Experiments on Point-to-Point Position Control of a Flexible Beam Using Laplace Transform Technique: Part I—Open-Loop

1991 ◽  
Vol 113 (3) ◽  
pp. 432-437 ◽  
Author(s):  
S. P. Bhat ◽  
M. Tanaka ◽  
D. K. Miu

When lightly damped flexible structures are used in high bandwidth applications, the elimination of residual vibration during point-to-point positioning is an important engineering problem. Using the Laplace domain synthesis technique introduced in earlier publications, experiments on the precise point-to-point position control of a flexible beam have been performed. In Part I of this two-part paper, results related to open-loop control are presented. A variety of candidate control functions are evaluated and performance issues related to robustness and sensitivity are investigated.

1991 ◽  
Vol 113 (3) ◽  
pp. 438-443 ◽  
Author(s):  
S. P. Bhat ◽  
D. K. Miu

Using the Laplace domain synthesis technique documented in earlier publications, experiments on the closed-loop point-to-point position control of a flexible beam are presented. Two different approaches are described, a feed-forward control and an iterative open-loop control. Solution to the robustness problems encountered during actual implementation is also demonstrated.


Author(s):  
J. M. Pottinger ◽  
N. D. Ring

The application of position control to externally powered prosthetic arms leads to increased function and versatility when compared to a prosthetic system with open-loop control. However, various compromises are necessary owing to the limited number of available control sites. An investigation is being conducted into the possibility of combining the advantages of position control during the dynamic phase of movement with the locking facility of velocity–time control during the static phase, which leads to a larger number of available control sites and thus a greater number of degrees of freedom.


2014 ◽  
Vol 602-605 ◽  
pp. 1157-1160
Author(s):  
Mei Yu ◽  
Guo Wei Liu ◽  
Bing Kong

In view of the present mining spraying manipulator operation is not flexible ,spraying effect is poor, susceptible to interference and other issues, this paper studies and realizes a kind of low cost, strong practicability of spraying manipulator control system. Using S7-200PLC and 2MA860H drive to control the 86BYG250A stepper motor open-loop control system, and the precise position control is realized. By controlling of the x-y axis mine spraying manipulator. Validate the system operation is simple, highly efficient and stable, energy conservation and environmental protection, strong anti-jamming capability, it can be widely used in all kinds of mining equipment.


Author(s):  
Q. Tu ◽  
J. Rastegar

Abstract A new approach to trajectory synthesis and formulation of the inverse dynamics model of flexible structures for point to point motions with minimal high frequency component of the actuating torques (forces) is presented. Trajectories are synthesized such that the flexible structure comes to rest undeformed at the completion of motion. The developed method is based on the Trajectory Pattern Method. In this approach, an appropriate trajectory pattern is selected and described in parametric form. The inverse dynamics model of the system is formulated in terms of the trajectory parameters. The trajectory patterns used are in terms of a number of basic sinusoidal time functions and their harmonics. The basic frequencies are selected such that the harmonics appearing in the actuating torques do not excite the natural modes of vibration of the system. For each motion, the trajectory parameters are determined for minimal amplitudes of the higher actuating torque harmonics, noting that from the vibration and control points of view, such trajectories are more desirable. The higher harmonics refers to the harmonics of the actuating torques with frequencies above the highest trajectory harmonic frequency. As an example, a flexible beam undergoing large displacements and rotations in a plane is considered. The effectiveness of the approach is illustrated by an example.


Author(s):  
L. Johan Persson ◽  
Andrew R. Plummer ◽  
Christopher R. Bowen ◽  
Ian Brooks

This paper describes the design, simulation and testing of a piezoelectric spool valve. An actuator has been connected to the valve and tested under closed loop control. A mathematical model of the valve was produced and a prototype of the valve was tested. The mathematical model is validated against the experimental data. Step and frequency responses for both the valve and actuator are presented. It was found that displacement of the hydraulic fluid by the ring bender had an impact on the valve performance. To reduce the effect of the piezoelectric hysteresis, closed loop spool position control was evaluated. A noticeable difference can be observed between open loop and closed loop performance.


