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The automatic control device is a critical component of absorption refrigeration systems. Its functional enhancement can reduce operating costs, improve energy efficiency, and ensure long-term stable unit operation. Given that absorption refrigeration systems operate under various dynamic conditions, the rational design of control strategies is particularly important. This study analyzes the influence of changes in the cooling water and heat source water flow rates on the outlet temperature of chilled water in the unit based on the open-loop response characteristics of absorption refrigeration systems. It proposes a dual-loop energy-saving control strategy for single-effect hot water lithium bromide absorption refrigeration systems based on the setpoint comprehensive optimization algorithm. Considering the multiple variables, strong coupling, large inertia, long time delay, and nonlinear characteristics of absorption refrigeration systems, as well as the difficulties in modeling these systems, this study applies a model-free adaptive control algorithm to the system's control. It derives both SISO and MIMO model-free control algorithms with time-delay components. Through simulations comparing MFAC, improved MFAC, and traditional PID control, the dual-loop energy-saving control strategy is demonstrated to effectively reduce system heat consumption by approximately 20%, decrease power consumption by about 10%, and enhance the system's SCOP by approximately 19.3%. [ABSTRACT FROM AUTHOR]

The multi-degree-of-freedom characteristics of the planetary gear electronic continuously variable transmission (ECVT) configuration in series-parallel hybrid tractors impose more complex requirements for energy management strategies under variable load conditions. For a high-power hybrid tractor, this paper takes the hybrid tractor output-split (OS)-ECVT configuration as the research object and describes the principles of stepless transmission and power-splitting within the configuration. In order to improve the fuel economy of high-power hybrid tractors and the running status of power components, an energy management strategy focused on ploughing conditions based on the Bellman minimum dynamic programming (DP) algorithm is proposed in this paper. Second, equivalent fuel consumption is selected as the performance index for energy-saving control, and the solving principle of the energy management strategy based on the dynamic programming algorithm is established to facilitate the resolution process of the energy management strategy. Finally, the energy-saving control simulation is completed under ploughing conditions. The results show that compared with the energy management strategy based on the optimal operating line (OOL), the energy management strategy based on DP fully utilizes the benefits of low-cost electric energy and enables the hybrid power system to have a wider range of stepless transmission performance. In addition, the hybrid power system has the advantages of enhanced decoupling of speed and torque, higher efficiency, and more economical secondary energy conversion. As a result, the whole machine has enhanced power-split performance, greatly improving the running conditions of the power components. The equivalent fuel consumption values of the energy management strategies based on DP and OOL are about 3.1238 L and 4.2713 L, respectively. The equivalent fuel consumption based on DP is reduced by about 26.87%, which effectively improves the fuel efficiency of hybrid tractors. [ABSTRACT FROM AUTHOR]

Objective Urban rail transit generates a considerable amount of energy consumption during operation, with traction energy consumption of train operation offering significant optimization potential. Therefore, there is an urgent need to study a train traction energy-saving control strategy. Method Firstly, a dynamic equation of train operation is established, and the constraint conditions for the train operation process are defined. Secondly, the optimization strategy for train traction energy consumption is decomposed to establish the objective function.Based on the genetic algorithm model, the allocation of train operation energy consumption in different intervals and the optimal cruising speed within intervals are solved. Then, through the cross mutation process of the genetic algorithm, the optimal energy-saving effect of the driving speed recommendation curve is obtained. Finally, a simulation model is built using Matlab software, with real-line train parameters and operational data to simulate the inter-station operation process of the train. Result & Conclusion Experimental results show that the control strategy based on the genetic algorithm model, compared to the conventional fixed working condition sequence control strategies, significantly improves traction energy-saving indicators.

Copyright of Urban Mass Transit is the property of Urban Mass Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

One of the primary contributors to automobile exhaust pollution is the significant deviation between the actual and theoretical air-fuel ratios during transient conditions, leading to a decrease in the conversion efficiency of three-way catalytic converters. Therefore, it becomes imperative to enhance fuel economy, reduce pollutant emissions, and improve the accuracy of transient control over air-fuel ratio (AFR) in order to mitigate automobile exhaust pollution. In this study, we propose a Linear Active Disturbance Rejection Control (LADRC) Hydrogen Doping Compensation Controller (HDC) to achieve precise control over the acceleration transient AFR of gasoline engines. By analyzing the dynamic effects of oil film and its impact on AFR, we establish a dynamic effect model for oil film and utilize hydrogen's exceptional auxiliary combustion characteristics as compensation for fuel loss. Comparative experimental results demonstrate that our proposed algorithm can rapidly regulate the AFR close to its ideal value under three different transient conditions while exhibiting superior anti-interference capability and effectively enhancing fuel economy.

