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A novel concept of modular bistable electromagnetic actuator in valve operation is numerically analysed, designed and experimentally tested. The actuator takes advantage of permanent magnets for assuring stable positions of the valve body and field coils for control of the valve operation. The paper presents the basic concept of the actuator together with its numerical investigation for the case of...
Cornea transplantation surgery needs a highly skilled ophthalmologist due to the requirement of precise positioning and the plasticity of a cornea. In this paper, we propose a cornea holding device, which fixes the relative position between a donor cornea and a patient cornea. The proposed device prevents the slipping or deformation of the corneas during transplantation surgery. The cornea holder...
In this paper, a nonlinear control approach is presented for an electro-pneumatic clutch actuator for heavy trucks. A clutch is required at start-up or during gear shifts to disconnect the combustion engine from the gear box. This automated actuator provides the necessary actuation force according to the large torque transmitted through the power train. Based on a control-oriented system representation,...
The current bus brake system, that consists of two parts, air brake and exhaust brake. The exhaust brake system not enough to replace the air brake system. This research focuses on the new backup brake mechanism, using several valves and backup compressed air accumulators are inserted into the main brake system to provide brake force. When air brake failure, backup system can be using slow down and...
Maglev train is a new type of green environmental protection urban rail transit. Its security and reliability are the key issues which must be considered in the future development. In this paper, the working principle of the braking system in maglev train is comprehensively analyzed. By analyzing the characteristics of the braking system, the fault tree (FT) is employed to establish the fault model...
Based on the working principle of the electrohydraulic proportional control system of the working device of the demolition robot, the co-simulation model of the system is established by means of ADAMS and MATLAB. The study of the dynamic characteristics of the system was done, with applying traditional PID control strategy and sliding mode variable structure control respectively, considering the change...
Aiming at the aircraft skin inspection robot with double frames, a novel adsorption system is designed, in which the adsorption force between the suction cup and the surface of the aircraft is determined by the curvature change. In order to guarantee an optimal adsorption of the robot on the surface during the movement, the principal object is to determine the minimum value of the adsorption force...
This paper discusses modeling and nonlinear control of a joint antagonistically actuated by two pneumatic, artificial muscles. A single model of the whole system is obtained by a combined physical and phenomenological modeling approach. The combined model for the joint, the muscles and the proportional valves results in a nonlinear, affine-in-control system description. The model is used to derive...
State of art upper limb prostheses lack several degrees of freedom (DoF) and force the individuals to compensate for them by changing the motions of their arms and body. Such movements often yield to articulation injuries, nonetheless these could be prevented by adding DoFs, for instance, an articulated passive wrist. Available stiff or compliant wrists with passive flexion/extension and/or radial/ulnar...
In this paper, the modeling and prescribed performance control (PPC) problem is investigated for cold rolling mill system. First, considering the measurement delay and disturbances in practical process, a mathematical model is established for the cold rolling mill hydraulic automatic gauge control (HAGC) system. Then, based on a state transformation with the performance index function, a predefined...
Inflatable manipulators open new trends in robotic applications. In this paper, a new inflatable actuator to articulate a long-range inflatable robotic arm, is presented. Completely made of high strength fabric, its low mass leads to large force-weight ratios and a stroke almost equal to twice its overall length. The operation principle, as well as the relations among the displacement, the pressure...
Improving fuel economy and reducing the Greenhouse-Gas emissions have been the determining factors in the development and implementation of innovative automotive technologies. Engine thermal management is one of the research fields that tries to solve these issues. Thermal management can be applied when controlling temperatures in different cooling circuits with an electronically actuated valve, which...
By the nature of their physicality, conventional push-buttons provide raised edges and click feel that support localization and confirm actuation, even in the absence of vision. Though touchscreens augmented with modulated traction forces can render certain haptic cues, these cues are not sufficient to support many of the types of user interaction available through push-buttons. In this paper we introduce...
A pneumatic cylinder with an embedded magnetorheological (MR) brake has been developed. The new hybrid actuator benefits from the advantages of MR-brakes and pneumatic cylinders. It can apply forces using compressed air and can resist external forces using the MR-brake. The embedded brake enables dealing with challenges of using compressed air in precise positioning of the piston anywhere in its stroke...
In this paper, sampled-data repetitive learning control of electro-hydraulic actuator used in lower limb exoskeleton for rehabilitation is addressed. The controller is proposed entirely in the discrete-time domain. First, the discrete-time model of the electro-hydraulic actuator is derived by direct discretization using Euler approximation, where the equivalent mass and force acted on the electro-hydraulic...
The Pantograph-Catenary system(PAC) is the most crucial and vulnerable part in the high-speed train. During the high-speed movement of locomotive, the conventional passive control would cause various malfunction of the PAC system. Because the passive control does not have sufficient ability to avoid the dynamic variation of the contact force between carbon-plate and catenary wire. Therefore, this...
For the rolling system, it should be a multi-variable, strong disturbance and coupled nonlinear system. As the precondition of ensuring the precision of strip thickness, it is necessary to ensure that the system is robust. The controller should be able to suppress the disturbance of the system and remain the system stable under the uncertain parameters. Taking into account the complexity of the system,...
Stiction in control valve is one of the long-standing and common problems in the process industries, which accelerates equipment wear and even affects the stability of closed-loop systems. A valve stiction model is proposed to describe the dynamic feature of sticky valve. To detect and quantify valve stiction, a bootstrap Hammerstein system identification procedure is proposed. Through the identified...
This paper presents a modified nonlinear pneumatic model for pneumatic force servo systems. The modified model is proposed in order to estimate pressures accurately for both chambers of a pneumatic cylinder by adopting flow coefficient maps, which is different from a conventional model whose flow coefficient is constant. The simulated data from the model is also compared to the experiment result and...
Proportional valve-controlled electro-hydraulic position servo system has advantages of low cost and high dependability, but the friction of proportional valve restricts its application in industrial control system. In this paper, the model of proportional valve-controlled electro-hydraulic positon servo system has been established. Aiming at the friction in position servo system, the theoretical...
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