Dynamic Analysis and Simulation of a 1-DOF Driven by a Parallel Force/Velocity Actuator (PFVA)

2007 ◽  
Author(s):  
Dinesh Rabindran ◽  
Delbert Tesar
Keyword(s):  
Numerical Simulation ◽  
Dynamic Model ◽  
Force Control ◽  
Gear Train ◽  
Control Mode ◽  
Velocity Control ◽  
Dynamic Coupling ◽  
Force And Motion ◽  
Prime Movers ◽  
Force Velocity

Some work has been done to try to combine force control and velocity control capability into the same actuator design. The objective in trying to incorporate two fundamentally distinct resources (force and motion priorities) into the same actuator is to obtain an expanded spectrum of dynamic responses at the output of the system so that the system may (ideally) operate in pure force control mode or pure velocity control mode or a combination of these modes. Presented in this paper is a design that combines two fundamentally distinct actuators (one using low reduction or even direct drive, which we will call a Force Actuator (FA) and the other with a high reduction gear train that we will refer to as a Velocity Actuator (VA)). The premise of this work is that we could obtain a variety of responses at the system’s output by integrating separate force and motion priorities (Parallel Force/Velocity Actuator) within the same system in-parallel and dynamically “mixing” their contributions. We conceptually describe a Parallel Force/Velocity Actuator (PFVA) based on a Dual-Input-Single-Output (DISO) epicyclic gear train. We then present a dynamic model formulation for a non-linear 1-DOF mechanical system (Slider-Crank Mechanism) that uses a PFVA at the input. Using this dynamic model, we present a numerical simulation. The numerical simulation focuses on two issues, (a) effect of the relative scale change (ρ) between the two inputs on the torques at the two prime-movers and (b) effect of ρ on the dynamic coupling between the inputs. It was observed that as the relative scale change (represented by ρ) was decreased (i.e. the sub-systems tend towards behaving as “equal” systems) the dynamic coupling between the systems increased. In the study of the effect of ρ on the inertia and static torques at the prime-movers, it was noticed that they follow inverse trends.

Modeling and Pressure-Based Force Control of a Hydraulic Actuator

1997 ◽  
Author(s):  
Scott M. Lyon ◽  
Mark S. Evans
Keyword(s):  
Dynamic Model ◽  
Force Control ◽  
Feedback Linearization ◽  
External Surface ◽  
Bond Graph ◽  
Hydraulic Pressure ◽  
Velocity Control ◽  
Hydraulic Actuator ◽  
Spool Valve ◽  
Piston Position

Abstract A dynamic model of a hydraulic actuator/spool valve combination is developed using the bond graph method. Feedback linearization is used to develop a force controller for the system using hydraulic pressure in each chamber of the actuator along with piston position and velocity as feedback. The use of a feedforward term to compensate for the seal friction within the actuator provides for a stable and accurate controller. Velocity control is achieved through calculation of the reference force required to overcome the seal friction and produce the acceleration required to reach the desired velocity. It is shown that the use of such a force controller allows for an acceptable transition from velocity to force control when the piston comes in contact with an external surface.

Automatic Swing Door for a Passenger Car by Using Parallel Force/Velocity Actuator (PFVA)

2013 ◽  
Vol 278-280 ◽  
pp. 641-646 ◽  
Author(s):  
Min Kyu Park ◽  
Dinesh Rabindran ◽  
Delbert Tesar ◽  
Byoungsoo Lee ◽  
Kum Gil Sung
Keyword(s):  
Gear Train ◽  
Reduction Gear ◽  
Velocity Control ◽  
Simulation Environment ◽  
Passenger Car ◽  
Reference Velocity ◽  
Single Output ◽  
Force Velocity ◽  
Feasibility Test ◽  
Force Compensation

A vehicle's door is frequently used by a driver or passengers. When a vehicle is parked at incline, it is not easy to open or close doors because of gravity force and external disturbances. Moreover, there might cause a safety problems for a weak or a disabled person. Therefore, there is increasing demand for automation of vehicle's door. In this study, an automatic swing door mechanism for a passenger car is proposed by using a parallel force/velocity actuator (PFVA) based on a Dual-Input-Single-Output (DISO) framework. PFVA has two distinct actuators. One is force actuator(FA) with a low reduction gear train, the other is velocity actuator(VA) with a high reduction gear train. It can be effectively used in combining velocity control with force compensation application. First, we formulated a kinematics and a dynamics of automatic swing door system with PFVA as input, and then a simulation environment was developed for a feasibility test by using a kinematic and a dynamic model. Finally, a velocity control with force compensation was performed by using the developed simulation environment. VA was faithfully followed a reference velocity trajectory for opening and closing a door, and FA was able to compensate a gravity torque and an inertial disturbance torque coming from the VA.