The multi-degree-of-freedom characteristics of the planetary gear electronic continuously variable transmission (ECVT) configuration in series-parallel hybrid tractors impose more complex requirements for energy management strategies under variable load conditions. For a high-power hybrid tractor, this paper takes the hybrid tractor output-split (OS)-ECVT configuration as the research object and describes the principles of stepless transmission and power-splitting within the configuration. In order to improve the fuel economy of high-power hybrid tractors and the running status of power components, an energy management strategy focused on ploughing conditions based on the Bellman minimum dynamic programming (DP) algorithm is proposed in this paper. Second, equivalent fuel consumption is selected as the performance index for energy-saving control, and the solving principle of the energy management strategy based on the dynamic programming algorithm is established to facilitate the resolution process of the energy management strategy. Finally, the energy-saving control simulation is completed under ploughing conditions. The results show that compared with the energy management strategy based on the optimal operating line (OOL), the energy management strategy based on DP fully utilizes the benefits of low-cost electric energy and enables the hybrid power system to have a wider range of stepless transmission performance. In addition, the hybrid power system has the advantages of enhanced decoupling of speed and torque, higher efficiency, and more economical secondary energy conversion. As a result, the whole machine has enhanced power-split performance, greatly improving the running conditions of the power components. The equivalent fuel consumption values of the energy management strategies based on DP and OOL are about 3.1238 L and 4.2713 L, respectively. The equivalent fuel consumption based on DP is reduced by about 26.87%, which effectively improves the fuel efficiency of hybrid tractors.

The automatic control device is a critical component of absorption refrigeration systems. Its functional enhancement can reduce operating costs, improve energy efficiency, and ensure long-term stable unit operation. Given that absorption refrigeration systems operate under various dynamic conditions, the rational design of control strategies is particularly important. This study analyzes the influence of changes in the cooling water and heat source water flow rates on the outlet temperature of chilled water in the unit based on the open-loop response characteristics of absorption refrigeration systems. It proposes a dual-loop energy-saving control strategy for single-effect hot water lithium bromide absorption refrigeration systems based on the setpoint comprehensive optimization algorithm. Considering the multiple variables, strong coupling, large inertia, long time delay, and nonlinear characteristics of absorption refrigeration systems, as well as the difficulties in modeling these systems, this study applies a model-free adaptive control algorithm to the system’s control. It derives both SISO and MIMO model-free control algorithms with time-delay components. Through simulations comparing MFAC, improved MFAC, and traditional PID control, the dual-loop energy-saving control strategy is demonstrated to effectively reduce system heat consumption by approximately 20%, decrease power consumption by about 10%, and enhance the system’s SCOP by approximately 19.3%.

With the development of the energy control system of iron and steel enterprises, the urgency of solving the problem of the resource and energy saving control of steelmaking processes increases, taking into account the reconfiguration of production to a new task, intensification of the processes of recycling of raw materials, as well as reducing the waste intensity of production. The way to solve the problem of resource and energy saving of steelmaking production is the creation of a computer system. It allows one to analyze the state of the refractory converter lining, calculation of the material and thermal balances, the amount of slag-forming materials, the quantitative characteristics of slag corrosion, as well as predict the phase and chemical composition of the slag in order to impart the properties necessary in the production of mineral binders and other building materials. The computer system allows one to identify complex fuzzy relationships between process parameters and issue recommendations on the resource and energy saving control of the converter process, taking into account the waste recycling. The testing of the computer system, according to the industrial data of the enterprises CherMF (PJSC Severstal) and PJSC NLMF, confirmed its operability and the possibility of its use at iron and steel enterprises. [ABSTRACT FROM AUTHOR]

