Single-rod Cylinder Research Articles

Position control of an er valve-cylinder system via neural network controller

A system of position control which uses a single-rod cylinder activated by an electrorheological (ER) valve is presented. Following the manufacture of a silicone oil-based ER fluid, a Bingham property of the ER fluid is first tested as a function of electric field in order to determine operational parameters for the ER valve.The ER valve with multi-channel plates is then designed and manufactured. Subsequently, pressure drops of the ER valve are evaluated with respect to the number of electrodes as well as the intensity of the electric fields. The ER valve—cylinder system is formulated and governing equations of motion for the system are derived. From the state-space model for the governing equations, a neural network control scheme is synthesized to achieve the position control of the cylinder system.Both regulating and tracking control responses are experimentally evaluated and presented in order to demonstrate the effectiveness of the proposed methodology.

パルス幅変調方式による空気圧シリンダの位置制御に関する一考察

This paper proposes a PWM (pulse-width-modulation) control of a pneumatic single-rod cylinder positioning system. In the system, the rod chamber pressure of the cylinder remains constant, and the head chamber pressure is controlled by two solenoid valves. The valves are under PWM mode control. In synthesizing the PWM servomechanism, the solenoid valves are characterized by a static characteristic equation incorporating the nonlinear elements caused by the switching time of the valve. The proposed PWM method can assign the steady-state duty ratios of the valves to the desired locations of their flow characteristics, which makes it possible for the system to avoid the dead-zone or the nonlinear region caused by the PWM solenoid valves. Also, a threshold near the desired position is set up so that the valves are closed at steady state. An experimental study of the proposed system is performed. These experiments verify the theoretical design work, and indicate that the proposed control system is feasible for pneumatic positioning.

高層ビル用油圧式制振装置の実用化検討と中規模実験

In this study, solutions were sought for two problems encountered in a large scale hydraulic optimal control active mass damper (AMD) system, spillover oscillation and low efficiency of cylinder stroke in a single rod cylinder. To prevent spillover oscillation without a larger system model or compromise of control performance, a control rule modified by the pole assignment method is proposed. The theoretical optimal control rule for a single rod cylinder was derived. The control method was shown valid by simulation. The experimental results showed close agreement with those of simulation and on the basis of which, a system test of AMD without real structure, was established.

Hydraulic Actuators Driven by Piezoelectric Elements. 3rd Report. Position Control Using Piezoelectric Pump and Hydraulic Cylinder.

This paper presents the working principle and the control performance of a hydraulic actuator system driven by a multilayered piezoelectric element. The main parts of the system are an accumulator, a reciprocating pump driven by the piezoelectric element, a single-rod cylinder and a control valve. The control valve is a variable throttle valve inserted between the rod-side and the head-side ports of the cylinder. When the pump is driven by its maximum voltage, the control valve is shut off, and the piston rod is then drawn into the cylinder by the working liquid supplied from the pump. Inversely, when the voltage becomes zero, the control valve is open, and the piston rod is pushed out of the cylinder by the working liquid supplied from the accumulator. Thus, the velocity of the rod is manipulated by changing the voltage applied to the pump. The experimental device was constructed using a piezoelectric element of 22 mm diameter and 55. 5 mm length, and a cylinder of 12 mm inner diameter and 6 mm rod diameter. The positioning controller was desinged using PD, feedforward and phase-lag compensators and a disturbance observer. Then, the positioning accuracies of about l0 μm and 50 μm were obtained for the external load forces of 0N and 60N, respectively, where the response frequency was about l0 Hz. Numerical simulations based on a set of mathematical models were also carried out to confirm the control performance of the proposed actuator system.

油圧式多機能シリンダの基本特性について

Recently, shortage of labor force has become a serious problem in mining industry, civil engineering and construction industry and so on. This is because of hard work load and its complication. Therefore, robotized machines have been required to improve labor-saving, safety and production in mining and construction works. Microcomputers have become very powerful in terms of communication capabilities and computing power. All that's at a lower cost. As a result of the availability of these powerful, low cost microcomputers, it is now possible to integrate them into oil hydraulic machines.In this paper, a vibration technique is employed to the oil hydraulic cylinder, which has multiple function. An apparatus of the experiment is an oil hydraulic controlled system with the two single-rod cylinders, proportional solenoid controlled valve and high speed on-off solenoid valve. First, the system is identified by mean of an expended least square method, and its pulse transfer function is determined. Next, the experiment is made with variation of the supply pressure and the frequency and the bias voltage under some levels of the constant load. As a results, the quantitative properties, namely, the vibration amplitude, the feed speed, the frequency, the maximum pushing force and the acceleration, are obtained.

On Linearized Coefficients for an Underlapped Servo-Valve Coupled to a Single-Rod Cylinder

On Linearized Coefficients for an Underlapped Servo-Valve Coupled to a Single-Rod Cylinder

A Digital Compensator Design for Electrohydraulic Single-Rod Cylinder Position Control Systems

A digital compensator using a forward algorithm, F(z−1), and a feedback algorithm, H(z−1), is developed for an electrohydraulic position control system incorporating an underlapped servovalve and a single-rod cylinder. The main problems encountered with designing such a closed-loop system are discussed, and it is shown how the filter coefficients may be easily determined for a particular class of open-loop transfer function. An excellent comparison between theory and experiment is obtained and it is deduced that one coefficient only need be changed in the forward algorithm for such gain-change dominant systems.

Use of a single-rod hydraulic cylinder in testing technology

1. The use of a single-rod differential cylinder in universal test machines makes it possible to significantly improve their dynamic parameters, especially in the area of high frequencies, at the same time combining a long stroke in the area of low frequencies, and also to simplify the control system, the design, and the method of producing the force exciter. 2. The universality of the differential hydraulic cylinder makes it possible to reduce the number of types and sizes of cylinders in the creation of a series of machines for static and fatigue machines in a wide range of frequencies and movements.