Force-Position Hybrid Control of a New Parallel Hexapod Robot for Drilling Holes on Fuselage Surface

2013 ◽  
Author(s):  
Xianchao Zhao ◽  
Yang Pan ◽  
Feng Gao
Keyword(s):  
Dynamic Model ◽  
Force Control ◽  
Parallel Mechanism ◽  
Control Method ◽  
Hybrid Control ◽  
Control Mode ◽  
Work Status ◽  
Legged Robot ◽  
Hexapod Robot ◽  
Robot Performance

In this paper, a new kind of 6-legged robot for drilling holes on the aircraft surface is presented. Each leg of the robot is a parallel mechanism with 3 degree of freedoms thus the robot includes totally 18 motors. Due to different work status, the control modes of these motors are also different and thus the force-position hybrid control method is applied. The kinematic and dynamic model is briefly introduced. Then the robot gait is discussed. After that hybrid control method is introduced: first the control mode of each motor should be determined, then the position or force control curves should be calculated. In the end of this paper, both virtual and real prototype of this robot is showed and the experiment result showed that the hybrid control method can significantly improve the robot performance.

Numerical simulation of magnus force control for projectiles configurations

2009 ◽  
Vol 38 (4) ◽  
pp. 965-968 ◽  
Author(s):  
Franck Simon ◽  
Sébastien Deck ◽  
Philippe Guillen ◽  
Alain Merlen ◽  
Roxan Cayzac
Keyword(s):  
Numerical Simulation ◽  
Force Control ◽  
Magnus Force

Dynamics of the Gear Train Set in Wind Turbine

2011 ◽  
Vol 697-698 ◽  
pp. 701-705
Author(s):  
D.D. Ji ◽  
Y.M. Song ◽  
J. Zhang
Keyword(s):  
Wind Turbine ◽  
Dynamic Model ◽  
Harmonic Balance Method ◽  
Planetary Gear ◽  
Gear Train ◽  
Dynamic Responses ◽  
Multi Stage ◽  
Lumped Parameter ◽  
Cartesian Coordinate ◽  
The Impact

A lumped-parameter dynamic model for gear train set in wind turbine is proposed to investigate the dynamics of the speed-increasing gear box. The proposed model is developed in a universal Cartesian coordinate, which includes transversal and torsional deflections of each component, time-varying mesh stiffness, gear profile errors and external excitations. By solving the dynamic model, a modal analysis is performed. The results indicate that the modal properties of the multi-stage gear train in wind turbine are similar to those of a single-stage planetary gear set. A harmonic balance method (HBM) is used to obtain the dynamic responses of the gearing system. The responses give insight into the impact of excitations on the vibrations.

Force/Velocity Control of a Pneumatic Gantry Robot for Contour Tracking With Neural Network Compensation

2008 ◽  
Author(s):  
Mohammed Abu-Mallouh ◽  
Brian Surgenor
Keyword(s):  
Neural Network ◽  
Coulomb Friction ◽  
Tangential Velocity ◽  
Limiting Factor ◽  
Contour Tracking ◽  
Velocity Control ◽  
Hybrid Controller ◽  
Controller Performance ◽  
Force Velocity ◽  
Gantry Robot

In this paper, the application of a pneumatic gantry robot to contour tracking is examined. A hybrid controller is structured to control the contact force and the tangential velocity, simultaneously. A previous study provided controller tuning and model validation results for a fixed gain PI-based force/velocity controller. Performance was limited by system lag and Coulomb friction. New results demonstrate that even with perfect friction compensation, the limiting factor is the system lag. A neural network (NN) compensator was subsequently developed to counter both effects. Results for straight and curved edged workpieces are presented to demonstrate the effectiveness of the NN compensator and the capabilities of a pneumatic gantry robot.