In this study, an energy-saving control strategy based on instantaneous optimization is proposed to improve the energy efficiency of hybrid tractors. Using a parallel diesel–electric hybrid tractor as the research object, the topological and working characteristics were analyzed, and a coupled dynamic model of rotary tillage and tractor plow was constructed. Aiming to minimize the equivalent fuel consumption of the entire machine, the motor and diesel engine torques were taken as the control variables, and the state of charge of the power battery was taken as the state variable. Subsequently, an energy-saving control strategy based on instantaneous optimization is proposed. Finally, a simulation experiment was carried out using MATLAB to verify the effectiveness of the energy-saving control strategy based on instantaneous optimization. Compared with the energy-saving control strategy based on power-following, the results show that energy-saving control strategy based on instantaneous optimization can reasonably control the operating state of the diesel engine and motor. Therefore, the diesel engine and motor work in the high-efficiency area, and effectively reduce the equivalent fuel consumption of the tractor during field operation. Under rotary tillage and plowing conditions, equivalent fuel consumption is reduced by 4.70% and 6.31%, respectively. [ABSTRACT FROM AUTHOR]

Energy-saving techniques are critical for the low-carbon design of equipment. Focusing on global energy efficiency during operation, a powertrain with multidimensional controllable variables (MCVP) is developed to reduce the installed power and energy consumption of mechanical-electro-hydraulic equipment working under various conditions. By altering the combination of controllable variables, the output characteristics of the powertrain can be adjusted to match the demands of various working conditions. This approach fundamentally and comprehensively addresses the issues of overflow losses and low energy conversion efficiency in equipment. To realize the energy-saving potential of the powertrain, an optimized design method is presented to improve the degree of matching between the load and the powertrain. A dual-layer energy-saving control strategy is proposed for high energy efficiency and tracking accuracy. The first layer is the energy-saving strategy which is executed to find the optimal combination of the controllable variables. The second layer is a controller which is employed to ensure tracking accuracy. Three case studies are analyzed to validate the effectiveness of the powertrain and the control strategy. The installed power and total energy consumption are reduced by 41.7% and 26.9% for a large-ton hydraulic press, respectively. Then, the energy-saving ratio is up to 18.5% for a small-ton hydraulic press. A mechanical powertrain has 26.6% and 17.2% reduction ratios of the installed power and the energy consumption, respectively. Finally, the control performance meets the requirements based on the designed controllers. Furthermore, the extension concept and more specific configurations of the MCVP are discussed for broader applications. • Developing a powertrain with wide application potential for energy savings. • Demonstrating an energy-efficient load domain based design method. • A dual-layer control strategy is proposed for energy savings and tracking accuracy. • Three applications are presented to validate the effectiveness of the powertrain. • More specific configurations of the powertrain are discussed for broad feasibility. [ABSTRACT FROM AUTHOR]

To achieve energy-saving control of non-hybrid Hydrostatic Transmission Construction Vehicles (HST-CVs) with traditional closed-loop Hydrostatic Transmission (HST) for both propulsion and working systems, this paper presents a control strategy for non-hybrid HST-CVs by referring to the power follower method of the hybrid Energy Management Strategy (EMS). Through the implementation of the presented control strategy by coordinated control of the engine speed and hydraulic pump displacement, the engine can be controlled to operate at the pre-set low Brake Specific Fuel Consumption (BSFC) area, similar to that of the hybrid vehicles adopting a power follower control strategy but without the additional installation of accumulators in the hydraulic system. The effect of the control strategy is verified via experimental tests and MATLAB/SIMULINK–AMESIM COLlaborative SIMulation (COSIM). The simulation results show that the proposed control strategy can achieve the expected control target under both highway and off-road conditions.

Manufacturers are pursuing energy-efficient production in response to the fluctuating energy price, growing global competition, rigorous international laws, and severe environmental crisis. This article proposes to boost the energy efficiency of production systems by controlling the production. It extends the existing energy-saving control research by presenting integrated modeling, analyzing, and controlling approaches. The work starts from the modeling of the production systems and establishes an analytical model to systematically quantify the production loss resulted from energy-saving control and the various disruptions. A dynamic control algorithm is proposed to reduce energy consumption and maintain desirable productivity. Simulation studies are utilized to demonstrate the application of the proposed method and verify its effectiveness. Note to Practitioners—The previous research indicates that it is possible to strategically turn off stations during production for energy saving. However, production systems are complex dynamic systems consisting of interconnected stations and supporting subsystems. Similar to station random failures, turning off stations for energy saving can severely jeopardize the production, and deviate the production from the desired target. Therefore, a quantitative method is established to calculate the production loss resulted from the energy-saving control and disruptions. The method is important to understand the real control cost. Based on the analysis, a dynamic control algorithm is formulated to balance the achieved control benefit and the production loss. It provides plant managers a useful tool to make energy-saving control decisions with a thorough understanding of production system dynamics. The presented research is established for serial batch production systems. The examples of batch stations include the refrigerator foaming equipment in refrigerator assembly lines and the vacuum oven in battery assembly lines. The model cannot be directly applied in serial-parallel production systems. [ABSTRACT FROM AUTHOR]

