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The effects of temperature and rotating speed of a feeding screw on the key performance parameters (mass yield, energy yield, and energy densification index) of torrefaction in a stationary reactor...

This brief improves the motion precision of a pump-controlled electrohydraulic actuator with input saturation and heavy friction. A model-based adaptive commander filtering control (CFC) with the integration of an anti-windup auxiliary system and friction compensation is proposed. Firstly, CFC is designed to solve the problem of the “explosion of complexity” in the classic backstepping design technology, which reduces the online computation burden and is more suitable for industrial applications. Next, an auxiliary dynamic system is introduced to handle the effect of input saturation. The Nussbaum functions are adopted to avoid the derivative singularity of approximate saturation function and improve the anti-windup control performance. Moreover, the designed controller theoretically guarantees asymptotic stability, and the boundedness of all closed-loop system signals is guaranteed. Finally, using a modified continuous LuGre model, a friction compensator is designed in order to improve tracking precision. Comparative experimental results demonstrate the effectiveness of the proposed anti-windup and friction compensation approaches.

The sigma-1 receptor (σ1R) is a unique intracellular protein. σ1R plays a major role in various pathological conditions in the central nervous system (CNS), implicated in several neuropsychiatric disorders. Imaging of σ1R in the brain using positron emission tomography (PET) could serve as a noninvasively tool for enhancing the understanding of the disease's pathophysiology. Moreover, σ1R PET tracers can be used for target validation and quantification in diagnosis. Herein, we describe the radiosynthesis, in vivo PET/CT imaging of novel σ1R 11C-labeled radioligands based on 6-hydroxypyridazinone, [11C]HCC0923 and [11C]HCC0929. Two radioligands have high affinities to σ1R, with good selectivity. In mice PET/CT imaging, both radioligands showed appropriate kinetics and distributions. Additionally, the specific interactions of two radioligands were reduced by compounds 13 and 15 (self-blocking). Of the two, [11C]HCC0929 was further investigated in positive ligands blocking studies, using classic σ1R agonist SA 4503 and σ1R antagonist PD 144418. Both σ1R ligands could extensively decreased the uptake of [11C]HCC0929 in mice brain. Besides, the biodistribution of major brain regions and organs of mice were determined in vivo. These studies demonstrated that two radioligands, especially [11C]HCC0929, possessed ideal imaging properties and might be valuable tools for non-invasive quantification of σ1R in brain., Graphical abstract Of the two novel 11C-labeled sigma-1 receptor radioligands, [11C]HCC0929 has possessed better kinetic property and specificity, which could potentially accelerate preclinical research and medical development in sigma-1 receptor-related center nervous systems disease.Image 1

A thorough understanding of the internal flow dynamics inside a poppet valve makes sense for an improved control performance. Hence, a numerical simulation for the cavitating jet is performed with main concern on the cavitation-vortex interaction. The periodic cavitation structure, along with corresponding variation in vorticity distribution and large scale eddy, is presented for the quasi-steady flow from numerical results. As expected, cavitation inception exhibits great dependence on coherent structure, which is organized as paired vortex rings. Besides, cavitation is persistently located at core of vortex, indicating strong correlation between cavitation and vortex dynamics. The cavitation-vortex correlation is further discussed with analysis of vorticity transport equation, involving vortex stretching, dilatation and baroclinic torque terms. At incepting stage, vortex stretching is the dominant factor, responsible for vortex growth and the elliptical shape of cavitation ring. In comparison, the dilatation term could produce either enhancement or suppression in local vorticity, depending on the volumetric variation induced by cavitation. During the collapse stage, the bubble collapse creates baroclinic vorticity, and contributes to 3-dimensional vorticity. The most significant finding of the present study is the suppression of vorticity during the growing process of cavitation, contributing to an enhanced understanding of the cavitation-vortex interaction.

Nowadays, the emissions from conventional vehicles significantly contribute to increasingly serious environmental issues. In addition, the energy crisis and the low energy efficiency of conventional vehicles also offer a good opportunity to develop electric vehicles. Hybrid electric vehicles have better fuel economy compared to conventional vehicles, but they are just an interim step in vehicle development and pure electric vehicles are the ultimate goal. Currently, the technologies of hybrid electric vehicles can be found in numerous literature surveys, however there is a lack of published papers to present a comprehensive technical review for pure electric vehicles. In this study, the characteristics and typical models of energy sources of pure electric vehicles are firstly described. Then the existing pure electric vehicle types are depicted and the environmental impacts of the typical pure electric vehicles are evaluated. Moreover, energy management strategies for pure electric vehicles and charging technologies are investigated. The main challenges faced by pure electric vehicles and corresponding solutions are discussed, whilst the latest developments of pure electric vehicles are presented. The awareness of environmental issues and the energy crisis as well as the incentives from the governments of many countries continuously enhance the rapid development of pure electric vehicles.

