scholarly journals A control solution for closed-form mechanisms of relative manipulation based on fuzzy approach

2019 ◽  
Vol 16 (2) ◽  
pp. 172988141983981 ◽  
Author(s):  
Nguyen Van Toan ◽  
Phan Bui Khoi
Keyword(s):  
Closed Form ◽  
Fuzzy Controller ◽  
Control Algorithms ◽  
Dynamical Equations ◽  
Kinematic Relationship ◽  
Noisy Signals ◽  
Mathematical Equations ◽  
Relationship Of ◽  
Manipulation Robot ◽  
Computed Torque

Closed-form mechanisms of relative manipulation robot is an effective structure which helps to improve the accuracy and flexibility in technological processes. Unfortunately, the requirement about knowledge of exact dynamics of closed-form mechanisms of relative manipulation robot is arduous since it consists of numerous joints and links, and the identification of the kinematic relationship of closed-form structure is also complicated. This causes several shortcomings for controlling closed-form mechanisms of relative manipulation robot by using vector control algorithms because these methods require exactly dynamical equations of control systems. In contrast, the fuzzy controllers do not require knowledge of detailed mathematical equations of the control system since the fuzzy sets aim to capture the semantics of natural linguistic terms present in the fuzzy controller knowledge. Moreover, they have capability of handling uncertain and noisy signals, this helps to deal with the external environmental forces. This article proposes a fuzzy-based controller for closed-form mechanisms of relative manipulation robot to overcome mentioned problems by eliminating the identification of exact dynamics and kinematic constraints of closed-form structure. To verify the performance of the proposed method, the fuzzy-based controller is applied to a welding task by using a model of two-component mechanism which includes one closed-form manipulator and one serial manipulator. The welding task is also conducted by using conventional controllers in which the detailed dynamical equation is applied for the proportional–derivative (PD)-type and proportional integral derivative (PID)-type computed torque controllers, whereas the fuzzy-based controller just uses several nominal parameters.

scholarly journals APPLICATION OF HEDGE ALGEBRAS FOR CONTROLLING MECHANISMS OF RELATIVE MANIPULATION

2017 ◽  
Vol 55 (5) ◽  
pp. 572
Author(s):  
Phan Bui Khoi ◽  
Nguyen Van Toan
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Controller ◽  
Complex Structure ◽  
Algebraic Approach ◽  
Linguistic Variables ◽  
Fuzzy Relations ◽  
Dynamical Equations ◽  
Linguistic Hedges ◽  
Linguistic Labels ◽  
Computed Torque

This paper presents a method for controlling mechanism of relative manipulation (MRM robot), that based on an algebraic approach to linguistic hedges in fuzzy logic. The proposed model of MRM robot is introduced as two component mechanisms, collaborating to realize technological manipulations. MRM robot has complex structure [1, [2]; therefore, robot system's  mathematical equations describing dynamical behaviors are complicated and voluminous [3,[4, 5]. Furthermore, the components affect MRM robot's dynamics that are difficult to determine adequately and exactly. Applying the well-known methods (based on dynamical equations) such as PD/PID, computed torque algorithm...for robot control is difficult, especially with MRM robot. By dint of the human-like inference mechanism, designing controller thanks to fuzzy logic can overcome the mentioned drawbacks [6]. However, the linguistic variables in fuzzy logic are not represented by any physical values; and hence, the comparison between the linguistic variables is unable. Moreover, composition of fuzzy relations, defuzzification use approximation function which can trigger error in data process. Hedge Algebras(HA) gives favorable conditions to restrict fuzzy logic's drawbacks because the linguistic labels in Hedge Algebras are represented by semantic values; and, composition of fuzzy relations and defuzzification are processed by simple interpolation and mapping functions. The obtained results from HA controller are compared to the obtained results from two methods which are presented in [6] (fuzzy controller and computed torque controller). Keywords: mechanism of relative manipulation (MRM robot), hedge algebras.

Comparative studies of the set up of two-dimensional pneumatic arm systems by muscle and rotational actuators

2007 ◽  
Vol 221 (5) ◽  
pp. 743-748 ◽  
Author(s):  
Y-T Wang ◽  
R-H Wong ◽  
J-T Lu
Keyword(s):  
Control Systems ◽  
Fuzzy Controller ◽  
Control Algorithms ◽  
Two Dimensional ◽  
Pneumatic Control ◽  
Learning Mechanism ◽  
Set Up ◽  
And Control ◽  
Self Learning ◽  
System Characteristics

As opposed to traditional pneumatic linear actuators, muscle and rotational actuators are newly developed actuators in rotational and specified applications. In the current paper, these actuators are used to set up two-dimensional pneumatic arms, which are used mainly to simulate the excavator's motion. Fuzzy control algorithms are typically applied in pneumatic control systems owing to their non-linearities and ill-defined mathematical model. The self-organizing fuzzy controller, which includes a self-learning mechanism to modify fuzzy rules, is applied in these two-dimensional pneumatic arm control systems. Via a variety of trajectory tracking experiments, the present paper provides comparisons of system characteristics and control performances.

