Design and Validation of A Novel Planar 2R1T Remote Center-of-motion Mechanism Composing of Dual-Triangular and Straight-Line Linkages

2021 ◽  
pp. 1-11
Author(s):  
Genliang Chen ◽  
Yuanhao Xun ◽  
Yuchen Chai ◽  
Siyue Yao ◽  
Chao Chen ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Degrees Of Freedom ◽  
Fast Recovery ◽  
Positioning Accuracy ◽  
Motion Mechanism ◽  
Small Incision ◽  
Pure Rotation ◽  
Differential Motion ◽  
Straight Line ◽  
Motion Characteristics

Abstract Benefiting from small incision and fast recovery, minimally invasive surgeries (MIS) exhibit great advantages in clinical operations. In such kind of surgeries, the remote center-of-motion (RCM) mechanisms play an important role owing to their special motion characteristics. This paper presents the design of a novel planar RCM mechanism of two rotational and one translational degrees-of-freedom. In the proposed design, the mobility of RCM mechanisms is decomposed into one-DOF pure rotation and translation with a remote stationary point. The dual-triangular linkage and the Peaucellier-Lipkin straight-line linkage are introduced to achieve the remote rotation and translation, respectively. Inspired by the concept of virtual screw, a dual-helical differential-motion joint is particularly designed to generate the coaxial rotation and translation. A preliminary prototype is developed to validate the feasibility of the designed RCM mechanism. The experimental results show that the developed prototype is easy to control and of acceptable positioning accuracy, which manifests potential application in MIS.

Design and Kinematic Optimization of a Two Degrees-of-Freedom Planar Remote Center of Motion Mechanism for Minimally Invasive Surgery Manipulators

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Sajid Nisar ◽  
Takahiro Endo ◽  
Fumitoshi Matsuno
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Degrees Of Freedom ◽  
Mechanical Design ◽  
Motion Mechanism ◽  
Close Proximity ◽  
Kinematic Optimization ◽  
Surgical Manipulator ◽  
Multiple Manipulators

Minimally invasive surgery (MIS) requires four degrees-of-freedom (DOFs) (pitch, translation, yaw, and roll) at the incision point, but the widely used planar remote center of motion (RCM) mechanisms only provide one degree-of-freedom. The remaining three DOFs are achieved through external means (such as cable-pulleys or actuators mounted directly on the distal-end) which adversely affect the performance and design complexity of a surgical manipulator. This paper presents a new RCM mechanism which provides the two most important DOFs (pitch and translation) by virtue of its mechanical design. Kinematics of the new mechanism is developed and its singularities are analyzed. To achieve maximum performance in the desired workspace region, an optimal configuration is also evaluated. The design is optimized to yield maximum manipulability and tool translation with smallest size of the mechanism. Unlike the traditional planar RCM mechanisms, the proposed design does not rely on external means to achieve translation DOF, and therefore, offers potential advantages. The mechanism can be a suitable choice for surgical applications demanding a compact distal-end or requiring multiple manipulators to operate in close proximity.

Conceptual Design of an Exactly Straight Lifting Forging Manipulator

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Huafeng Ding ◽  
Zemin Feng ◽  
Hongye Fu ◽  
Yuanyuan Wang
Keyword(s):  
Bearing Capacity ◽  
Conceptual Design ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Coordinated Control ◽  
High Load ◽  
Load Bearing Capacity ◽  
Motion Mechanism ◽  
Straight Line ◽  
Forging Manipulator

The gripper lifting track of a forging manipulator should keep as close to a straight line as possible, especially for the manufacturing of long or high-precision forged pieces. However, the lifting tracks of most forging manipulators are arc, such as DANGO & DIENENTHAL in Siegen (DDS) and Schloemann-SiemagAG Meer (SMS Meer). This paper proposes a new forging manipulator whose gripper lifting track is exactly a straight line. First, a planar 3-degrees-of-freedom (3-DOF) mechanism whose gripper moves along a straight line is proposed. Second, replace the lifting drive of the planar mechanism with a parallel mechanism which only generates one translation, and obtain a major-motion mechanism. Finally, a new forging manipulator is constructed based on this major-motion mechanism. The new manipulator has the advantages of exactly straight lifting, high load-bearing capacity, and decoupling the lifting from other motions. It not only can improve forging precision for long axial forged pieces but also make coordinated control of two forging manipulators much easier.