Conventional cooling networks are usually operated in a parallel configuration. Although this configuration is easy operated, it results in inefficient use of water. A series configuration can effectively reduce water flow rate, while its arrangement is relatively complex, incurring more operating and capital cost. This paper proposes a water and energy conservation strategy to save energy cost and to simplify the network structure. Heat exchangers are arranged in series-parallel configuration to reduce the water flow rate for water conservation, and two kinds of installation conditions with or without static pressure drop are taken into account for energy conservation. A main-auxiliary pump structure is applied to reduce the operating consumption. The number of reuse branch for the economic performance is analyzed. Mixed-integer nonlinear programming based on a superstructure description is formulated by considering the configuration of pumps and heat exchanger networks simultaneously. Two case studies are employed to demonstrate the effectiveness of the proposed approach. The results show that the improved series-parallel configuration approach can save 10.9% of the total cost compared with the two-step sequential optimization and 4.7% compared with the simultaneous optimization method.

A hybrid Lagrange interpolation differential evolution algorithm (HLIDE) is proposed in this study for path synthesis of four-bar mechanisms. HLIDE combines two algorithms of differential evolution (DE) with Lagrange interpolation local search (LILS). LILS performs a local search in the neighborhood of the best individual to enhance the local exploitation capability of DE. In addition, an adaptive local search strategy is presented to further improve the efficiency of LILS. This technique can adaptively apply LILS based on the performance of LILS and DE in previous generations. To evaluate the efficiency and accuracy of HLIDE, five cases of path synthesis involving four-bar mechanisms were tested. Moreover, three well-known evolutionary algorithms, i.e., particle swarm optimization, teaching-learning-based optimization, and differential evolution, were implemented and compared in the five cases. Previous solutions for the same path generation problems by different evolutionary algorithms are summarized and compared in this study. Experimental results showed that HLIDE has significantly better performance in solving the synthesis problems of mechanisms when compared to other algorithms.

A combined experimental and numerical method is performed in order to investigate the flow pattern for cavitating jet through a poppet valve. Results show that coherent structure, which is organized as paired vortex structure, is widely involved in internal dynamics of the investigated jet flow. Its formation is governed by a similar mechanism, whereas its subsequent evolution shows variation close correlated to flow pattern. Generally, transition of coherent structure leads to noticeable alteration in flow pattern. In the present case, however, it is the subsequent evolution of coherent structure that plays a determinant role for flow pattern. For low pressure drop below 25 bar in poppet valve of 0.7 mm openness, coherent structure experiences a gradual collapse, and the laminar potential core is persistent along poppet surface. For moderate pressure drop, coherent structure undergoes a progressive intensification, and the laminar flow becomes partly disturbed as a waving pattern in the wake or a further periodic cavitating pattern. With pressure drop over 36 bar, vortex evolves fast into a cavitating bubble cluster, which involves strong interaction between coherent structures. Consequently, potential core experiences a sudden and aggressive fragmentation. In addition, three kinds of vortex pairing process are captured, which are demonstrated highly involved in evolution of coherent structure and at the same time exhibit some distinctive features from conventional paring process. Furthermore, the transition in flow pattern reveals and explains the piecewise flow-rate performance.

Poppet valve is widely used in oil hydraulics due to its simple and robust structure. With occurrence of cavitation, serious choking is possibly triggered in a poppet valve and its governing mechanism is yet unknown. In order to investigate cavitating jet, a compressible, two-phase method for cavitating flow is developed based on OpenFOAM, which (1) incorporates VOF phase-fraction interface capturing technique in an Eulerian framework; (2) involves special treatment for transonic case; (3) allows separate exhibition and analysis of examination of diverse influences on the fragmentation process of potential core; (4) is expected in due course to provide a detailed picture of the mechanisms that govern the choking formation. The numerical approach is combined with experiment to perform a systematic investigation of the choking phenomenon. Calculation results are shown to be generally consistent with experiment in terms of flow performance and cavity structure. Therefrom the following analysis and discussion are performed. (1) The choked flow is investigated based on development in cavitation structure with respect to pressure drop. (2) The computational and experimental results are combined to provide a comprehensive evolution process of the jet with increase in pressure drop. It clarifies that the cavitation inception is close associated with transition in flow pattern. (3) The jet dynamics is divided into several stages according to gradual development, which is in detailed discussed separately. (4) Results also confirm the periodic performance of cavitation. The cyclic shedding of bubble cluster is utilized to interpret the disintegration of potential core.

