汤峪二原子自压喷灌工程支管破裂原因探索与对策

汤峪二原子自压喷灌工程支管频繁破裂,对其原因进行分析,得出支管破裂主要是因为支管管材质量不佳、节制控制系统不尽合理造成的;对其支管节制系统进行设计,提出改换支管管材,调整节制控制系统,可使喷灌工程重新恢复正常运行。结果可为类似工程提供参考。

A New Tuning Method for Two-Degree-of-Freedom Internal Model Control under Parametric Uncertainty

Internal model control （IMC） yields very good performance for set point tracking, but gives sluggish response for disturbance rejection problem. A two-degree-of-freedom IMC （2DOF-IMC） has been developed to overcome the weakness. However, the setting of parameter becomes a complicated matter if there is an uncertainty model. The present study proposes a new tuning method for the controller. The proposed tuning method consists of three steps. Firstly, the worst case of the model uncertainty is determined. Secondly, the parameter of set point con- troller using maximum peak （Mp） criteria is specified, and finally, the parameter of the disturbance rejection con- troller using gain margin （GM） criteria is obtained. The proposed method is denoted as Mp-GM tuning method. The effectiveness of Mp-GM tuning method has evaluated and compared with IMC-controller tuning program （IMCTUNE） as bench mark. The evaluation and comparison have been done through the simulation on a number of first order plus dead time （FOPDT） and higher order processes. The FOPDT process tested includes processes with controllability ratio in the range 0.7 to 2.5. The higher processes include second order with underdarnped and third order with nonminimum phase processes. Although the two of higher order processes are considered as difficult processes, the proposed Mp-GM tuning method are able to obtain the good controller parameter even under process uncertainties.

Calculation method for trajectory following control for autonomous vehicles

The current literature lacks uniform calculation methods for following trajectory control for autonomous vehicles,including the calculation of errors,determination of tracking points,and design of feedforward controllers.Hence,a complete calculation method is proposed to address this gap.First,a control equation in the form of an error is obtained according to the dynamic equation of the vehicle coordinate system and the trajectory following model.Secondly,the deviation of the vehicle state is obtained according to the current vehicle s state and the following control model.Finally,a linear quadratic regulator(LQR)controller with feedforward control is designed according to the characteristics of the dynamic equation.With the proposed LQR,the simulation of computational time,anti-interference,and reliability analysis of the trajectory following control is performed by programming using MATLAB.The simulation outcomes are then compared with the experimental results from the literature.The comparison indicates that the proposed complete calculation method is effective,reliable,and capable of achieving real-time and anti-interference following control performance.The simulation results with or without feedforward control show that the steady-state error is eliminated and that good control performance is obtained by introducing feedforward control.

Optimal Trajectory Planning of the Dual Arm Manipulator Using DAMM

This paper presents an optimal trajectory planning method of the dual arm manipulator using Dual Arm Manipulability Measure （DAMM）. When the manipulator carries an object from a certain position to the destination, various trajectory candidates could be conskied. TO select the optimal trajectacy from the several candidates, energy, time, and the length of the tmjecttay could be utilized. In order to quantify the carrying effidency of dual-arms, DAMM has been defined and applied for the decision of the optimal path. DAMM is defined as the interaction of the manipulability ellipsoids of the dualarras, while the manipulability measure irdicates the relationship between the joint velocity and the Cartesian velocity for each ann. The cast function for achieving the optimal path is defined as the Summation of the distance to the goal and inverse of this DAMM, which aims to generate the efficient motion to the goal. It is confirmed that the optimal path planning keeps higher manipulability through the short distance path by using computer simulation. To show the effectiveness of this cooperative control algorithm experimentally, a 5-DOF dual-ann robot with distributed controllers for synchronization control has been developed and used for the experiments.

Employer Branding Management As A Strategic and Organizational Control Tool

The issue of employer branding has always had an intrinsic interdisciplinary content, since it builds a bridge for cross-fertilization between different disciplines （strategic marketing, strategic management, and human resources management）. This paper presents employer branding as an approach based on effective strategic organizational resources and a precise employer branding management process. In this paper, the target is to define a possible frame in order to interpret employer branding techniques as control and regulation mechanisms. Control in organizations has long been a topic of interest for researchers and practitioners, alike who generally recognize that control mechanisms are needed to ensure that organizations may achieve their goals. It has been carried out a field work on the Italian Aeronautical Meta district, that generates annual revenues equal to EUR 8.7 billion and employees 36,300 people, of whom approximately 10% are employed in the space sector. Through this field work, the intention aim is to understand if and how employer branding may create, enforce, and set up internal and shared meaning and values. In particular, stemming from the empirical research＇s evidences, this paper tries to conceptualize employer branding as a factor to persuade and influence the way that organizational actors enact in a socially constructed context. In this effort, the aim is to understand how managers may affect meanings, values goals, and opinions through an effective action on employer branding that can play a crucial role in affecting sense-making processes, meanings, interpretations of the symbolic environment. The paper therefore opens up to new horizons, since it embraces a new application for employer branding, considering it as a modern control system and proposing an innovative approach in managerial control, founded on organizational identity as a key concept in an organizational citizenship＇s perspective

