Modeling and Adaptive Robust Posture Control of 3-RPS Pneumatic Parallel Platform

2015 ◽  
Author(s):  
Ce Shang ◽  
Guoliang Tao ◽  
He Zuo ◽  
Deyuan Meng
Keyword(s):  
Physical System ◽  
Position Control ◽  
Controller Design ◽  
Parameters Estimation ◽  
Posture Control ◽  
Pneumatic Cylinder ◽  
Nonlinear Characteristic ◽  
Parameters Uncertainty ◽  
Proportional Value ◽  
Parallel Platform

Due to the compressibility, nonlinear characteristic and parameters uncertainty, the position control of a pneumatic cylinder or parallel platform is still very difficult while compared with the electro-driven ones. In this paper, the dynamic model of a single proportional value controlled pneumatic cylinder is established. In order to reduce the affection of the parameters uncertainty, the online parameters estimation is adopted into the controller design. Based on the NI CompactRio hardware and Veristand platform, the algorithm is realized to the physical system successfully. The position error is generally lower than 1%. Then, the algorithm is expanded to the problem for the 3-RPS pneumatic parallel platform. The Lyapunov’s method is used to prove the effectiveness of controller and the experiment results show that the posture error of the platform can be as low as 0.5%. By using this approach, the pneumatic ones can be much more competitive and valuable in the industrial market of position or posture control.

Automated System of Stabilization and Position Control of Aviation Equipment

2019 ◽  
pp. 297-330
Author(s):  
Olha Sushchenko
Keyword(s):  
Position Control ◽  
Transfer Functions ◽  
Controller Design ◽  
Robust Stabilization ◽  
Automated System ◽  
Simulink Model ◽  
The Matrix ◽  
Stabilized Platform ◽  
And Control ◽  
The Mathematical Model

In this chapter, the author presents the problems of design of the robust automated system for stabilization and control of platforms with aircraft observation equipment. The mathematical model of the triaxial stabilized platform is developed. The procedure of synthesis of robust stabilization system based on robust structural synthesis is represented. The above-mentioned procedure uses loop-shaping approach and method of the mixed sensitivity. The matrix weighting transfer functions are obtained. The optimization programs in MatLab are developed. The developed procedures are approved based on the results of simulation by means of the appropriate Simulink model. The obtained results can be useful for unmanned aerial vehicles and aircraft of special aviation, which are used for monitoring technical objects and aerial photography. The technical contributions are procedures of the robust controller design represented as the flowchart. The proposed approach is validated by application of the theoretical suppositions to the concrete example and appropriate simulation results.

The Leveling Position Control of a Four-Axial Active Pneumatic Isolation System Using PWM-Driving Parallel Dual-On/Off Valves

2011 ◽  
Vol 110-116 ◽  
pp. 3176-3183 ◽  
Author(s):  
Mao Hsiung Chiang ◽  
Hao Ting Lin
Keyword(s):  
Trajectory Tracking ◽  
Vibration Isolation ◽  
Position Control ◽  
Controller Design ◽  
Sliding Mode ◽  
Tracking Performance ◽  
Trajectory Tracking Control ◽  
Isolation System ◽  
Adaptive Sliding Mode Controller ◽  
Novel Concept

This study aims to develop a leveling position control of an active PWM-controlled pneumatic isolation table system. A novel concept using parallel dual-on/off valves with PWM control signals is implemented to realize active control and to improve the conventional pneumatic isolation table that supported by four pneumatic cushion isolators. In this study, the cushion isolators are not only passive vibration isolation devices, but also pneumatic actuators in active position control. Four independent closed-loop position feedback control system are designed and implemented for the four axial isolators. In this study, on/off valves are used, and PWM is realized by software. Therefore, additional hardware circuit is not required to implement PWM and not only cost down but also reach control precision of demand. In the controller design, the Fourier series-based adaptive sliding-mode controller with H∞ tracking performance is used to deal with the uncertainty and time-varying problems of pneumatic system. Finally, the experiments on the pneumatic isolation table system for synchronous position and trajectory tracking control, including no-load and loading conditions, and synchronous position control with master-slave method, are implemented in order to verify that the controller for each cushion isolator can realize good position and trajectory tracking performance.

scholarly journals Position-Posture Control of Multilegged Walking Robot Based on Kinematic Correction

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Liang Zhang ◽  
Yaguang Zhu ◽  
Feifei Zhang ◽  
Shuangjie Zhou
Keyword(s):  
Position Control ◽  
Body Position ◽  
Control Process ◽  
The Body ◽  
Posture Control ◽  
Effective Control ◽  
Adjustment Process ◽  
Multilegged Walking Robot ◽  
Posture Adjustment ◽  
Robot Platform