In this study, we developed a group of multipoint user location sensing fans to achieve an energy-saving control system. In general, a fan has functions of cooling and exhausting, depending on the use scenario. The proposed system employs the wireless signal strength of a user's mobile device to control the fan speed by multipoint position sensing. The signal strength is suitable for use as a control parameter to allow the wind speed to be stabilized to achieve a comfortable environment, and the results of the calculation of the fan group energy efficiency control algorithm based on the multipoint location information established in this paper are compared with the actual measured values validated to achieve an energy-efficient fan control system. [ABSTRACT FROM AUTHOR]

In this article, in order to improve the power quality and decrease the consumed power of an induction motor (IM), which is supplied by an alternate battery-powered system, an algorithm that can be used to save its energy consumption has been proposed. The control mechanism is used to reduce the wasted energy caused by IMs start-up current based on bounding its optimal starting voltage. The proposed algorithm includes two parts: First, use branch-and-bound theory to derive the control rule of the IMs start voltage and give corresponding offline calculation procedure framework. Second, according to the control rule, adjust online voltage of the zinc–bromine flow battery, which is used to feed the IM. Due to the proposed approach, the minimum start-up voltage of the battery-powered system can be predicted and by which one the IMs surge current has been suppressed online. Moreover, the relationship of the output voltage of the battery and inverter supply to the load current has been derived by modeling the battery-powered system. The experiments demonstrate that compared with before optimization, the amount of energy consumption of the IM supplied by zinc–bromine flow battery decreases by 8.5% and corresponding indicator parameters of the power quality can reach the standard IEC TS62749-2015. [ABSTRACT FROM AUTHOR]

In order to improve the energy-saving level of commercial buildings' air-conditioning units with double cold sources and reduce the energy cost, an energy-saving optimal control method of commercial buildings' air-conditioning units with double cold sources based on self-organizing neural network is proposed. Constrained parameter model of energy-saving control of commercial buildings' double-cold-source air-conditioning units is constructed. Taking the balanced real-time dynamic adjustment characteristic quantity of inverter of commercial buildings' double-cold-source air-conditioning units as the control object, combined with the fuzzy constraint method of variable frequency speed adjustment parameters and stroke adjustment power of commercial buildings' double-coldsource air-conditioning units, the steady-state adjustment of energy-saving output of commercial buildings' double-cold-source air-conditioning units is realized, and the self-organizing neural network control model of periodic potential energy load of building HVAC system is established. Combined with the small disturbance suppression method of motor rated power, the optimal control design of energy-saving of commercial buildings. The simulation results show that the output stability of the energy-saving control of commercial building air-conditioning units with double cold sources is good, the steady-state working ability is strong, and the energy-saving effect of commercial building air-conditioning units with double cold sources is good. [ABSTRACT FROM AUTHOR]

• Proposes a multi-stage determination method for excavator working points that considers engine fuel consumption, hydraulic pump efficiency, and load fluctuation, overcoming limitations of traditional methods. • Introduces a comprehensive evaluation model for working point determination that integrates fuel consumption, hydraulic pump efficiency, and load variability, offering a more holistic approach. • Utilizes experimental data to inform the determination of engine working points, ensuring practical relevance and applicability. • Employs weight parameters to adjust the importance of fuel consumption and load fluctuation in the working point optimization process, allowing for tailored engine performance improvement under varying operational needs. In view of the problem that the traditional working point determination method only considers the engine fuel consumption and does not consider the hydraulic pump efficiency and load fluctuation in the process of the working point stability control of an excavator engine, a simple and feasible, experimental data-driven, multi-stage determination method of excavator working point based on the comprehensive evaluation model is proposed. In this paper, the comprehensive evaluation model of working point torque with weight parameters is established at different working stages under the rated speed in a phased way. The results show that this method can determine the working point torque at different working stages, and reduce engine fuel consumption and load fluctuation based on ensuring the efficiency of the hydraulic pump. The lowest engine fuel consumption can be reduced by 7.09%, and the lowest load fluctuation can be reduced by 17.8%. In addition, by modifying the weight parameters, we can emphasize the fuel consumption and load fluctuation of the engine according to their importance, to achieve the determination of working points under different requirements. This approach also provides a new idea for optimizing the working point of construction machinery. [ABSTRACT FROM AUTHOR]

