scholarly journals Periodic and Chaotic Motions of a Two-Bar Linkage with OPCL Controller

2010 ◽  
Vol 2010 ◽  
pp. 1-15 ◽  
Author(s):  
Qingkai Han ◽  
Xueyan Zhao ◽  
Xiaoguang Yang ◽  
Bangchun Wen
Keyword(s):  
Control Method ◽  
Surrogate Data ◽  
External Input ◽  
Dynamical Equations ◽  
Robot System ◽  
Chaotic Motions ◽  
Performance Control ◽  
System Parameters ◽  
Robot Performance ◽  
Nonlinear Behaviors

A two-bar linkage, which is described in differential dynamical equations, can perform nonlinear behaviors due to system parameters or external input. As a basic component of robot system, the investigation of its behavior can improve robot performance, control strategy, and system parameters. An open-plus-close-loop (OPCL) control method therefore is developed and applied to reveal and classify the complicated behaviors of a two-bar linkage. In this paper, the conception and stability of OPCL are addressed firstly. Then it is applied to the dynamical equations of two-bar linkage. Different motions including single-periodic, multiple-periodic, quasiperiodic, and chaotic motions are unfolded by numerical simulations when changing the controller parameters. Furthermore, the obtained chaotic motions are sorted out for qualitative and quantificational study using Lyapunov exponents and hypothetic possibilities of surrogate data method.

scholarly journals Design of a Laparoscopic Robot System Based on Spherical Magnetic Field

2019 ◽  
Vol 9 (10) ◽  
pp. 2070
Author(s):  
Hongxing Wei ◽  
Kaichao Li ◽  
Dong Xu ◽  
Wenshuai Tan
Keyword(s):  
Magnetic Field ◽  
Control Method ◽  
Open Loop ◽  
Surgical Instruments ◽  
Prototype System ◽  
Single Incision Laparoscopic Surgery ◽  
Robot System ◽  
Surgical Incision ◽  
Spherical Motor ◽  
External Driving

In single incision laparoscopic surgery (SILS), because the laparoscope and other surgical instruments share the same incision, the interferences between them constrain the dexterity of surgical instruments and affect the field of views of the laparoscope. Inspired by the structure of the spherical motor and the driving method of an intraocular micro robot, a fully inserted laparoscopic robot system is proposed, which consists of an inner laparoscopic robot and external driving device. The position and orientation control of the inner laparoscopic robot are controlled by a magnetic field generated by the driving device outside the abdominal wall. The instrumental interferences can be alleviated and better visual feedback can be obtained by keeping the laparoscopic robot away from the surgical incision. To verify the feasibility of the proposed structure and explore its control method, a prototype system is designed and fabricated. The electromagnetism model and the mechanical model of the laparoscopic robot system are established. Finally, the translational, rotational, and deflection motion of the laparoscopic robot are demonstrated in practical experiment, and the accuracy of deflection motion of the laparoscopic robot is verified in open-loop condition.

Nonlinear dynamics of a spur gear pair with tooth root crack based on an amplitude modulation function

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nan Gao ◽  
Shiyu Wang ◽  
Muhammad Asad Ur Rehman Bajwa
Keyword(s):  
Nonlinear Dynamics ◽  
Amplitude Modulation ◽  
Spur Gear ◽  
Dynamic Mesh ◽  
Gear Pair ◽  
Mesh Stiffness ◽  
Chaotic Motions ◽  
Content Type ◽  
Modulation Function ◽  
Nonlinear Behaviors

PurposeGear transmissions are widely utilized in practice. This paper aims to uncouple the crack feature from the cracked time-varying mesh stiffness (TVMS) and investigate the effects of the crack on the nonlinear dynamics of a spur gear pair.Design/methodology/approachAn approximate method to simulate the cracked TVMS is proposed by using an amplitude modulation function. The ratio of mesh stiffness loss is introduced to estimate the TVMS with different crack depths and angles. The dynamic responses are obtained by solving a torsional model which takes the non-loaded static transmission error, the backlash and the cracked TVMS into account. By using the bifurcation diagram, the largest Lyapunov exponent (LLE) and dynamic mesh force, the influences of crack on nonlinear behaviors are examined. The dynamic characteristics are identified from the phase diagram, Poincaré map, dynamic mesh force, time series and FFT spectra.FindingsThe comparison between the healthy and cracked gear pairs indicates that the crack affects the system motions, such as the obvious changes of impact force and unpredictable instability. Besides, the additive and difference combination frequencies can be found in periodic-1 and -2 motions, but they are covered in periodic-3 and chaotic motions. Deeper crack is an important determinant of the nonlinear behaviors at a higher speed.Originality/valueThe research provides an interesting perspective on cracked TVMS and reveals the connection between crack and nonlinear behaviors of the gear pairs.