Magnolol (Mag), an effective natural compound isolated from the stem bark of Magnolia officinalis, was found to have the potential for antitumor activity by inducing apoptosis in tumor cells. However, the effect of Mag on renal carcinoma cells and its molecular mechanism are unexplored. Our study provided evidence that Mag induced apoptosis in 786-O and OS-RC-2 cell lines via the mitochondrial pathway and cell cycle arrest. In this work, we found that Mag induced morphological changes and inhibited the proliferation of 786-O and OS-RC-2 cells in a dose- and time-dependent manner but exerted no notable inhibitory effects on normal human renal proximal tubular (HK-2) cells. Treatment with Mag suppressed the migration and invasion ability of renal carcinoma cells. Moreover, Mag caused the openness of mPTP, the accumulation of intracellular ROS and decreased △Ψm, leading to mitochondrial dysfunction. However, pretreatment with the antioxidant N-acetyl cysteine (NAC) reversed the apoptosis induced by Mag and decreased the generation of ROS. In addition, the increased proportion of the G1/G0 phase indicated that Mag caused cell cycle arrest. Further analyses suggested that magnolol-induced apoptosis was related to the abnormal expression of p53, Bax, Bcl-2, cytochrome c and caspase activation. Together, the results above revealed that Mag had antitumor effects in renal carcinoma cells via ROS production as well as cell cycle arrest and the apoptotic mitochondrial pathway was suppressed in part by NAC.

Differential evolution (DE) is a simple yet powerful evolutionary algorithm that has been used to solve various complex optimization problems in numerous engineering fields. However, DE has some problems, such as premature convergence and sensitivity to parameter settings. To improve the performance of DE and extend its application, an adaptive differential evolution with the Lagrange interpolation argument algorithm (ADELI) is proposed in this paper. To accelerate the convergence speed of DE, a local search with Lagrange interpolation (LSLI) is introduced into DE. LSLI performs a local search in the neighborhood of the best individual in the current generation to enhance the exploitation capability of DE. Meanwhile, an adaptive argument strategy is presented to adaptively determine whether to use LSLI in terms of its performance in the previous generation, which can balance the global exploration capability and the local exploitation capability of ADELI. To verify the feasibility and effectiveness of ADELI, 30 test functions in the CEC 2014 benchmark sets with different dimensions were simulated. Moreover, a path synthesis problem was also optimized. The results demonstrated that ADELI considerably outperforms other EAs in most functions and obtains the most accurate solution among the compared algorithms in the application of path generation.

As an electro-hydraulic servo shaking table takes on an elastic load in a vibration test of a 2-mass dynamic system, a mutual coupling effect is exerted between the shaking table and the specimen, which will form a resonant system to weaken the dynamic characteristics of the system. As required by the system bandwidth, the resonant system contains a resonance valley and a resonance peak, and its amplitude commonly surmounts the stability range of the system’s acceleration amplitude. In this article, the resonance phenomenon is analyzed, and the structure and the parameters of the three-state controller are designed on the basis of a pole assignment system. The adaptive spectral line enhancer is adopted to suppress the resonant valley, and the power spectrum is analyzed to experimentally verify that it exerts an anti-resonance effect.

In order to design a controller, mathematical model is usually derived first, either from physical laws or by employing a system identification technique. Physical laws may not fully define the system because of the existing uncertainties and/or difficulty to accurately model certain phenomenon. Therefore, the resulting controller may be too conservative. In this article, we design a low-bandwidth controller for an electro-hydrostatic actuator positioning system based on a system identification technique. The designed controller is also linear, fixed-gain and robust to system uncertainties. A set of offline parametric linear identifications are performed under different conditions, including various environmental stiffnesses, levels of actuator internal leakage, viscous dampings and load masses. The obtained family of identified models is then used to design a quantitative feedback theory controller that satisfies given tracking and stability specifications. In addition, the performance of the controller is examined against another quantitative feedback theory controller that is designed for the same system using physical laws. The performances of two controllers are examined on a test rig. Experimental results show that both quantitative feedback theory controllers are capable of maintaining actuator position within acceptable response envelope. However, the controller designed based on physical laws has higher bandwidth and therefore is more conservative.