To allow the hoisting motor drive system of a crane to track a load torque quickly, a linearization method was used to transform a motor nominal dynamics model into two decoupled linear rotor speed and flux linkage subsystems. The method based on the theory of differential geometry was a precise feedback method. Two active disturbance rejection controllers (ADRCs) with identical structures were designed for the rotor speed and flux linkage subsystems. The extended state observer of the ADRC could estimate the unmodeled dynamics of the motor, the variation of motor parameters due to heating, and the unknown disturbances of the motor system to determine the total disturbances of the system. A closed-loop system with ADRC and an open-loop system were compared. The motor’s full-load starting time was reduced by about 50%. When the motor operated smoothly at different load rates and the rated load was suddenly applied, the electromagnetic torque fluctuation range did not exceed $20~\text {N}\cdot \text {m}$ . The rotor flux was always stable at the reference value. The motor speed decreased, but the amount of decrease did not exceed 7 rad/s. The closed-loop system had a significant energy-saving effect during the motor’s starting process. The power saving rate was about 55%–59% if the motor started with a light load. The power saving rate could reach 71% if the motor started with a heavy load. The ADRC system could accurately estimate the unknown model of the rotor speed and flux linkage subsystems, and adapt to parameter variations of the motor stator and rotor resistance in the range of ±10%.

Generally, during the accelerating process of construction machinery large inertia hydraulic swing system, a lot of kinetic energy is accumulated, and it will be eventually dissipated through the relief valve orifice during the decelerating process, which results in serious energy waste and large overflow loss. In order to solve this problem, a new dual source hydraulic motor with non-uniform flow distribution is proposed, which can drive high-frequency swing mechanism efficiently. The new dual source hydraulic motor has two groups of oil inlet and outlet, corresponding to two groups of different displacement. The two groups of inlet and outlet are respectively connected with the energy recovery unit and the main driving unit. During the starting process, the energy recovery unit assists the main driving unit to drive the swing mechanism together, so that the main drive unit output torque and overflow loss are reduced; during the braking process, the energy recovery unit recovers the braking energy. Finally, the integrated control of braking energy direct recovery and utilization is realized. In the research, the 38 t hydraulic excavator is taken as the research object. Firstly, the multi-body dynamics electro-hydraulic simulation model of the dual source integrated driving hydraulic excavator swing system is established, and the accuracy of the model is verified by experiments. Then the effects of the accumulator working pressure and the dual source hydraulic motor displacement ratio on the working performance of the system were simulated. The simulation results show that with the displacement ratio increasing, the accelerating time, the maximum angular velocity and decelerating time increase. Compared with the original system, when the displacement ratio $\alpha $ is 0.6, the comprehensive performance of the system is the best, and the hydraulic pump output energy is reduced by 48.6% and 46.6% respectively in the process of full load and no-load operation.

In this study, an energy-saving control strategy based on instantaneous optimization is proposed to improve the energy efficiency of hybrid tractors. Using a parallel diesel–electric hybrid tractor as the research object, the topological and working characteristics were analyzed, and a coupled dynamic model of rotary tillage and tractor plow was constructed. Aiming to minimize the equivalent fuel consumption of the entire machine, the motor and diesel engine torques were taken as the control variables, and the state of charge of the power battery was taken as the state variable. Subsequently, an energy-saving control strategy based on instantaneous optimization is proposed. Finally, a simulation experiment was carried out using MATLAB to verify the effectiveness of the energy-saving control strategy based on instantaneous optimization. Compared with the energy-saving control strategy based on power-following, the results show that energy-saving control strategy based on instantaneous optimization can reasonably control the operating state of the diesel engine and motor. Therefore, the diesel engine and motor work in the high-efficiency area, and effectively reduce the equivalent fuel consumption of the tractor during field operation. Under rotary tillage and plowing conditions, equivalent fuel consumption is reduced by 4.70% and 6.31%, respectively.