Posture-position control is the fundamental technology among multilegged robots as it is hard to get an effective control on rough terrain. These robots need to constantly adjust the position-posture of its body to move stalely and flexibly. However, the actual footholds of the robot constantly changing cause serious errors during the position-posture control process because their foot-ends are basically in nonpoint contact with the ground. Therefore, a position-posture control algorithm for multilegged robots based on kinematic correction is proposed in this paper. Position-posture adjustment is divided into two independent motion processes: robot body position adjustment and posture adjustment. First, for the two separate adjustment processes, the positions of the footholds relative to the body are obtained and their positions relative to the body get through motion synthesis. Then, according to the modified inverse kinematics solution, the joint angles of the robot are worked out. Unlike the traditional complex closed-loop position-posture control of the robot, the algorithm proposed in this paper can achieve the purpose of reducing errors in the position-posture adjustment process of the leg-foot robot through a simple and general kinematic modification. Finally, this method is applied in the motion control of a bionic hexapod robot platform with a hemispherical foot-end. A comparison experiment of linear position-posture change on the flat ground shows that this method can reduce the attitude errors, especially the heading error reduced by 55.46%.

A Method for Recovering Linear Performance in Feedback Systems With Nonlinear Instrumentation

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
ShiNung Ching ◽  
Pierre T. Kabamba ◽  
Semyon M. Meerkov
Keyword(s):  
Linear Systems ◽  
Experimental Verification ◽  
Physical System ◽  
Controller Design ◽  
Magnetic Levitation ◽  
Feedback Systems ◽  
Sensors And Actuators ◽  
Controller Gain ◽  
Linear Controllers

The problem of controller design in linear systems is well understood. Often, however, when linear controllers are implemented on a physical system, the anticipated performance is not met. In some cases, this can be attributed to nonlinearities in the instrumentation, i.e., sensors and actuators. Intuition suggests that to compensate for this instrumentation, one can boost, i.e., increase, the controller gain. This paper formally pursues this strategy and develops the theory of boosting. It provides conditions under which the controller gain can be modified to offset the effects of instrumentation, thus recovering the performance of the intended linear design. Experimental verification of the technique developed is reported using a magnetic levitation device.

LOOKING FORWARD TO THE INTELLIGENT ELECTRICAL MACHINE: ELECTRONICS AND MACHINES COMBINE THEIR ABILITIES

1995 ◽  
Vol 05 (01) ◽  
pp. 45-63
Author(s):  
DIETRICH NAUNIN
Keyword(s):  
State Feedback ◽  
Position Control ◽  
Controller Design ◽  
Supply Voltage ◽  
Induction Machine ◽  
State Feedback Control ◽  
Electrical Machine ◽  
Precise Position ◽  
Electric Cars ◽  
Drive Systems

Electrical machines, more than 150 years old, have long been distinguished according to their mechanical structure and frequencies of their supply voltage (or current). This is not true any more after the electronic revolution. Since the fast development in power electronics as well as in control electronics these electronics can give any motor any desired speed-torque characteristic and any motor can become a servodrive having a very precise position control. By implementing digital control algorithms, mainly the cascaded, the state feedback or the cascaded state feedback control, and — if necessary, in addition — adaptive control procedures which compensate the variation of system parameters in the controller, the "intelligent electrical machine" — either with the synchronous or with the induction machine — is created. It is part of mechatronics. It can be installed in modern automated systems, in robots and tool machines, in all kinds of industrial drive systems as well as in locomotives and electric cars. Also modern methods like fuzzy logic and neural networks can be used. It seems that they will not create a second revolution in the control itself, but in the application areas of drives. They add some interesting features to the intelligent electrical machine and make it even more intelligent. They could also speed up the controller design in future.

Analysis of an Opto-Pneumatic Control System and Improvement of its Control Performance

1999 ◽  
Vol 11 (4) ◽  
pp. 251-257 ◽  
Author(s):  
Tetsuya Akagi ◽  
◽  
Shujiro Dohta ◽  
Hisashi Matsushita ◽  
Keyword(s):  
Control System ◽  
Position Control ◽  
Sliding Mode ◽  
Pneumatic Cylinder ◽  
Control Performance ◽  
Pneumatic Control ◽  
Servo Valve ◽  
Proposed Model ◽  
Control Scheme

This paper describes an analysis of an opto-pneumatic control system and an improvement of control performance of the system. The opto-pneumatic system consists of an optical servo valve, a pneumatic cylinder and a cart. First, we built an analytical model of the system considering a nonlinear friction where exists in sliding parts. And we confirmed the validity of the proposed model by comparing theoretical results with experimental results of the characteristics of optical servo valve and cart position control. Then, we applied a sliding mode control scheme compensating a steady-state disturbance to multi- position control and follow-up control of a cart. By computer simulation, we confirmed that the control performance of opto-pneumatic control system was improved by using this control scheme.

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