conventional position-sensor-based force reflection method, which is known as position error feedback, may generate grossly inaccurate force reflection directions during collisions involving the slave manipulator links. The proposed restriction space projection framework calculates the instantaneous restriction space to provide the accurate force reflection, regardless of kinematic dissimilarity (KDS) conditions of bilateral teleoperation systems. Simulation results confirmed the validity of the proposed framework in a KDS bilateral teleoperation system under various constraint conditions. </para>

Construction Methodology for a Remote Ultrasound Diagnostic System

In the present paper, we describe a method for constructing a remote ultrasound diagnostic system. Remote diagnosis can be realized using a communication network. We have developed a master-slave type remote medical system to diagnose shoulder diseases, such as dialysis-related amyloid arthropathy (DRAA), by ultrasonographic images. Proper positioning, orientation, and contact force between the ultrasound probe and the affected area of the patient are required in order to acquire proper diagnostic images. Safety and manipulability are also required when operating the remote medical system through a communication network. Therefore, the system has impedance control capability for positioning of the master and slave manipulators in order to convey the contact force and enhance manipulability. In addition, the system has continuous-path control capability for the orientation of the slave manipulator in order to realize smooth and accurate motion of the ultrasound probe, even if the sampling rate of the transmission of the orientation data of the master manipulator is not sufficient. The results of remote diagnostic experiments demonstrated that a healthcare professional could diagnose real patients through a communication network using the constructed system.

Natural Orifice Trangastric Endoscopic Segmental Hepatectomy Using a Through-the-Scope Intuitively Controlled Robotics-Enhanced Manipulator System

Background and Aims: The parallelism of standard endoscopic fixtures limits the degree of freedom for surgical maneuvers during Natural Orifice Transluminal Endoscopic Surgery (NOTES). This study explored the feasibility of adapting an intuitively-controlled robotics-enhanced endosurgical system we developed to facilitate hepatectomy in NOTES. Methods: The system comprises a master controller, a telesurgical workstation, and a slave robotic manipulator. The master is attached to the wrists and fingers of the operator through an array of sensors and joints. The slave comprises 2 manipulators - a grasper and a mono-polar cautery hook which are separately inserted through the operating channels (2.8 mm, 3.7 mm diameters) of a gastroscope. Movements of the operator detected by sensors are actuated into force signals to drive the manipulators via a tendon-sheath mechanism. The procedure was performed on a 35 kg female pig under general anesthesia. The gastroscope with robotic manipulators was passed into the stomach via an overtube. Entry into the peritoneal cavity was made through a 10 mm incision on the anterior wall of the stomach. Access to the liver segment was made by retroflexing the endoscope at a 45 degrees angle. Segmental hepatectomy was performed using the grab and cut functions of the robotic grasper and hook, respectively. Hemostasis was achieved with the hook. Gastrotomy was left open and the animal was euthanized. Results: Transgastric segmental hepatectomy was successfully performed using the robotic system with no laparoscopic assistance. The entire operation was completed in 8.5 min, with 2.5 min spent on gastrotomy and endoscopic access to target site, and 6 min spent on excision of the liver segment. The robotic grasper was able to effectively grab and retract the liver while the cautery hook dissected the liver. Coordination of the two end-effectors was precise and triangulation of the two manipulating arms was achieved with ease. The liver segment, which was excised in one piece, measured 21 × 10 × 7.6 mm. Parenchymal bleeding was adequately controlled by electrocautery using the hook, and this was achieved in 1.2 min. The resected liver segment was retrieved whole through the open gastrotomy and removed through the mouth using the grasper. Conclusion: This study demonstrated for the first time the through-the-scope robotics-enhanced endosurgical system could effectively mitigate the technical constraints normally encountered in NOTES procedures. With it, the triangulation of surgical tools and manipulation of tissue become easy and the entire operation could be successfully accomplished without the need of laparoscopic assistance.

Bridge transported servo manipulator system for remote handling tasks under a radiation environment

PurposeThis paper aims to describe bridge transported servo‐manipulator (BTSM) system, which was developed to overcome the limited workspace of the conventional mechanical master‐slave manipulators in a hot cell.Design/methodology/approachThe BTSM system consists of four components: a transporter with a telescoping tubeset, a slave manipulator, a master manipulator, and a remote control system. The slave manipulator is able to move horizontally, transversely, and vertically by using the transporter.FindingsThe performance test of the BTSM system has been carried out in terms of basic functions such as force threshold, bilateral control and force reflection characteristic.Originality/valueWith respect to design characteristic, the BTSM system has the novel features in that the individual motor modules or the slave manipulator can be repaired in a fully remote manner in case of catastrophic failure. Also, a 3D viewing camera facilitates remote tasks giving human operators realistic environmental information.