With the development of the energy control system of iron and steel enterprises, the urgency of solving the problem of the resource and energy saving control of steelmaking processes increases, taking into account the reconfiguration of production to a new task, intensification of the processes of recycling of raw materials, as well as reducing the waste intensity of production. The way to solve the problem of resource and energy saving of steelmaking production is the creation of a computer system. It allows one to analyze the state of the refractory converter lining, calculation of the material and thermal balances, the amount of slag-forming materials, the quantitative characteristics of slag corrosion, as well as predict the phase and chemical composition of the slag in order to impart the properties necessary in the production of mineral binders and other building materials. The computer system allows one to identify complex fuzzy relationships between process parameters and issue recommendations on the resource and energy saving control of the converter process, taking into account the waste recycling. The testing of the computer system, according to the industrial data of the enterprises CherMF (PJSC Severstal) and PJSC NLMF, confirmed its operability and the possibility of its use at iron and steel enterprises.

One of the primary contributors to automobile exhaust pollution is the significant deviation between the actual and theoretical air-fuel ratios during transient conditions, leading to a decrease in the conversion efficiency of three-way catalytic converters. Therefore, it becomes imperative to enhance fuel economy, reduce pollutant emissions, and improve the accuracy of transient control over air-fuel ratio (AFR) in order to mitigate automobile exhaust pollution. In this study, we propose a Linear Active Disturbance Rejection Control (LADRC) Hydrogen Doping Compensation Controller (HDC) to achieve precise control over the acceleration transient AFR of gasoline engines. By analyzing the dynamic effects of oil film and its impact on AFR, we establish a dynamic effect model for oil film and utilize hydrogen's exceptional auxiliary combustion characteristics as compensation for fuel loss. Comparative experimental results demonstrate that our proposed algorithm can rapidly regulate the AFR close to its ideal value under three different transient conditions while exhibiting superior anti-interference capability and effectively enhancing fuel economy., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Yingjie Zhang reports financial support was provided by National Natural Science Foundation of China. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Frequency conversion exchanger control is the critical technology of solar water heaters. It can integrate solar thermal technology and heat pump technology and makes solar thermal energy conversion efficiency higher. Based on this research background, the paper first discusses the principle of the technology. Then, it optimizes the system control strategy based on maximizing the utilization of heat energy and the highest efficiency ratio. Finally, the article established a deep learning model of solar radiation based on different time-sharing. The experimental simulation confirmed that the thermal energy control optimization algorithm model proposed in this paper could effectively predict thermal energy exchange. [ABSTRACT FROM AUTHOR]

In order to reduce energy consumption of machine tools in waiting processes, a energy-saving control decision-making method for CNC machine tools was proposed based on transfer learning. By analyzing energy-saving control condemns of machine tools, 5 energy-saving control strategies of the machine tools in waiting processes were proposed. Considering diversity and complexity of production data, an energy-saving decision-making method was established based on deep belief networks and transfer learning. Through analyzing a case of elevator part manufacturing workshops, it is found that energy saving decision errors of this method are as 3.2%, and the total energy consumption in machine tools waking processes is reduced by 52.5%. [ABSTRACT FROM AUTHOR]

For problems of high energy consumption of belt conveyor and inability to adjust control automatically according to actual coal quantity, a coal mine belt conveyor control system based on load detection was designed. Overall load and material distribution of belt conveyor are obtained in real time through load detection device. Running speed of belt conveyor is automatically controlled according to the overall load, and start-up along coal flow of multi-level series belt conveyor is realized according to material distribution. The application result shows that the system realizes less human operation management of belt conveyor, reduces energy consumption and improves transportation efficiency.

