Signed-Distance Fuzzy Sliding Mode Position Control for an Energy-Saving Electro-Hydraulic Control System

2013 ◽  
Vol 284-287 ◽  
pp. 2315-2319
Author(s):  
Mao Hsiung Chiang ◽  
Chung Chieh Cheng ◽  
Liang Wang Lee ◽  
Maoh Chin Jiang ◽  
Jhih Hong Lin

Electro-Hydraulic pump-controlled servo systems that have high energy-efficiency can serve as energy-saving system. This paper aims to investigate the servo performance of the electro-hydraulic pump-controlled systems driven by an AC servo motor with variable rotational speed. A constant displacement axial piston pump is used in this research. Thus, the new hydraulic pump-controlled system with an AC motor servo and a constant displacement axial piston pump is investigated for position control of hydraulic servo machines. For that, this paper also develops the control strategy, sign-distance fuzzy sliding mode control, which can simplify the fuzzy rule base through the sliding surface. The developed high response variable rotational speed pump-controlled systems controlled by SD-FSMC are implemented and verified experimentally for positioning control in different stroke and loading conditions.

2011 ◽  
Vol 308-310 ◽  
pp. 388-400
Author(s):  
Xiao Gang Zhang ◽  
Long Quan

In order to realize that an asymmetric flow piston pump can control an asymmetric differential cylinder, a proposal about the application of an asymmetric flow-distributing axial piston pump is put forward. The new type of piston pump can output the flows with two different values to control the movement of the differential cylinder directly in the closed circuit and realize much ideal result of the control of the differential cylinder by a single pump. Also a simulation model of the hydraulic pump is established under the circumstance of SimulationX software, considering the characteristics of the movement of an individual piston, the oil compressibility, and the flow distribution area changed with the rotation angle. The key data of the pump is defined by means of digital simulation. In particular, an analysis is made on the dimension of the unloading groove of the port plate and the characteristics of the flow pulse of the pump. Furthermore, an experimental model pump is manufactured, the basic performances of the pump is tested on the experimental platform at various rotatory speeds such as pressure, flow and noise, in the end the accuracy of the principle is verified.


Author(s):  
Pengcheng Qian ◽  
Zengqi Ji ◽  
Bihai Zhu

Axial piston pumps with port valves are widely used in applications that require high pressure and high power. In the present research, a new type of double-swash-plate hydraulic axial piston pump (DSPHAPP) with port valves is presented. The structure and working principle of the pump are discussed, and the balance characteristics of the pump are analyzed. A mathematical model of the pump flow distribution mechanism considering the leakage is established, based on which the effects of centrifugal forces acting on the port valves, working pressure, and rotational speed on the flow distribution characteristics are studied. A new method of varying the displacement of the pump that changes the phase relation of the two swash plates is proposed, and the principle and regulating characteristics of the variable method are studied. A detailed analysis of the forces and moments acting on the cylinder and the bearing reaction forces is presented. Finally, the relationship between volumetric efficiency and working pressure, and rotational speed and variable angle, is presented. It is revealed through an analysis that the working principle of the pump is feasible, and that the variable method can meet the requirements of varying the displacement of the pump. The characteristics of static balance and dynamic balance of the double-swashplate pump have the advantage of reducing vibration and noise. The research results also show that the reasonable matching of the working pressure and rotational speed can increase the pump's working performance to its optimum level.


Author(s):  
Qingcong Wu ◽  
Xingsong Wang ◽  
Fengpo Du ◽  
Ruru Xi

The applications of robotics and automation technology to the therapies of neuromuscular and orthopedic impairments have received increasing attention due to their promising prospects. In this paper, we present an actuated upper extremity exoskeleton aimed to facilitate the rehabilitation training of the disable patients. A modified sliding mode control strategy incorporating a proportional-integral-derivative sliding surface and a fuzzy hitting control law is developed to ensure robust and optimal position control performance. Dynamic modeling of the exoskeleton as well as the human arm is presented and then applied to the development of the fuzzy sliding mode control algorithm. A theoretical proof of the stability and convergence of the closed-loop system is presented using the Lyapunov theorem. Three typical real-time position control experiments are conducted with the aim of evaluating the effectiveness of the proposed control scheme. The performances of the fuzzy sliding mode control algorithm are compared to those of conventional proportional-integral-derivative controller and conventional sliding mode control algorithm. The experimental results indicate that the position control with fuzzy sliding mode control algorithm has a bandwidth about 4 Hz during operation. Furthermore, this control approach can guarantee the best control performances in term of tracking accuracy, response speed, and robustness against external disturbances.


Author(s):  
Chung-Chun Kung ◽  
Kuo-Ho Su

A novel adaptive fuzzy sliding-mode control (AFSMC) system for high-precision position control of a perturbed electrical servo drive is developed in this paper. The proposed AFSMC system is designed via the approximation ability of a fuzzy system to mimic the good behaviour of a total sliding-mode control (TSMC) system, which is designed without the reaching phase of a conventional sliding-mode control (SMC). In the developed system, a priori knowledge of the system information is not required. Moreover, the gradually increasing estimate upper bound, which may induce the control effort into saturation and excite unstable system dynamics in some conditions, would not exist. In the proposed controller, the adaptive tuning algorithms are developed in the sense of the Lyapunov stability theorem, so that system-tracking stability can be guaranteed. Finally, the effectiveness of the proposed control scheme is verified via the experimental results of a field-oriented control permanent magnet (PM) synchronous motor.


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