scholarly journals Multicriterial Evaluation of the Transport and Logistic System of the Moscow Region

2021 ◽  
Vol 334 ◽  
pp. 02029
Author(s):  
Vasily Demin ◽  
Alexey Terentyev
Keyword(s):  
Radio Frequency ◽  
Control Method ◽  
Complex Structure ◽  
Moscow Region ◽  
Logistics System ◽  
System Parameters ◽  
Complex Problems ◽  
Control Technologies ◽  
And Control

The article deals with the direction of solving complex problems of interaction between the elements of the transport and logistics system of the Moscow region as a complex structure of management methods in multi-criteria systems and technologies for monitoring the quality of processes. The control method should optimize the system parameters, and control technologies (radio frequency cargo identification) implement feedback in the system.

Self-Calibration of Push-Pull Solenoid Actuators in Electrohydraulic Valves

2004 ◽  
Author(s):  
Qing Hui Yuan ◽  
Perry Y. Li
Keyword(s):  
Mechanical Property ◽  
Parameter Identification ◽  
Simulation Study ◽  
Electromagnetic Force ◽  
High Performance ◽  
Calibration Procedure ◽  
Performance Control ◽  
System Parameters ◽  
Self Calibration ◽  
Solenoid Actuator

System parameters for solenoid actuators are important for high performance control and for self-sensing. Due to the non-linearities in the solenoid actuators, parameter identification procedures that aim to obtain the electro-mechanical property can be complex and time consuming. In this paper, a self-calibration procedure for solenoid actuators in push-pull configurations is proposed. Utilizing the fact that the inductances of the solenoids share the same parameters as those for the electromagnetic force, the parameters for the electromagnetic force can be obtained from the easily obtainable electrical signals such as the voltage and current signals, and two inexpensive on-off sensors. The calibration procedure involves only actuating the solenoid actuator back and forth. Simulation study is presented to verify the method.

Fractal Basin Boundaries and Chaotic Motions in Spring-Pendulum System

2003 ◽  
Author(s):  
Aria Alasty ◽  
Rasool Shabani
Keyword(s):  
Numerical Simulations ◽  
Multiple Scales ◽  
Basins Of Attraction ◽  
Chaotic Attractors ◽  
Global Behavior ◽  
Chaotic Motions ◽  
Pendulum System ◽  
Fractal Basin Boundaries ◽  
System Parameters ◽  
Basin Boundaries

This study investigates chaotic response in the spring-pendulum system. In this system beside of strange attractors, multiple regular attractors may coexist for some values of system parameters, where it is important to study the global behavior of the system using the basin boundaries of the attractors. Multiple scales method is used to distinguish the regions of stable and unstable attractors. In unstable regions, bifurcation diagram and poincare´ maps are used to study the existence of quasi-periodic and chaotic attractors. Results show that the jumping phenomena may occur when multiple regular attractors exist and for this case fractal basins of attraction are developed using numerical simulations.

In-space structural assembly using predefined performance based method

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xianliang Zhang ◽  
Weibing Zhu ◽  
Xiande Wu ◽  
Ting Song ◽  
Yaen Xie ◽  
...  
Keyword(s):  
Robust Control ◽  
Collision Avoidance ◽  
Dynamic Models ◽  
Control Method ◽  
Transient State ◽  
Transportation Systems ◽  
Performance Bounds ◽  
Tracking Errors ◽  
Performance Control ◽  
Content Type

Purpose The purpose of this paper is to propose a pre-defined performance robust control method for pre-assembly configuration establishment of in-space assembly missions, and collision avoidance is considered during the configuration establishment process. Design/methodology/approach First, six-degrees-of-freedom error kinematic and dynamic models of relative translational and rotational motion between transportation systems are developed. Second, the prescribed transient-state performance bounds of tracking errors are designed. In addition, based on the backstepping, combining the pre-defined performance control method with a robust control method, a pre-defined performance robust controller is designed. Findings By designing prescribed transient-state performance bounds of tracking errors to guarantee that there is no overshoot, collision-avoidance can be achieved. Combining the pre-defined performance control method with a robust control method, robustness to disturbance is guaranteed. Originality/value This paper proposed a pre-defined performance robust control method. Simulation results demonstrate that the proposed controller can achieve a pre-assembly configuration establishment with collision avoidance in the existence of external disturbances.

