Position Control Of Hydraulic Cylinder Research Articles

Model prediction controller for penetration mechanism of seabed cone penetration test system

The system of seabed Cone Penetration Test (CPT) is a kind of equipment for offshore investigations. Seabed CPT is used to assess multiple physical properties of marine sediments. Constant-rate penetration mechanism is the core part of seabed CPT, which adopts dual-cylinder drive to penetrate the probe rod into the seafloor sediments at a constant speed (2cm/s). At present, the domestic CPT and its penetration equipment almost all rely on imports. In the process of system design, we found that the traditional PID control of the hydraulic cylinder position control accuracy is low, so we need to study higher precision position tracking control method to achieve uniform penetration of the probe rod. In this paper, a Linear Time-Varying Model Predictive Controller (LTV-MPC) is introduced, which can control two hydraulic cylinders to penetrate probe rod into the seabed sediment with smaller penetration rate error under the condition of changing penetration resistance.

A review on the position control of hydraulic cylinder for accuracy and response time

Hydraulic systems are used in heavy automation in a wide section of industry over other systems. Industrial automation such as sorting, clamping, and other manufacturing system require high accuracy but accurate positioning in less response time is hard to achieve, thus different approaches are implemented for different applications of the system. Traditionally piston stopped at the end terminals but with industrial development valves with mid-position are successfully being used. Thus with increasing industrialization, the need for a low-cost, accurate positioning and precise system is high in demand. These have become the key requirements in the industrial application in order to set economical and quality system. This paper reviews several research papers and their methodology to achieve accuracy in the system; both model-based and model-free approaches are studied.

Experimental Test and Feasibility Analysis of Hydraulic Cylinder Position Control Based on Pressure Detection

This paper studies hydraulic cylinder position adjustment controlled by an on–off valve. The aim of this paper is to develop a method of position control for a hydraulic cylinder based on input and output pressure under the mutual coupling feedback of the load and flow, especially in multi-actuator coupling control scenarios. This method can solve the problem of position evaluation and hydraulic cylinder tracking in relation to position detection without a displacement sensor and provide the possibility of automatic adjustment of hydraulic support in the process of intelligent mining. First of all, according to the flow continuity equation and Navier–Stokes equation, a flow model with inlet and outlet pressure is derived. Secondly, the effectiveness of the flow resistance characteristic curve of differential valve is verified by experimental and theoretical analysis. Finally, through experimental verification, when the system pressure is larger than 10 MPa, the error between the actual experimental data and the data calculated by the fitting algorithm is within 5%, which is consistent with the derived formula and proves the validity of the simulation model.

Research and Experimental Analysis of Hydraulic Cylinder Position Control Mechanism Based on Pressure Detection

This paper studies the precise position control of the hydraulic cylinder in the hydraulic support. The aim of this paper is to develop a method of hydraulic cylinder position control based on pressure and flow coupling, which takes the coupling feedback of load and flow into account, especially in the scene of cooperative control under the condition of multiple actuators and variable load. This method solves the problems of slow movement and sliding effect of hydraulic support in the traditional time-dependent hydraulic position control, as well as better realizes the intelligent and unmanned development of the fully mechanized mining face. First, based on the flow continuity equation and Newton Euler dynamic equation, the flow and stroke control model with the input and output pressure of hydraulic cylinder is established. Then, the effectiveness and correctness of the control model are verified by the comparison between the hydraulic system simulation software, AMESim, and the experiment. Finally, a test system is built. When the system pressure is large than 10 MPa, the error between the data determined by the fitting algorithm and the actual detection data is within 5%, which verifies the effectiveness of the theory and simulation model.

Electro-Hydraulic Proportional Position Control Using Auto Disturbance Rejection Based on RBF Neural Network

Large friction force and large dead zone are two typical nonlinear characteristics of electro-hydraulic proportional valve controlled hydraulic cylinder position control system. Aiming at those characteristics, a dead zone dynamic compensation algorithm is researched in order to reduce the lag time and control error. At the same time, a control strategy of radial basis function (RBF) neural network combined with auto disturbance rejection control (ADRC) is researched according to the impact of different conditions. The experimental result shows that the proposed algorithm improves performance of the electro-hydraulic proportional valve controlled hydraulic cylinder position control system. In positioning control experiment, the overshoot is 0 and the stability error is 0. In tracking control experiment, the lag time is reduced from the original 1.5 s to 0.2 s with no flat top phenomenon and the maximum error was reduced from 20 mm to 3 mm.

The use of digital hydraulic to the position control of hydraulic cylinder

The use of digital hydraulic to the position control of hydraulic cylinder

Nonlinear Position Control of Digital Hydraulic Cylinder Despite Disturbance

A nonlinear controller is presented for a digital hydraulic cylinder against disturbance. We first establish the nonlinear model of digital hydraulic cylinder position control system. Then a Lyapunov function and a nonlinear controller are presented. The controller designing problem is translated into the problem of solving a linear matrix inequality. The experiment results show that the controller proposed by this paper has much better performance than traditional one.