In swing system of excavators, energy recuperation and hybrid actuation is desirable to improve energy efficiency because of its characteristic large inertial load and cyclic operation. Numerous st...

With the increasing concern over global energy crisis, energy saving in pumping units is becoming a significant subject. In terms of energy-saving and working efficiency, hydraulic pumping units outperform conventional pumping units. In this paper, a novel hydraulic pumping unit is proposed to overcome the existing drawbacks of conventional pumping units and present hydraulic pumping units. Firstly, this novel hydraulic pumping unit adopts a balanced mechanical structure, which means two oil wells are used in this system and the weight of their sucker rods can balance each other through the symmetrical arrangement. This kind of structural design not only saves the nominal power but also allows the system to continuously pump oil. Another feature of this hydraulic pumping unit is that it adopts the electro-hydraulic proportional load-sensing control technology, which makes the pressure and flow rate of the pump adapt to the requirement automatically in real time. The double wells of the system work alternatively under the normal condition and any one can work alone when the other needs maintenance, which improves the operating rate of pumping oil. After the main system parameters are calculated, conclusion can be drawn that both the nominal and operating power of this hydraulic pumping unit are relatively low. The model of the whole system is built based on mathematical dynamics and AMESim environment, and simulation results demonstrate that the proposed hydraulic pumping unit can achieve remarkable energy-saving performance.

A bilateral teleoperator allows operators to use a master manipulator to interact with the environment via a slave manipulator. It can be used in remote, hazardous or inaccessible situations. Although numerous bilateral teleoperation studies have been conducted on electrical actuators, research on hydraulic actuators, especially research on electro-hydrostatic actuators (EHAs), a class of pump-controlled systems, is currently limited. In bilateral teleoperation, one issue concerns how to tune the controller parameters with regard to stability and transparency in the presence of uncertainty. In this paper, an approach based on quantitative feedback theory (QFT) that provides guidance on controller parameter selection during the bilateral teleoperation of EHAs is introduced. Parametric uncertainties in dynamics of human operators, master manipulators and environments are described in templates to compute bounds quantitatively, and trade-offs between stability and transparency are visualized. Four commonly used bilateral control schemes are exemplified using this method: force reflection (FR), position error (PE), shared compliant control (SCC) and force reflection with passivity (FRP). The bilateral controllers are tuned through simulations and are validated through contact experiments involving both soft and hard environments. Given its simple structure and excellent level of transparency, FR is found to be the most suitable scheme of the four for teleoperations of EHAs.

This brief presents design and experimental evaluation of a fixed-gain position controller for the class of electrohydrostatic actuator that is tolerant to actuator internal leakage fault and robust to various environmental stiffnesses and system parametric uncertainties. Built upon quantitative feedback theory, the proposed controller is designed according to stability and tracking specifications, considering actuator internal leakage as one of the uncertain phenomena. The controller is also augmented with a friction compensator to alleviate the parasitic effect of dry friction in the hydraulic cylinder and further improve the tracking performance. The ability of the augmented controller in maintaining the actuator position within acceptable response envelopes is demonstrated in both simulations and experiments. More specifically, the experimental results show that the steady-state error of various step input responses remains within 0.1 mm despite an internal leakage flow rate as high as 8.5 L/min.

In this paper, we propose a method for performing electricity price execution inspection by using a variational autoencoder technology in deep learning. The variational auto encoder based anomaly detection algorithm(VABAD) can be used both as a discriminant model and as a feature of the generation model, which effectively solves the calculation problem of multiple heterogeneous parameters of current electricity price inspection implementation. The reconstruction probability is a probabilistic measure that takes into account the variability of the distribution of variables. It is used by autoencoder based anomaly detection methods. Experimental results show that the proposed method has been validated and compared to the existing approaches. The databases used in this paper come from Power Marketing System that occurred in Liaoning, China in 2015.