Reliable Analysis on Fast Valving of Ultra-Supercritical Unit Under Transient Fault Conditions

2017 ◽  
Author(s):  
Yu Cai ◽  
Wei Li ◽  
Bao Zhang ◽  
Wenjian Wu ◽  
Deren Sheng ◽  
...  
Keyword(s):  
Power System ◽  
Steam Turbine ◽  
Dynamic Model ◽  
Transient Stability ◽  
Power Grid ◽  
Load Shedding ◽  
Control Mode ◽  
Normal Operation ◽  
Transient Fault ◽  
The Stability

Fast valving of ultra-supercritical unit has great effects on over-speed prevention, load-shedding control, transient stability analysis of electrical system and other security problems. The purpose of fast valving is to maintain the stability of power system once fault or load shedding of unit occurs in the electric power system. Therefore, it is of great significance to study the reliability of fast valving for ultra-supercritical unit. In this paper, the KU ( short shedding) logic condition of SIEMENS T3000 system is analyzed as the research object of fast valving. The unit can be avoided over speed by monitoring the unit load and fast valving under faulty grid conditions based on the KU control. A series of measures will be taken after KU is triggered, for instance the governing valving will be closed quickly and the DEH (digital electro-hydraulic) control of the steam turbine will be switched to speeding control mode. On the other hand, the unit will return to normal operation if the transient fault of power grid disappears. The key contributions of this thesis include three parts: Firstly, based on the analysis of control characteristics of ultra-supercritical unit and protective logic and triggered conditions of KU function, a novel dynamic model by coupling the fast valving of steam turbine and the transient stability of generator is established by applying the PSCAD software. Then, the dynamic response process of ultra-supercritical unit is simulated and calculated by adopting the coupling dynamic model when KU function is triggered. Also the influence factors and reliability of fast valving are analyzed under transient fault conditions. Finally, two optimized measures by increasing the time delay and the speed of quantitative judgment are put forward to reduce risks and avoid the misoperation of signal distortion which may be caused by the power transmitter under transient fault conditions. The results of this study can not only help to evaluate the reliability of fast valving function scientifically in power grid transient fault, but also guide the technicians to analyze the stability of the power grid.

scholarly journals Hydrodynamic Analysis of Self-Propulsion Performance of Wave-Driven Catamaran

2021 ◽  
Vol 9 (11) ◽  
pp. 1221
Author(s):  
Weixin Zhang ◽  
Ye Li ◽  
Yulei Liao ◽  
Qi Jia ◽  
Kaiwen Pan
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Dynamic Model ◽  
Dynamic Structure ◽  
Ocean Waves ◽  
Static State ◽  
Small Surface ◽  
Propulsion Performance ◽  
Multi Body ◽  
Body Dynamic

The wave-driven catamaran is a small surface vehicle driven by ocean waves. It consists of a hull and hydrofoils, and has a multi-body dynamic structure. The process of moving from static state to autonomous navigation driven by ocean waves is called “self-propulsion”, and reflects the ability of the wave-driven catamaran to absorb oceanic wave energy. Considering the importance of the design of the wave-driven catamaran, its self-propulsion performance should be comprehensively analysed. However, the wave-driven catamaran’s multi-body dynamic structure, unpredictable dynamic and kinematic responses driven by waves make it difficult to analyse its self-propulsion performance. In this paper, firstly, a multi-body dynamic model is established for wave-driven catamaran. Secondly, a two-phase numerical flow field containing water and air is established. Thirdly, a numerical simulation method for the self-propulsion process of the wave-driven catamaran is proposed by combining the multi-body dynamic model with a numerical flow field. Through numerical simulation, the hydrodynamic response, including the thrust of the hydrofoils, the resistance of the hull and the sailing velocity of the wave-driven catamaran are identified and comprehensively analysed. Lastly, the accuracy of the numerical simulation results is verified through a self-propulsion test in a towing tank. In contrast with previous research, this method combines multi-body dynamics with computational fluid dynamics (CFD) to avoid errors caused by artificially setting the motion mode of the catamaran, and calculates the real velocity of the catamaran.

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