Combinative Approaches of Chemistry, Pharmacology and Toxicology for the Optimal Pharmaceutical Preparation of an Anti-arthritic Chinese Medicine Formulation QFJBT

Objective Qing Fu Juan Bi Tang(QFJBT)is an anti-arthritic Chinese medicine formula consisting of five herbs:Aconiti Lateralis Radix Praeparata(Fu Zi,附子),Sinomenii Caulis(Qing Feng Teng,青风藤),Astragali Radix(Huang Qi,黄芪),Paeoniae Radix Alba(Bai Shao,白芍)and Moutan Cortex(Mu Dan Pi,牡丹皮),which have well-established histories of use for treatment of rheumatic and arthritic diseases.We intended to establish the optimized and standardized pharmaceutical procedures and manufacturing processes for the pilot production of QFJBT to develop it as a novel botanical drug product for treatment of rheumatoid arthritis(RA).Methods The combinative approaches of chemical assessment,toxicological and pharmacological evaluation were explored to define the pharmaceutical preparation of QFJBT.Results The optimized and standardized pharmaceutical procedures and manufacturing processes for the pilot production of QFJBT were established in terms of greatest chemical contents of bioactive constituents,potent anti-inflammatory and antinociceptive activities,and favorable safety profile.Quality analysis of the pilot product of QFJBT by high-performance liquid chromatography(HPLC)demonstrated that the chromatographic fingerprint profiles of three batches of QFJBT were basically identical and the contents of four characteristic and bioactive markers were relatively consistent.General toxicological studies showed a favorable safety profile of QFJBT.The maximum tolerated single dose of QFJBT was determined in both sexes of rats to be 33.63 g/kg body weight which is equivalent to 346 times of clinical dose.In the chronic oral toxicity study,the results of laboratory investigation showed that QFJBT at doses of 3.89,6.80 and 9.72 g/kg body weight(equivalent to 40,70 and 100-fold clinical doses,respectively)caused no changes in all hematological parameters and blood biochemical parameters of rats.No mortality or specific toxic responses were observed in animals after three months of repeated dosing with QFJBT.Conclusion The optimized and standardized pharmaceutical and manufacturing processes for the production of QFJBT have been successfully screened and identified through established rigorous in-process controls.

Dynamic surface control-backstepping based impedance control for 5-DOF flexible joint robots

A new impedance controller based on the dynamic surface control-backstepping technique to actualize the anticipant dynamic relationship between the motion of end-effector and the external torques was presented. Comparing with the traditional backstepping method that has ＂explosion of terms＂ problem, the new proposed control system is a combination of the dynamic surface control technique and the backstepping. The dynamic surface control （DSC） technique can resolve the ＂explosion of terms＂ problem that is caused by differential coefficient calculation in the model, and the problem can bring a complexity that will cause the backstepping method hardly to be applied to the practical application, especially to the multi-joint robot. Finally, the validity of the method was proved in the laboratory environment that was set up on the 5-DOF （degree of freedom） flexible joint robot. Tracking errors of DSC-backstepping impedance control that were 2.0 and 1.5 mm are better than those of backstepping impedance control which were 3.5 and 2.5 mm in directions X, Y in free space, respectively. And the anticipant Cartesian impedance behavior and compliant behavior were nchieved successfully as depicted theoretically.

Stability Monitoring and Control of Generation Based on the Synchronized Measurements in Nodes of Its Connection

Synchronized distributed measurements of mode parameters create a technical feasibility for development and implementing new technologies of control the mode stability and the admissibility of EPS （electric power system） mode. Discussion will focus on different models obtained from data synchronized measurements for operational and automatic emergency control without EPS being totally controlled. According to the proposed technology, the generator＇s output power restrictions are determined in real-time by the terms a static stability using the generators＇ mode model as a multipole with connection nodes of generators＇ electromotive forces （the matrix of SMA （self and mutual admittances） of electromotive forces of generators）. Potential applications of the technology are distribution network with the main substation and generators of commensurable capacity, and transmission network with large power plants （generators） distributed into the network. The one-level control system for all of generators with defining the generator＇s power limits relative to the main substation is implemented in the first case. In the second case, the two-level control system is brought in, based on the separation of large and small generation motion. The results of the method and technology efficiency verification are shown in the paper, by both computer simulations of the power system modes and its physical model.

Using a Computer Driven PID Regulator for Controlling the Vacuum Pump of a Mechanical Milking Machine

Conventional vacuum control in a milking system is accomplished by using a vacuum pump, sized for the maximum air flows into the milking system, running at a full speed. The difference between the pump capacity and the necessary flow of air is compensated by allowing air to enter the system through a regulator. The solution presented in this paper uses a VFD （variable frequency driver） in order to drive the vacuum pump at a controlled speed, so that the air removed equals the air entering the milking system. The VFD technology is able to adjust the rate of air removal from the milking system, by changing the speed of the vacuum pump motor. The VFD is controlled by a computer using a virtual instrument in order to emulate a PID （proportion integration differentiation） regulator. The tests aimed to evaluate the vacuum regulator characteristics and vacuum stability. A statistical analysis of the experimental results was performed and it showed that there was a significant difference between the experimental results obtained for the two methods of vacuum regulation （with vacuum regulator and VFD controller respectively）. The experimental results proved that the used of the VFD controller led to a higher vacuum stability in terms of the error between the set vacuum value and the achieved values.