Design of the Conjugate Cam Induction Hardening Mechanism and Establishment of the Motion Controlling Mathematical Model

2012 ◽  
Vol 155-156 ◽  
pp. 726-730
Author(s):  
Zhong Hua Li ◽  
Qian Tang ◽  
Di Yan ◽  
Jie Wu
Keyword(s):  
Mathematical Model ◽  
Induction Hardening ◽  
Uniform Motion ◽  
Hardening Mechanism ◽  
Kinematic Relationship ◽  
Nc Machine ◽  
The Common ◽  
Relationship Of ◽  
The Mathematical Model ◽  
Basic Motion

The common methods of cam induction hardening are discussed at present. By analyzing the basic motion law of conjugate cam, a new induction hardening mechanism is designed. The motion controlling mathematical model is built on the basis of the kinematic relationship of the transmission of the induction hardening mechanism. Through the mathematical model calculation, we can get angular velocity of the workbench, then realize that single axis on NC machine controls the inductor to make isometric uniform motion relative to the cam surface, so that the cam hardening depth distribution is uniform.

scholarly journals Decomposition of M/M/1 With Unreliable Service and a Working Vacation

2020 ◽  
Vol 9 (1) ◽  
pp. 63
Author(s):  
Joshua Patterson ◽  
Andrzej Korzeniowski
Keyword(s):  
Closed Form ◽  
Failure Rate ◽  
Waiting Time ◽  
Queue Length ◽  
Service Failure ◽  
Working Vacation ◽  
Stationary Queue Length ◽  
Stationary Waiting Time ◽  
Relationship Of ◽  
The Relationship

We use the stationary distribution for the M/M/1 with Unreliable Service and aWorking Vacation (M/M/1/US/WV) given explicitly in (Patterson & Korzeniowski, 2019) to find a decomposition of the stationary queue length N. By applying the distributional form of Little's Law the Laplace-tieltjes Transform of the stationary customer waiting time W is derived. The closed form of the expected value and variance for both N and W is found and the relationship of the expected stationary waiting time as a function of the service failure rate is determined.

Automatic Parking Control Algorithms and Simulation Research Based on Fuzzy Controller

2020 ◽  
Author(s):  
Agyeman Kwabena Philip ◽  
Micheal Sackey ◽  
Prince Owusu-Ansah ◽  
Mohamed A. Hassan ◽  
Jamshid F. Valiev ◽  
...  
Keyword(s):  
Fuzzy Controller ◽  
Control Algorithms ◽  
Simulation Research ◽  
Automatic Parking

Robust Computed Torque Schemes for Mechanical Manipulators: Nonadaptive Versus Adaptive

1991 ◽  
Vol 113 (2) ◽  
pp. 324-327 ◽  
Author(s):  
Y. H. Chen
Keyword(s):  
Finite Time ◽  
Tracking Control ◽  
Tracking Error ◽  
Statistical Information ◽  
Torque Control ◽  
Control Algorithms ◽  
Computed Torque Control ◽  
Control Schemes ◽  
Mechanical Manipulators ◽  
Computed Torque

We consider the tracking control problem of mechanical manipulators in the presence of uncertainty. Two classes of control algorithms are proposed. If the possible bound of the uncertainty is known, a class of nonadaptive robust computed torque control schemes is used. The control guarantees the tracking error to be confined within a specified region after a finite time. If the bound of uncertainty is unknown, a class of adaptive robust computed torque control schemes is used. The control guarantees the tracking error to converge to zero. Both classes of controls are continuous. No statistical information on the uncertainty is ever assumed.

The Kinematic Design of 2K-2H Planetary Gear Reducers with High Reduction Ratio

2013 ◽  
Vol 319 ◽  
pp. 610-615 ◽  
Author(s):  
Long Chang Hsieh ◽  
Hsiu Chen Tang
Keyword(s):  
Planetary Gear ◽  
Reduction Ratio ◽  
Gear Train ◽  
Design Algorithm ◽  
Kinematic Design ◽  
Planetary Gear Trains ◽  
Kinematic Relationship ◽  
Gear Trains ◽  
High Reduction ◽  
Relationship Of

The power system equipped in machinery contains power source (motor or engine) and gear reducer to get large output torque. The rotation speed of motor is made higher and higher to obtain high power with the same volume. Hence, the reduction ratio of gear reducer is required to be higher and higher. Planetary gear trains can be used as the gear reducers with high reduction ratio. However, the planetary gear train with high reduction ratio is compound gear system. The purpose of this paper is to propose 2K-2H type planetary gear reducers with high reduction ratio. Based on the concept of train value equation, we propose a new representation to present the kinematic relationship of the members of the train circuit. According to this representation graph, we propose an algorithm for the kinematic design of planetary simple gear trains with high reduction ratio. Some 2K-2H type planetary gear reducers are designed to illustrate the design algorithm.

HEAT KERNEL MODELS FOR ASSET PRICING

2014 ◽  
Vol 17 (07) ◽  
pp. 1450048 ◽  
Author(s):  
ANDREA MACRINA
Keyword(s):  
Asset Pricing ◽  
Closed Form ◽  
Heat Kernel ◽  
Term Structure ◽  
Risk Premium ◽  
Jump Processes ◽  
Dynamical Equations ◽  
Pricing Kernel ◽  
Kernel Approach ◽  
The Impact

A heat kernel approach is proposed for the development of a novel method for asset pricing over a finite time horizon. We work in an incomplete market setting and assume the existence of a pricing kernel that determines the prices of financial instruments. The pricing kernel is modeled by a weighted heat kernel driven by a multivariate Markov process. The heat kernel is chosen so as to provide enough freedom to ensure that the resulting model can be calibrated to appropriate data, e.g. to the initial term structure of bond prices. A class of models is presented for which the prices of bonds, caplets, and swaptions can be computed in closed form. The dynamical equations for the price processes are derived, and explicit formulae are obtained for the short rate of interest, the risk premium, and for the stochastic volatility of prices. Several of the closed-form models presented are driven by combinations of Markovian jump processes with different probability laws. Such models provide a basis for consistent applications in various market sectors, including equity markets, fixed-income markets, commodity markets, and insurance. The flexible multidimensional and multivariate structure on which the resulting price models are based lends itself well to the modeling of dependence across asset classes. As an illustration, the impact of spiraling debt, a typical feature of a financial crisis, is modeled explicitly, and the contagion effects can be readily observed in the dynamics of the associated asset returns.

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