The position control of hydraulic cylinder based on high-speed on-off valve

This paper aims to research the position control of the hydraulic cylinder controlled by the high-speed on-off valve to realise the precise position control. The flow characteristic of the research on the relationship between the duty ratio and the average flow is researched. The mathematical model of the hydraulic cylinder is analysed and simulated with MATLAB/Simulink using the bulk-cavity-node method, and the compound algorithm of PD and speed feedforward-displacement feedback with the pulse width modulation (PWM) control is put forwarded. The position control of different control parameters is researched and the genetic algorithm is used to tune the control parameters. The hydraulic loop is set up to verify the simulation result with the optimised control parameters on the FESTO platform. The design methodology and control algorithm can be applied to other hydraulic system with position control requirement.

The Lower Extremity Exoskeleton Coordinated Control Method Based on Human Electromechanical Coupling

This paper has introduced electromechanical coupling characteristics in the lower extremity exoskeleton systems, considered model ,according to legs supporting gait when people walking, established the load torque compensation model , and a mathematical model of knee position control system which is made of the servo valve, hydraulic cylinders and other hydraulic components, designed hydraulic cylinder position control loop in case of existing load force interference compensation, and used the method of combining the PID and lead correction network for frequency domain design ,ensured system to meet a certain stability margin. The simulation results show that this position control method can servo on the knee angular displacement of normal human walking, reached a certain exoskeleton boost effect, at the same time, met the needs of human-machine coordinated motion.

Coordinated Control Method of the Portable Facility for Bearing Load Based on Human Electromechanical Coupling

This paper has introduced electromechanical coupling characteristics in portable facility for bearing load, considered model ,according to legs supporting gait when people walking, established the load torque compensation model , and a mathematical model of knee position control system which is made of the servo valve, hydraulic cylinders and other hydraulic components, designed hydraulic cylinder position control loop in case of existing load force interference compensation, and used the method of combining the PID and lead correction network for frequency domain design ,ensured system to meet a certain stability margin. The simulation results show that this position control method can servo on the knee angular displacement of normal human walking, reached a certain portable facility bearing load and assistant power effect, at the same time, met the needs of human-machine coordinated motion.

Energy-regulation based variable speed hydraulic cylinder position control system

Variable speed hydraulic control systems were widely used because of the good characteristic of power adaptive and energy-saving. But the dynamic characteristic of variable speed hydraulic control systems is slow, such systems are only suitable for the applications which don’t require fast dynamic response. To improve the dynamic characteristics of the variable speed hydraulic control systems, an energy regulation device was schemed out to be added on the systems, this will form a new type of hydraulic control system(energy-regulation variable speed hydraulic control system). The energy regulation device can absorb redundant oil fluid during system deceleration period, as well as release oil flow during system acceleration period. The composition of the energy regulation device and the energy-regulation variable speed hydraulic control was introduced, and the nonlinear math model of the whole system was derived. Digital simulation of the system was carried out and the simulation results shows that this type of system can improve the dynamic greatly while the energy cost is very little.

定圧力源システムにおける油圧シリンダの位置決め制御

定圧力源システムにおける油圧シリンダの位置決め制御

Sliding mode tracking control of a low-pressure water hydraulic cylinder under non-linear friction

This paper deals with a robust motion control of a low-pressure water hydraulic cylinder under non-linear friction. In order to ensure good tracking performance as well as to guarantee robustness, the sliding mode tracking control is utilized in combination with a non-linear friction compensator. Application of the scheme to a low-pressure water hydraulic cylinder position control has led to a significant reduction in tracking error when compared with the perfect tracking control scheme.

Sliding mode tracking control of a low-pressure water hydraulic cylinder under non-linear friction

This paper deals with a robust motion control of a low-pressure water hydraulic cylinder under non-linear friction. In order to ensure good tracking performance as well as to guarantee robustness, the sliding mode tracking control is utilized in combination with a non-linear friction compensator. Application of the scheme to a low-pressure water hydraulic cylinder position control has led to a significant reduction in tracking error when compared with the perfect tracking control scheme.

DEVELOPMENT OF WATER HYDRAULIC CYLINDER1 POSITION CONTROL SYSTEM

In this paper, the water hydraulic cylinder position control system, newly developed by authors, will be discussed. First, the outline of the water hydraulic servovalve and the components for cylinder position control system, as well as the points of control method of the water hydraulic system, are introduced. Next section discuses on the basic performance of the system: a horizontal cylinder position control; synchronizing control for two horizontal cylinders; and a basic performance of synchronizing control device which moves cylinders vertically. The control performance of these water hydraulic servo system is at the same level of that of the oil hydraulic servo system. For the synchronizing control for vertical cylinders, more practical issue, such as the influence of the eccentric load, is discussed.