A New Type of Planar Two Degree-of-Freedom Remote Center-of-Motion Mechanism Inspired by the Peaucellier–Lipkin Straight-Line Linkage

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Genliang Chen ◽  
Jiepeng Wang ◽  
Hao Wang
Keyword(s):  
Minimally Invasive ◽  
Degree Of Freedom ◽  
Risk Of Infection ◽  
Fast Recovery ◽  
Robot Assisted ◽  
Straight Line ◽  
Control Scheme ◽  
Potential Applicability ◽  
New Type ◽  
Two Degree Of Freedom

Benefiting from small incisions, reduced risk of infection, less pain, and fast recovery, minimally invasive surgery has shown tremendous advantages for patients. In these kinds of procedures, remote center-of-motion (RCM) mechanisms play an important role in performing operations through small incisions. Inspired by the Peaucellier–Lipkin straight-line cell, this paper presents the design and verification of a new type of planar two degree-of-freedom (DOF) RCM mechanism. A synthesized planar RCM mechanism is realized by a symmetric linkage actuated by two circular motion generators. The main merit of the proposed 2DOF RCM mechanism is its straightforward kinematics, which results in a simple control scheme. One of the candidate mechanisms, which is simple in structure and easy to fabricate, is intensively investigated. A prototype was built, on which preliminary experiments have been conducted, to verify the feasibility of the proposed new mechanism. The experimental results show that the fabricated 2DOF prototype has a nearly stationary remote center of motion. Therefore, the prototype has potential applicability in robot-assisted minimally invasive surgeries.

scholarly journals Huber-Based Robust Unscented Kalman Filter Distributed Drive Electric Vehicle State Observation

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 750
Author(s):  
Wenkang Wan ◽  
Jingan Feng ◽  
Bao Song ◽  
Xinxin Li
Keyword(s):  
Kalman Filter ◽  
Real Time ◽  
Degrees Of Freedom ◽  
Unscented Kalman Filter ◽  
State Parameter ◽  
State Observation ◽  
Straight Line ◽  
Distributed Drive Electric Vehicle ◽  
Huber Method ◽  
Yaw Moment

Accurate and real-time acquisition of vehicle state parameters is key to improving the performance of vehicle control systems. To improve the accuracy of state parameter estimation for distributed drive electric vehicles, an unscented Kalman filter (UKF) algorithm combined with the Huber method is proposed. In this paper, we introduce the nonlinear modified Dugoff tire model, build a nonlinear three-degrees-of-freedom time-varying parametric vehicle dynamics model, and extend the vehicle mass, the height of the center of gravity, and the yaw moment of inertia, which are significantly influenced by the driving state, into the vehicle state vector. The vehicle state parameter observer was designed using an unscented Kalman filter framework. The Huber cost function was introduced to correct the measured noise and state covariance in real-time to improve the robustness of the observer. The simulation verification of a double-lane change and straight-line driving conditions at constant speed was carried out using the Simulink/Carsim platform. The results show that observation using the Huber-based robust unscented Kalman filter (HRUKF) more realistically reflects the vehicle state in real-time, effectively suppresses the influence of abnormal error and noise, and obtains high observation accuracy.

Design and Analysis of Motion Mechanism Driven by Several IDMs in Parallel

2012 ◽  
Vol 197 ◽  
pp. 55-59 ◽  
Author(s):  
Nan Jiang ◽  
Jun Biao Liu
Keyword(s):  
Degrees Of Freedom ◽  
Design Method ◽  
Piezo Actuator ◽  
Motion Mechanism ◽  
Spherical Motor ◽  
Drive Mechanism ◽  
Follow Up Study ◽  
Analysis Of Motion

As a kind of piezo actuator, impact drive mechanism (IDM) has advantages in precision machinery and instruments. Several IDMs are used in parallel to realize some motion mechanisms which have multi degrees of freedom (DOF). Two motion mechanisms are designed subsequently, and a spherical motor is designed and assembled in principle based on one of them. Experiment results reveal that this design method is feasible, but some problems exist, for example, vibration is serious. These problems should be solved in follow-up study.