Copyright of Scientific Bulletin of National Mining University is the property of National Mining University, State Higher Educational Institution and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• The radar information is utilized to improve the energy efficiency of vehicle. • The objectives of energy efficiency, driving intention and safety are considered. • The strategy is verified by real vehicle experiment under actual traffic condition. In the existing driver assistance systems of electric vehicle, the vehicular forward radar is mainly used for active safety control and seldom for energy-saving control. In order to improve the energy efficiency of electric vehicle, this paper proposes a novel energy-saving control strategy for electric vehicle based on movement of the preceding vehicle detected by forward radar. A hierarchical control architecture, which consists of three layers, is adopted in the proposed strategy. In the upper layer, the vehicles' relative motion state is classified into four different scenarios based on the assessment of driving safety. In the middle layer, the energy-saving mode decision and transition control strategy are designed according to the scenario classification. In the bottom layer, the motor's torque optimization and coordination control strategy are proposed to improve energy efficiency, while ensuring both driving safety and ride comfort. An optimized control algorithm based on Model Predictive Control (MPC) theory, is designed to optimize the motor's torque for each mode in real-time. Finally, our proposed energy-saving control strategy is applied to an electric bus. Simulation and experiment tests are carried out to verify the effectiveness of the designed energy-saving control strategy. The results show that the proposed strategy can significantly reduce the energy consumption of electric vehicle under urban road conditions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effect of temperature on high accuracy measurements is well known, and temperature controlled environments are a must for metrology of high accuracy mechanical parts. It is therefore not surprising that temperature would play an important role in controlling actuators capable of achieving nanometer resolutions. In most cases the thermal expansion of the components is the main issue with changes with temperature, but in the case of ferromagnetic shape memory alloys (FSMA) based actuators, there are additional complications. First, the material is highly hysteric and when actuated it rapidly self-heats the material. Secondly, the phase transition of the NiMnGa alloy used in the actuator is centered at about 330 K, and at this temperature the performance of the material starts to degrade because it starts to transform into the magnetically inactive cubic phase. In this work we analyze an actuator that uses orthogonal magnetic fields to deform the crystal under no external load. The actuator's control system operates in a “set-and-forget” mode, following an event-based control scheme and is able to achieve a position with a given precision and transient behavior, needing a reduced number of control actions and, then, a reduced energy consumption. In addition, the paper discusses the control implications of the temperature dependency of the actuator's behavior, based on experimental results. [ABSTRACT FROM AUTHOR]

Copyright of Computer Measurement & Control is the property of Magazine Agency of Computer Measurement & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two different strategies are presented for the control of a positioning actuator based on a ferromagnetic shape memory alloy (FSMA). The actuator consists of two orthogonal pairs of coils that generate a pulsed magnetic field when a bank of capacitors is discharged through one of the coil pairs. The FSMA element is located between the coils and expands when a field perpendicular to the crystal's long axis is applied, and contracts in response to a parallel one. In each case, the deformation of the element remains until a driving force in the opposite direction is applied, therefore operating in a “set-and-forget” mode. The current experimental set-up is capable of achieving submicrometer resolutions. Two discrete control strategies are proposed and compared based on their ability to achieve a position with a given precision and transient behaviour. Taking into account that the energy consumption of the actuator is directly related to the number of control actions, two control strategies aimed to minimize such consumption by reducing the number of actions are presented and their experimental performance described. The first of the proposed strategies has two control modules, one for each pair of coils, while the second approach is based on an event-based PI control algorithm. [ABSTRACT FROM AUTHOR]

The elevator group is scheduled by suitable algorithm according to different traffic mode, and the performance of the elevator group control system will be improved. The kernel fuzzy clustering (KFCM) algorithm based on particle swarm optimization (PSO) is proposed to identify the elevator traffic mode. The iterative process based on gradient descent in KFCM algorithm is replaced by PSO algorithm, which has stronger global search capability and local search capability. Meanwhile the sensitivity to initial value of the FCM algorithm is decreased. By using kernel method, the sample in the low-dimensional feature space is mapped into high-dimensional feature space. And the sample feature is optimized and can be linearly divided in high-dimensional feature space so that clustering could be performed efficiently. The elevator traffic flow data collected from some office building is regard as the test sample. The simulation results show that the algorithm proposed has better performance indices compared with FCM algorithm, and the clustering effect of elevator traffic flow is more exact. [ABSTRACT FROM AUTHOR]

Abstract: On the guarantee of the effluent quality, the pursuing of the shortest operation time, that is the best capacity, is the purpose of the existing control law of the SBR. In this essay, another valuable control law for the aim of energy saving when time is not so important was advanced. By the comparison of these two control laws, it is proved that the latter was obviously effective on the energy saving. [Copyright &y& Elsevier]

n approach is described for estimating the pump's variables based only on measuring the motor's electrical variables. The method is based on extended Kalman filter estimation of the pump's shaft power and velocity and on-line calculation of the head and flow rate using steady-state pump curves. The application of the method for the head and flow-rate stabilization systems is demonstrated in simulations. [ABSTRACT FROM AUTHOR]