scholarly journals Adaptive Sliding Mode Control Method for Z-Axis Vibrating Gyroscope Using Prescribed Performance Approach

2020 ◽  
Vol 10 (14) ◽  
pp. 4779 ◽  
Author(s):  
Cheng Lu ◽  
Liang Hua ◽  
Xinsong Zhang ◽  
Huiming Wang ◽  
Yunxiang Guo
Keyword(s):  
Sliding Mode Control ◽  
Error Bound ◽  
Control Method ◽  
Sliding Mode ◽  
Tracking Error ◽  
Adaptive Sliding Mode Control ◽  
Performance Control ◽  
Prescribed Performance ◽  
Adaptive Sliding Mode ◽  
Mode Control

This paper investigates one kind of high performance control methods for Micro-Electro-Mechanical-System (MEMS) gyroscopes using adaptive sliding mode control (ASMC) scheme with prescribed performance. Prescribed performance control (PPC) method is combined with conventional ASMC method to provide quantitative analysis of gyroscope tracking error performances in terms of specified tracking error bound and specified error convergence rate. The new derived adaptive prescribed performance sliding mode control (APPSMC) can maintain a satisfactory control performance which guarantees system tracking error, at any time, to be within a predefined error bound and the error convergences faster than the error bound. Besides, adaptive control (AC) technique is integrated with PPC to online tune controller parameters, which will converge to their true values at last. The stability of the control system is proved in the Lyapunov stability framework and simulation results on a Z-axis MEMS gyroscope is conducted to validate the effectiveness of the proposed control approach.

scholarly journals Fuzzy-approximation-based prescribed performance control of air-breathing hypersonic vehicles with input constraints

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041987735
Author(s):  
Xingge Li ◽  
Gang Li ◽  
Yan Zhao ◽  
Xuchao Kang
Keyword(s):  
Control Method ◽  
Hypersonic Vehicle ◽  
Hypersonic Vehicles ◽  
Input Constraints ◽  
Air Breathing ◽  
Performance Control ◽  
Prescribed Performance ◽  
Fuzzy Approximation ◽  
Prescribed Performance Control ◽  
Control Scheme

In this article, aiming at the longitudinal dynamics model of air-breathing hypersonic vehicles, a fuzzy-approximation-based prescribed performance control scheme with input constraints is proposed. First, this article presents a novel prescribed performance function, which does not depend on the sign of initial tracking error. And combining prescribed performance control method with backstepping control, the control scheme can ensure that system can converge at a prescribed rate of convergence, overshoot, and steady-state error. In order to solve the problem that backstepping control method needs to be differentiated multiple times, fuzzy approximators are used to estimate the unknown functions, and norm estimation approach is used to simplify the computation of fuzzy approximator. Aiming at the problem of input saturation of actuator in subsystem of air-breathing hypersonic vehicle, the new auxiliary system is designed to ensure the stability and robustness of air-breathing hypersonic vehicle system under input constraints. Finally, the effectiveness of the proposed control strategy is verified by simulation analysis.

scholarly journals Control Strategy and Experiments for Robot Assisted Craniomaxillofacial Surgery System

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Tengfei Cui ◽  
Yonggui Wang ◽  
Xingguang Duan ◽  
Xiaodong Ma
Keyword(s):  
Control Method ◽  
Disease Diagnosis ◽  
Surgical Operation ◽  
Kinematic Parameters ◽  
Robot Assisted ◽  
Robot System ◽  
Positioning Accuracy ◽  
Craniomaxillofacial Surgery ◽  
Surgical Field ◽  
Phantom Experiments

Since the intricate anatomical structure of the craniomaxillofacial region and the limitation of surgical field and instrument, the current surgery is extremely of high risk and difficult to implement. The puncturing operations for biopsy, ablation, and brachytherapy have become vital method for disease diagnosis and treatment. Therefore, a craniomaxillofacial surgery robot system was developed to achieve accurate positioning of the puncture needle and automatic surgical operation. Master-salve control and “kinematic + optics” hybrid automatic motion control based on navigation system, which is proposed in order to improve the needle positioning accuracy, were implemented for different processes of the operation. In addition, the kinematic simulation, kinematic parameters identification, positioning accuracy experiment (0.56 ± 0.21 mm), and phantom experiments (1.42 ± 0.33 mm, 1.62 ± 0.26 mm, and 1.41 ± 0.30 mm for biopsy, radiofrequency, and brachytherapy of phantom experiments) were conducted to verify the feasibility of the hybrid automatic control method and evaluate the function of the surgical robot system.

Sign in / Sign up

Export Citation Format

Share Document