Considerations on a Mass-Based System Representation of a Pneumatic Cylinder

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
M. Brian Thomas ◽  
Gary P. Maul
Keyword(s):  
Total Mass ◽  
Control Valve ◽  
System Model ◽  
Order System ◽  
Pneumatic Cylinder ◽  
State Variables ◽  
Pneumatic Actuators ◽  
Reduced Order ◽  
Highly Nonlinear ◽  
And Control

Pneumatic actuators can be advantageous over electromagnetic and hydraulic actuators in many servo motion applications. The difficulty in their practical use comes from the highly nonlinear dynamics of the actuator and control valve. Previous works have used the cylinder’s position, velocity, and internal pressure as state variables in system models. This paper replaces pressure in the state model with the mass of gas in each chamber of the cylinder, giving a better representation of the system dynamics. Under certain circumstances, the total mass of gas in the cylinder may be assumed to be constant. This allows development of a reduced-order system model.

Brake System Modeling for Simulation and Control

1999 ◽  
Vol 121 (3) ◽  
pp. 496-503 ◽  
Author(s):  
J. Christian Gerdes ◽  
J. Karl Hedrick
Keyword(s):  
System Modeling ◽  
Control Valve ◽  
Brake System ◽  
Reduced Order ◽  
Pedal Force ◽  
Modeling Process ◽  
Brake Pressure ◽  
Simplifying Assumptions ◽  
Rapid Transients ◽  
And Control

This paper presents reduced-order models of brake system dynamics derived from a physical modeling perspective. The vacuum booster model combines a static control valve with dynamic air flows, resulting in the ability to easily reproduce both static hysteresis effects and rapid transients. Following the assumption of incompressible flow, a four-state model of the brake hydraulics is presented and, subsequently, reduced to one or two states for certain applications. Experimental results support the simplifying assumptions made during the modeling process by demonstrating better agreement with the response from pedal force to brake pressure than previously displayed in the literature. These models are intended for use in the design and analysis of vehicle control systems and the evaluation of driver/vehicle interactions through dynamic simulation.

Study on Fault Simulation for Pneumatic Actuator Model

2013 ◽  
Vol 706-708 ◽  
pp. 1025-1028 ◽  
Author(s):  
Zhi Gang Feng ◽  
Xue Juan Zhang
Keyword(s):  
System Modeling ◽  
Fault Simulation ◽  
Control Valve ◽  
Pneumatic Actuator ◽  
Actuator Failure ◽  
Matlab Simulink ◽  
Pneumatic Actuators ◽  
Actuator System ◽  
Working Principle ◽  
And Control

Actuator, as the execution of the terminal unit of the control system is directly related to the safe and reliable operation of the production process, and once actuators in the system malfunction, will bring huge losses. The research on pneumatic actuator not only devote to the study of its structure, but also need to study the basic theory of the actuator system modeling, and Laid a foundation for the study of the actuator fault diagnosis. Firstly, this paper introduces the components and working principle of the pneumatic actuators which mainly include three parts: pneumatic servomotor, positioner, and control valve. Secondly, the DABlib modules of MATLAB/Simulink as the simulation model of actuator failure are introduced. Finally, we analyzed the common faults of the pneumatic servomotor, positioner, and control valve, and in the MATLAB/Simulink environment, the faults are simulated, and describes the phenomenon of two typical fault.

Development of Wearable Pneumatic Actuator and Multiport Pressure Control Valve

2005 ◽  
Vol 17 (5) ◽  
pp. 529-536 ◽  
Author(s):  
Tetsuya Akagi ◽  
◽  
Shujiro Dohta
Keyword(s):  
Degrees Of Freedom ◽  
Force Feedback ◽  
Control Valve ◽  
Pressure Control ◽  
Pneumatic Actuator ◽  
Pneumatic Cylinder ◽  
Pneumatic Actuators ◽  
Care Systems ◽  
Active Research ◽  
Pressure Control Valve

Recently, force feedback devices in virtual reality and power assisted nursing care systems have received much attention and active research. Some involve an actuator and a driving device, such as a pneumatic cylinder and a control valve, worn by the user. Such devices must be compact, lightweight and flexible to avoid excessive load on and injury to the user. The purpose of our study is to develop a flexible and lightweight actuator which can be safe enough to be attached to the human body. We proposed new flexible pneumatic actuators that operate even if the actuator is deformed by external force. We tested a push-pull and flexible pneumatic actuator that moves straight and rotates. We proposed and developed a multiport pressure control valve that drives multiple wearable actuators while reducing the weight of the control valve for multiple degrees of freedom of motion.

scholarly journals Modeling and Control of a New Robotic Deburring System

2007 ◽  
Vol 129 (5) ◽  
pp. 965-972 ◽  
Author(s):  
Changhoon Kim ◽  
Jae H. Chung
Keyword(s):  
Feedback Linearization ◽  
Control Method ◽  
Pneumatic Cylinder ◽  
Coordination Control ◽  
External Disturbances ◽  
Pneumatic Actuators ◽  
Modeling And Control ◽  
Control Approach ◽  
And Control ◽  
Speed Simulation