Characterized by high power-to-weight ratio, modularity and energy efficiency, electro-hydrostatic actuators (EHAs) have been successfully applied to aircrafts and submarines, where high precision and repeatability are in high demand. The position tracking performance, however, can be inevitably affected by parametric uncertainties and uncertain nonlinearities. Model inaccuracy or system variations normally require a large loop gain to achieve robust performance, which leads to over-design. Leakage in the fluid power system decreases steady-state accuracy, and friction in the actuator degrades the transient performance or even causes stick-slip motion at low speeds. Furthermore, the system may exhibit limit cycle (or hunting) due to Stribeck friction and integral action. This paper proposes a robust high precision position control strategy incorporating leakage and friction compensation for EHAs. Quantitative feedback theory (QFT) is applied to design a robust controller that satisfies the prescribed performance specifications without over-design, considering model inaccuracy and system variations. The internal leakage is subsequently compensated based on experimental data instead of incorporating an integrator in the controller; hence, limit cycle is avoided, and response speed is improved. Friction in the actuator is identified based on the LuGre friction model and compensated through an observer in the loop. Friction variation and load fluctuation are considered to be output disturbances to be suppressed by the QFT controller. The QFT controller with leakage and friction compensation scheme is verified through experiments on a typical EHA. Both the steady-state and transient position tracking performances are greatly improved.

In order to explore the types of ultrasonic rolling tool head used in ultrasonic rolling and finishing processing device, ANSYS Workbench is taken as a tool to simulate the machining process of ultrasonic rolling processing through transient dynamic analysis, and the maximum residual stress distribution and stress concentration of 45 steel workpiece are analyzed. Based on the simulation result, the ball-type ultrasonic rolling tool head is selected in this work. In addition, the transient dynamics module of ANSYS Workbench is also used to simulate the ultrasonic rolling tool head of different structure parameter, in that way, the accurate and reasonable structure parameters of rolling components of ultrasonic rolling tool head can be achieved. The results of this work show that a ball-type ultrasonic rolling tool head of a diameter of 8mm can make the maximum residual stress minimum and stress concentration slightest under the condition of normal processing of the 45 steel workpiece. In other words, it suggests that this ultrasonic rolling tool head can produce the best surface quality of 45 steel workpiece.

In this paper, a new model of particle yield stress including cohesive strength is proposed, which considers the friction and cohesive strength between particles. A calculation method for fluidization process of liquid-solid two-phase flow in compact packing state is given, and the simulation and experimental study of fluidization process are carried out by taking the sand-water two-phase flow in the jet dredging system as an example, and the validity of the calculation method is verified.

In order to improve the activation of the mirror neuron system and the ability of the visual-cued motor imagery further, the multi-stimuli-cued unilateral lower limb motor imagery is studied in this paper. The visual-auditory evoked pathway is proposed and the sensory process is studied. To analyze the visual-auditory interactions, the kinesthetic motor imagery with the visual-auditory stimulus, visual stimulus and no stimulus are involved. The motor-related rhythm suppression is applied on quantitative evaluation. To explore the statistical sensory process, the causal relationships among the functional areas and the event-related potentials are investigated. The results have demonstrated the outstanding performances of the visual-auditory evoked motor imagery on the improvement of the mirror neuron system activation and the motor imagery ability. Besides, the abundant information interactions among functional areas and the positive impacts of the auditory stimulus in the motor and the visual areas have been revealed. The possibility that the sensory processes evoked by the visual-auditory interactions differ from the one elicited by kinesthetic motor imagery, has also been indicated. This study will promisingly offer an efficient way to motor rehabilitation, thus favorable for hemiparesis and partial paralysis patients.

Since there is a symbiotic and competitive relationship between microorganisms in the same ecological niche, fungal defensins have been found to be important resources for antimicrobial peptides. Here, a fungal defensin, triintsin, was characterized in a clinical isolate of Trichophyton interdigitale from a patient with onychomycosis. The comparison of its genomic and mRNA sequences showed the gene organization and structure of three coding exons separated by two introns. The precursor peptide of triintsin contained 85 amino acid residues, which were composed of three parts including an N-terminal signal domain of 21 residues, a pro-peptide of 47 residues that ended at lysine-arginine and a mature peptide of 38 residues at the C-terminus. The 3D-structure established by homology modeling revealed that triintsin presented a representative typical cysteine-stabilized α-helical and β-sheet fold. The reductive linear peptide of triintsin was obtained by chemical synthesis. After cyclization to form three pairs of disulfide bonds, the oxidative-type peptide displayed broad-spectrum antimicrobial activity against both gram-positive and gram-negative bacteria but also showed anti-fungal activity. Moreover, triintsin can effectively inhibit the growth of clinical strains. Altogether, the peptide is a human pathogenic fungus-derived defensin with broad-spectrum antimicrobial activity.