Energy-Saving Design for Hydraulic Tube Bender

Generally speaking, hydraulic control systems can be divided into two different driving concepts. The first one is the well-known hydraulic valve-controlled system and the second one is the pump-controlled system. The former possesses the feature of fast dynamic response. However, the poor energy-saving performance is its major fault. On the contrary, the hydraulic pump-controlled system has the significant advantage of energy-saving which meets the current demand in modem machine design. In this paper, the simulation analysis using MatLab/SimuLink and DSHplus software for a newly developed energy-saving hydraulic tube bender is conducted. Instead of the conventional fixed displacement hydraulic pump, the new hydraulic tube bender utilizes an internal gear pump with AC servomotor as its driving power source. In the new energy-saving hydraulic circuit, the use of conventional pressure relief valve and unloading valve are no longer necessary since the demanded flow-rate and pressure output can be precisely obtained by continuously changing the speed of the AC servomotor. In addition, two closed-loop control schemes using fuzzy sliding-mode controller are adopted and compared. To compare the energy-saving control systems, such as load-sensing control system, constant supply pressure control scheme and conventional hydraulic control scheme. Furthermore, the simulation results also show that the newly developed hydraulic tube bender can save up to 43% of energy consumption in a working cycle as compared to the conventional hydraulic tube bender.

Frequency Regulation of Alternating Current Microgrid Based on Hierarchical Control Using Fuzzy Logic

An alternating current(AC)microgrid is a system that integrates renewable power,power converters,controllers and loads.Hierarchical control can manage the frequency of the microgrid to prevent imbalance and collapse of the system.The existing frequency control methods use traditional proportion integration(PI)controllers,which cannot adjust PI parameters in real-time to respond to the status changes of the system.Hierarchical control driven by fuzzy logic allows real-time adjustment of the PI parameters and the method used a two-layer control structure.The primary control used droop control to adjust power distribution,and fuzzy logic was used in the voltage loop of the primary control.The secondary control was added to make up for frequency deviation caused by droop control,and fuzzy logic was used in the secondary frequency control to deal with the dynamic change of frequency caused by the disturbances of loads.The proposed method was simulated in Matlab/Simulink.In the primary control,the proposed method reduced the total harmonic distortion(THD)of two cycles of the output voltage from 4.19%to 3.89%;in the secondary control,the proposed method reduced the frequency fluctuation of the system by about 0.03 Hz and 0.04 Hz when the load was increased and decreased,respectively.The results show that the proposed methods have a better effect on frequency maintenance and voltage control of the AC microgrid.

Steering control for underwater gliders

Steering control for an autonomous underwater glider （AUG） is very challenging due to its changing dynamic char- acteristics such as payload and shape. A good choice to solve this problem is online system identification via in-field trials to capture current dynamic characteristics for control law reconfiguration. Hence, an online polynomial estimator is designed to update the yaw dynamic model of the AUG, and an adaptive model predictive control （MPC） controller is used to calculate the optimal control command based on updated estimated parameters. The MPC controller uses a quadratic program （QP） to compute the optimal control command based on a user-defined cost function. The cost function has two terms, focusing on output reference tracking and move suppression of input, respectively. Move-suppression performance can, at some level, represent energy-saving performance of the MPC controller. Users can balance these two competitive control performances by tuning weights. We have compared the control performance using the second-order polynomial model to that using the filth-order polynomial model, and found that the tbrmer cannot capture the main characteristics of yaw dynamics and may result in vibration during the flight. Both processor-in-loop （PIL） simulations and in-lake tests are presented to validate our steering control performance.

Attractor landscape analysis of the cardiac signaling network reveals mechanism-based therapeutic strategies for heart failure

Apoptosis and hypertrophy of cardiomyocytes are the primary causes of heart failure （HF）, a global leading cause of death, and are regulated through the complicated intracellular signaling network, limiting the development of effective treatments due to its complexity. To identify effective therapeutic strategies for HF at a system level, we develop a large-scale comprehensive mathematical model of the cardiac signaling network by integrating all available experimental evidence. Attractor landscape analysis of the network model identifies distinct sets of control nodes that effectively suppress apoptosis and hypertrophy of cardiomyocytes under ischemic or pressure overload-induced HF, the two major types of HF. Intriguingly, our system-level analysis suggests that intervention of these control nodes may increase the efficacy of clinical drugs for HF and, of most importance, different combinations of control nodes are suggested as potentially effective candidate drug targets depending on the types of HF. Our study provides a systematic way of developing mechanism-based therapeutic strategies for HF.