2012 ◽  
Vol 468-471 ◽  
pp. 1448-1452 ◽  
Author(s):  
Jian Chen ◽  
Jian Ping Shu ◽  
Mian Li ◽  
Qi Zhou ◽  
Zhu Ming Su

The flow rate of a novel self-spinning high speed hydraulic on/off valve is regulated by changing the relative axial position (the duty cycle) of the valve spool to the nozzles located on the valve body through driving a gerotor pump using brushless direct current motor. The closed loop axial position control system of the valve spool with feedback of the axial displacement of the valve spool has shorter response time, and not more ripple of output pressure than corresponding open loop control system. A fuzzy logic parameter self-tuning PID controller is investigated to overcome nonlinearity of the control system. The simulation results show that the overshoot is decreased greatly than conventional PID controller.


Author(s):  
S B Choi ◽  
J K Yoo

This paper presents a robust pressure control of a pneumatic valve system driven by piezoceramic actuators. The piezoceramic actuator bonded to both sides of a flexible beam makes a movement required to control the pressure at the flapper nozzle of a pneumatic system. After deriving the governing equation of motion, an appropriate size of the valve system is constructed. A sliding mode controller that is known to be robust to system uncertainties is then formulated in order to achieve accurate tracking control of a set of desired pressure trajectories. The closed-loop control bandwidth of the proposed valve system is empirically evaluated with respect to the supplying pressure and desired pressure. Tracking control performances for various pressure trajectories are presented in the time domain. In addition, the pressure control response achieved from the proposed feedback control method is compared with the response obtained from the open-loop control method.


Author(s):  
Ammar N. Abbas ◽  
Muhammad Asad Irshad

Robotic arms are considered as a cantilever beam fixed at one end and due to the length-to-weight ratio, it has a significant vibration-induced that needs to be controlled to achieve accurate position, speed control and to increase its efficiency. In this project, a discretized Timoshenko beam model is used to discuss the dynamics of the system. Further, to implement the control on the hardware an experimental setup is fabricated to observe the open-loop and closed-loop responses of the beam made of low-density polyethylene. An accelerometer as a feedback sensor is attached at one end of the flexible beam while another end is fixed at the moving cart having DC motor as an actuator. Simulink is used as the programming tool to perform all of the experimentation. Proportional-integral-derivative (PID) tuning is performed. Following that open-loop responses of the deflection of the beam parallel to the motion are observed with different input waveforms. By applying a proportional control scheme, another experiment is performed to demonstrate the disturbance rejection with an accelerometer as a feedback sensor, while ignoring position control. Finally, a PD and P based parallel control scheme is proposed to obtain simultaneously both position control and vibration reduction.


2016 ◽  
Vol 28 (5) ◽  
pp. 646-653 ◽  
Author(s):  
Akira Abe ◽  
◽  
Keisuke Okabe ◽  

[abstFig src='/00280005/05.jpg' width='250' text='Photograph of the experimental setup' ] We present a simple antisway control method for a rotary crane, whose load can move in a two-dimensional plane. In particular, we investigate the suppression of residual sway motion of a rotary crane with a boom that performs point-to-point motion. In the proposed method, we attempt to generate the trajectory of the boom using a combination of polynomial and cycloidal functions. The profile of the generated trajectory depends on the coefficients of the polynomial function. Thus, it is necessary to tune the coefficients to minimize the sway motion in the two-dimensional plane as much as possible. We adopt a particle swarm optimization algorithm, an evolutionary computation technique, to tune the coefficients and then obtain the optimal trajectory. By rotating the boom along the optimal trajectory, the two-dimensional residual sway motion is suppressed, i.e., an open-loop control is realized. The effectiveness and feasibility of the proposed control scheme is demonstrated via simulations and experiments.


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