Drop-on-demand (DOD) printing is widely used in bioprinting for tissue engineering because of little damage to cell viability and cost-effectiveness. However, satellite droplets may be generated during printing, deviating cells from the desired position and affecting printing position accuracy. Current control on cell injection in DOD printing is primarily based on trial-and-error process, which is time-consuming and inflexible. In this paper, a novel machine learning technology based on Learning-based Cell Injection Control (LCIC) approach is demonstrated for effective DOD printing control while eliminating satellite droplets automatically. The LCIC approach includes a specific computational fluid dynamics (CFD) simulation model of piezoelectric DOD print-head considering inverse piezoelectric effect, which is used instead of repetitive experiments to collect data, and a multilayer perceptron (MLP) network trained by simulation data based on artificial neural network algorithm, using the well-known classification performance of MLP to optimize DOD printing parameters automatically. The test accuracy of the LCIC method was 90%. With the validation of LCIC method by experiments, satellite droplets from piezoelectric DOD printing are reduced significantly, improving the printing efficiency drastically to satisfy requirements of manufacturing precision for printing complex artificial tissues. The LCIC method can be further used to optimize the structure of DOD print-head and cell behaviors.

The noise from the cooling tower has a great influence on psychological performance of human beings. The cooling tower noise mainly consists of fan noise, falling water noise and mechanical noise. This thesis used DES turbulence model with FH-W model to simulate the flow and sound pressure field in cooling tower based on CFD software FLUENT and analyzed the influence of different kinds noise, which affected by diverse factors, on the cooling tower noise. It can be concluded that the addition of cooling water can reduce the turbulence and vortex noise of the rotor fluid field in the cooling tower at some extent, but increase the impact noise of the liquid-gas two phase. In general, the cooling tower noise decreases with the velocity ratio of liquid to gas increasing, and reaches the lowest when the velocity ratio of liquid to gas is close to l.

Motor function rehabilitation is very urgent for patients. Motor imagery is an efficient way for rehabilitation. To achieve the supervision of multiple rehabilitation targets simultaneously, the promotion of multi-class motor imagery classification accuracy is critical. In this paper, a multi-class classification method is proposed by utilizing singular value decomposition and deep boltzmann machine. Singular value decomposition is applied to suppress the artifacts and acquire the channel-individual characteristics. The deep boltzmann machine is employed to extract and model the characteristics and achieve the motor imagery classification. Results demonstrate that the proposed method has achieved a 14.2% higher classification accuracy than the common spatial pattern on average. This results are further validated by the statistical methods, which present a significant difference (p < 0.05). The proposed method is favorable for promoting the multi-class motor imagery classification efficiency.

Montmorillonite calcium (MMT-Ca) was functionalized with cetyltrimethylammonium bromide (CTAB) via cationic exchange effects. Compared with MMT-Ca, the resulting CTAB functionalized MMT-Ca (CTAB/MMT-Ca) greatly increased the oxidation peak current of sunset yellow, indicative of strong signal enhancement effects. The oxidation mechanism was studied, and one electron was transferred during the oxidation of sunset yellow. The influences of pH value, mass ratio of CTAB to MMT-Ca, amount of CTAB/MMT-Ca, and accumulation time were studied on the oxidation signal of sunset yellow. As a result, a highly-sensitive, rapid and simple electrochemical method was newly developed for the determination of sunset yellow. The linear ranger was from 2.5 to 200 nM, and the detection limit was as low as 0.71 nM after 1-min accumulation. This method was applied in soft drink samples, and the detected results consisted with the values that obtained by high-performance liquid chromatography.

Electrohydrostatic actuators (EHAs), as a class of pump-controlled hydraulic actuators, are known for energy efficiency and easy maintainability. Thus, they can be widely used in the situations where actuating pressure/force control of hydraulic actuators is essential. Examples are automotive active suspension, deep-drawing press, molding machine, and vibration isolation. However, a leaky piston seal in an EHA system can be especially problematic as it is not visually detectable, but causes internal leakage flowing across actuator chambers impairing the performance. This paper employs quantitative feedback theory (QFT) to design a robust fixed-gain linear actuating pressure controller that is tolerant to actuator internal leakage. Since QFT captures uncertainties by templates, representing frequency responses of the plant on Nichols chart, the first step, to design a QFT controller, is to establish plant templates. In doing so, a set of offline parametric system identifications are implemented, and the family of identified models, providing frequency responses, are used to design the QFT fault-tolerant controller. The controller also satisfies the prescribed design tolerances on tracking, stability and sensitivity (disturbance rejection at plant output) under different conditions, including various levels of actuator internal leakage, environmental stiffnesses, and load masses. The ability of the controller to maintain actuating pressure within the acceptable response envelope is demonstrated in experiments. The experimental results show that the system specifications are satisfied despite internal leakage up to 12 L/min.