Kinematics of a Fully-Decoupled Remote Center-of-Motion Parallel Manipulator for Minimally Invasive Surgery

2012 ◽  
Vol 6 (2) ◽  
Author(s):  
Chin-Hsing Kuo ◽  
Jian S. Dai
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Surgical Instruments ◽  
End Effector ◽  
Minimally Invasive Surgical ◽  
Inverse Kinematics Problem

A crucial design challenge in minimally invasive surgical (MIS) robots is the provision of a fully decoupled four degrees-of-freedom (4-DOF) remote center-of-motion (RCM) for surgical instruments. In this paper, we present a new parallel manipulator that can generate a 4-DOF RCM over its end-effector and these four DOFs are fully decoupled, i.e., each of them can be independently controlled by one corresponding actuated joint. First, we revisit the remote center-of-motion for MIS robots and introduce a projective displacement representation for coping with this special kinematics. Next, we present the proposed new parallel manipulator structure and study its geometry and motion decouplebility. Accordingly, we solve the inverse kinematics problem by taking the advantage of motion decouplebility. Then, via the screw system approach, we carry out the Jacobian analysis for the manipulator, by which the singular configurations are identified. Finally, we analyze the reachable and collision-free workspaces of the proposed manipulator and conclude the feasibility of this manipulator for the application in minimally invasive surgery.

Mechanical Manipulator for Intuitive Control of Endoscopic Instruments With Seven Degrees of Freedom

2004 ◽  
Author(s):  
J. E. N. Jaspers ◽  
M. Shehata ◽  
F. Wijkhuizen ◽  
J. L. Herder ◽  
C. A. Grimbergen
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Degrees Of Freedom ◽  
Force Feedback ◽  
Robotic Systems ◽  
Complex Tasks ◽  
Steel Wires

Performing complex tasks in Minimally Invasive Surgery (MIS) is demanding due to a disturbed hand-eye co-ordination, the use of non-ergonomic instruments with limited degrees of freedom (DOFs) and a lack of force feedback. Robotic telemanipulatory systems enhance surgical dexterity by providing up to 7 DOFs. They allow the surgeon to operate in an ergonomically favorable position with more intuitive manipulation of the instruments. Commercially available robotic systems, however, are very bulky, expensive and do not provide any force feedback. The aim of our study was to develop a simple mechanical manipulator for MIS. When manipulating the handle of the device, the surgeon’s wrist and grasping movements are directly transmitted to the deflectable instrument tip in 7 DOFs. The manipulator consists of a parallelogram mechanism with steel wires. First phantom experience indicated that the system functions properly. The MIM provides some force feedback improving safety. A set of MIMs seems to be an economical and compact alternative for robotic systems.

LOWER LIMB REHABILITATION ROBOT FOR GAIT TRAINING

2014 ◽  
Vol 14 (06) ◽  
pp. 1440004 ◽  
Author(s):  
SHUAI GUO ◽  
JIANCHENG JI ◽  
GUANGWEI MA ◽  
TAO SONG ◽  
JING WANG
Keyword(s):  
Lower Limb ◽  
Degrees Of Freedom ◽  
Balance Training ◽  
Gait Training ◽  
Rehabilitation Robot ◽  
Stroke Patients ◽  
Motion Characteristics ◽  
Set Up ◽  
Limb Rehabilitation ◽  
Lower Limb Rehabilitation

After analyzing the rehabilitation needs of stroke patients and the previous studies on lower limb rehabilitation robot, our lower limb rehabilitation robot is designed for stroke patients' gait and balance training. The robot consists of the mobile chassis, the support column and the pelvis mechanism and it is described in detail. As the pelvis mechanism allows most of the patient's motion degrees of freedom (DOFs), the kinematics model of the mechanism is set up, and kinematics simulation is carried out to study the motion characteristics of the mechanism. After analyzing the calculation and simulation results, the pelvis mechanism is proven to measure up to the movement needs of the paralytic's waist and pelvis in walking rehabilitation process.

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