This paper discusses the modeling and control of a robotic manipulator with a new deburring tool, which integrates two pneumatic actuators to take advantage of a double cutting action. A coordination control method was developed by decomposing the robotic deburring system into two subsystems: the arm and the deburring tool. A decentralized control approach was pursued in which suitable controllers were designed for the two subsystems in the coordination scheme. Robust feedback linearization was utilized to minimize the undesirable effect of external disturbances, such as static and Coulomb friction and nonlinear compliance of the pneumatic cylinder stemming from the compressibility of air. The developed coordination control method demonstrated its efficacy in terms of deburring accuracy and speed. Simulation results show that the developed robotic deburring system significantly improves the accuracy of the deburring operation.

scholarly journals Sensor-Less and Control-Less Underactuated Grippers With Pull-In Mechanisms for Grasping Various Objects

2021 ◽  
Vol 8 ◽  
Author(s):  
Atsushi Kakogawa ◽  
Yuki Kaizu ◽  
Shugen Ma
Keyword(s):  
Design Methodology ◽  
Control Valve ◽  
Planetary Gear ◽  
Dc Motor ◽  
Reduction Gear ◽  
Relief Valve ◽  
Pneumatic Actuators ◽  
Different Types ◽  
High Reduction ◽  
And Control

This paper proposes an underactuated grippers mechanism that grasps and pulls in different types of objects. These two movements are generated by only a single actuator while two independent actuators are used in conventional grippers. To demonstrate this principle, we have developed two kinds of gripper by different driving systems: one is driven by a DC motor with planetary gear reducers and another is driven by pneumatic actuators with branch tubes as a differential. Each pulling-in mechanism in the former one and the latter one is achieved by a belt-driven finger surface and a linear slider with an air cylinder, respectively. The motor-driven gripper with planetary gear reducers can pull-up the object after grasping. However, the object tends to fall when placing because it opens the finger before pushing out the object during the reversed movement. In addition, the closing speed and the picking-up speed of the fingers are slow due to the high reduction gear. To solve these drawbacks, a new pneumatic gripper by combining three valves, a speed control valve, a relief valve, and non-return valves, is proposed. The proposed pneumatic gripper is superior in the sense that it can perform pulling-up after grasping the object and opening the fingers after pushing-out the object. In the present paper, a design methodology of the different underactuated grippers that can not only grasp but also pull up objects is discussed. Then, to examine the performance of the grippers, experiments were conducted using various objects with different rigidity, shapes, size, and mass, which may be potentially available in real applications.

scholarly journals Parameters Estimation and Prediction of Water Movement and Solute Transport in Layered, Variably Saturated Soils Using the Ensemble Kalman Filter

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1520
Author(s):  
Zheng Jiang ◽  
Quanzhong Huang ◽  
Gendong Li ◽  
Guangyong Li
Keyword(s):  
Kalman Filter ◽  
Solute Transport ◽  
Ensemble Kalman Filter ◽  
Water Movement ◽  
Parameters Estimation ◽  
Saturated Soils ◽  
Hydrological Models ◽  
State Variables ◽  
Ensemble Size ◽  
Highly Nonlinear

The parameters of water movement and solute transport models are essential for the accurate simulation of soil moisture and salinity, particularly for layered soils in field conditions. Parameter estimation can be achieved using the inverse modeling method. However, this type of method cannot fully consider the uncertainties of measurements, boundary conditions, and parameters, resulting in inaccurate estimations of parameters and predictions of state variables. The ensemble Kalman filter (EnKF) is well-suited to data assimilation and parameter prediction in Situations with large numbers of variables and uncertainties. Thus, in this study, the EnKF was used to estimate the parameters of water movement and solute transport in layered, variably saturated soils. Our results indicate that when used in conjunction with the HYDRUS-1D software (University of California Riverside, California, CA, USA) the EnKF effectively estimates parameters and predicts state variables for layered, variably saturated soils. The assimilation of factors such as the initial perturbation and ensemble size significantly affected in the simulated results. A proposed ensemble size range of 50–100 was used when applying the EnKF to the highly nonlinear hydrological models of the present study. Although the simulation results for moisture did not exhibit substantial improvement with the assimilation, the simulation of the salinity was significantly improved through the assimilation of the salinity and relative solutetransport parameters. Reducing the uncertainties in measured data can improve the goodness-of-fit in the application of the EnKF method. Sparse field condition observation data also benefited from the accurate measurement of state variables in the case of EnKF assimilation. However, the application of the EnKF algorithm for layered, variably saturated soils with hydrological models requires further study, because it is a challenging and highly nonlinear problem.

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