[Display omitted] • Description of the nonsaturation effect in the FSMA actuator due to the pulsed nature of the actuation. Contrarily to other FSMA actuators, the actuator's position increases when the same input voltage is applied until a saturation point is reached. • A numerical optimization procedure is proposed for automating the control design process. The manual control design is complex due to the actuator characteristics and the advanced control implemented. • The optimization process uses an actuator model, which is obtained by mean of a machine learning technique, using Tensorflow/Keras, to overcome all the dynamic characteristics of the system. • The experimental results show that the proposed procedure is valid for obtaining accurate results for an exigent design process. This good result is specially satisfactory considering the nonlinear characteristics of the actuator and the EBC controller tuning. • The optimization procedure can be applied to other kind of actuators. Ferromagnetic shape memory alloys (FSMA) based actuators are able to get very good precision, allowing, indeed, under nanometer positioning applications. To get those precisions, a good controller is needed, and different strategies have been developed. Experimental tests with a FSMA actuator designed by the research group have proven that the use of a controller operating in a "set-and-forget"mode and following an event-based control scheme allows for a position with a given precision and transient behavior to be achieved, with a reduced number of control actions and therefore a reduced energy consumption. However, the tuning of all control parameter can be hard, especially when taking into account the nonlinear characteristics of the actuator. It can be remarked that the NiMnGa alloy used in the actuator is highly hysteric, and that the control action is pulsed. In this work, a numerical optimization based design methodology is proposed, making easier the control design procedure. The tuning procedure use a model, that for the particular actuator considered in this work, is obtained using machine learning tools, in particular the Tensorflow/Keras framework. An application example shows the good results obtained, including experimental result. [ABSTRACT FROM AUTHOR]

The objective of this research is to implement a novel parallel control of clamping force and energy-saving in hydraulic injection moulding machines (HIMMs) in order to simultaneously achieve accurate force control response and high energy efficiency. In order to verify the feasibility of the integrated control system and compare energy-saving effects, the clamping force control of HIMMs can be integrated with two different energy-saving control systems or integrated with a conventional hydraulic system without energy-saving control. The overall control system is a coupled two-input two-output system. Therefore, a decoupling fuzzy sliding-mode control (DFSMC) strategy, which can reduce the fuzzy rule numbers and counteract the coupling effects, is developed for the integrated control of HIMMs. The experimental results show the outstanding performance of the parallel control in HIMMs with DFSMC . [ABSTRACT FROM AUTHOR]

A high servo control response and a high energy efficiency, which are difficult to achieve simultaneously, are requested in hydraulic servo systems of current hydraulic injection moulding machines. This investigation develops new solutions to concurrently implement energy-saving control and velocity control for simultaneously realising high velocity control response and high energy efficiency for injection moulding machines. Two different hydraulic pump systems, including a variable displacement pump and a variable rotational speed pump, are developed and in each one of them two different energy-saving control concepts, such as load-sensing control and constant supply pressure control, are implemented. Thus, for verifying the feasibility of the integrated control systems and comparing the energy-saving effects, velocity control of the hydraulic cylinder can be integrated with four different energy-saving control systems (ESCSs) and also the conventional hydraulic system without energy-saving control. A fuzzy sliding mode control that can simplify the complex fuzzy rule bases is used for solving the complex two-input two-output systems. The experimental results show the excellent performance of the integrated concurrent control systems. [ABSTRACT FROM AUTHOR]

• Propose design method of dc contactor considering multiple influence factors. • Propose an energy-saving control strategy for dc contactor. • A prototype of 600 A/750 V dc contactor is manufactured according to the optimized parameters. In order to meet the requirement of electric vehicle to the high power direct current (dc) contactor, this paper investigates the structural optimization design method of actuator and proposes a novel energy-saving control strategy. The operating principles and structural design processes of electromagnetic actuator are demonstrated in detail. The influences of the electromagnetic parameters including the coil skeleton, the wire diameter and the spring pre-pressure are compared and analyzed and then optimized to obtain the optimal combination by orthogonal test method. A new energy-saving control strategy is proposed by adopting pulse width modulation technology to control the holding current at a smaller value after the movable iron reaches to the closed position. A co-simulation coupling magnetic field, machinery and circuit is carried out with the Maxwell and Circuit Editor software. A prototype of 600 A/750 V dc contactor is manufactured according to the optimized parameters. The experimental results validate the effectiveness of the structural optimization design method and the proposed energy-saving control strategy. [ABSTRACT FROM AUTHOR]