基于可信分析的太阳能中央热水系统的热水储量控制算法

太阳能中央热水系统的安全储水库存量对平衡用户需求及能源消耗具有重要作用,设计并建立良好安全储水库存的规划模型能有效节约太阳能中央热水系统的辅助热源耗能量. 可信性理论近来已经广泛应用于解决不确定性工程、产品管理、库存管理、电力系统模糊设计等. 分析太阳能中央热水工程运行中的各种热损耗参素,结合可信性理论,设计符合太阳能中央热水工程的安全储水库存模型,并将模型优化结果应用于太阳能中央热水系统的现场控制系统,运行数据表明该模型所得的最优解能够减少辅助热源能耗,提高能源利用率.     

Vehicle adaptive cruise control design with optimal switching between throttle and brake

For vehicle adaptive cruise control(ACC) systems,the switching performance between throttle and brake determines the driving comfort,fuel consumption and service lives of vehicle mechanical components.In this paper,an ACC algorithm with the optimal switching control between throttle and brake is designed in model predictive control (MPC) framework.By introducing the binary integer variables,the dynamics of throttle and brake are integrated in one model expression for the controller design.Then the ACC algorithm is designed to satisfy not only safe car following,but also the optimal switching between throttle and brake,which leads to an online mixed integer quadratic programming solved by the nested two-loop method.The simulation results show that the proposed ACC algorithm meets the requirements of safe car following,outperforms the traditional algorithms by performing smoother responses,reducing the switching times between throttle and brake,and therefore improves driving comfort and fuel efficiency significantly.     

Effects of heated seats in vehicles on thermal comfort during the initial warm-up period

Eight subjects participated in a subjective experiment of eight conditions to investigate the effects of heated seats in vehicles on skin temperature, thermal sensation and thermal comfort during the initial warm-up period. The experimental conditions were designed as a combination of air temperature in the test room (5, 10, 15, or 20 °C) and heated seat (on/off). The heated seat was effective for improving thermal comfort during the initial warm-up period when air temperature was lower than 15 °C. Use of heated seats prevented decreases in or increased toe skin temperature. Heated seats also increased foot thermal sensation at 15 and 20 °C. Optimal thermal sensation in contact with the seat was higher when air temperature was lower. Optimal skin temperature in contact with the seat back was higher than that with the seat cushion. Moreover, these optimal skin temperatures were higher when air temperature was lower.     

Diagnostic analysis of a small-scale incinerator by the Garson index

The formation of PCDD/Fs (dioxins/furans) due to incomplete combustion in solid waste incinerators has caused tremendous public concern. Consequently, more stringent standards for combustion and emission control have been implemented in order to mitigate the formation of these substances. This change in regulations will inevitably result in shutting down many small-scale incinerators because of the expense incurred in retrofitting such systems. Yet there is still an acute need for building small-scale incinerators for the purposes of disease control, environmental sanitation, and financial savings in rural areas and remote communities. For this reason, it is still worthwhile to pursue an optimal management strategy for small-scale incinerators. Through using the Garson index derived by a neural networks model, we can identify which operating factor is the one most influential to combustion status. Research findings clearly indicate that supplementing the auxiliary fuel via an on/off control unit is not an ideal method of maintaining a stable combustion evidenced by its relatively lower Garson index. Therefore the control of the auxiliary fuel system must be properly upgraded in order to improve its handling of the combustion unit. The results also show that the amount of waste in batch-charging and the lowest temperature of the primary chamber during the previous feeding are critical operating factors in this type of incinerator; controlling the charging amount per each feed around 30 kg is optimal for mitigating the variance of combustion status in the small-scale incinerator.     

Optimization of interorbital three-dimensional transfer trajectories for stage spacecraft

Problems of three-dimensional trajectory optimization of transfers for stage spacecraft and spacecraft with auxiliary fuel tank (AFT) from the low circuit orbit of the Earth’s artificial satellite (EAS) into the geostationary orbit and optimization problems of fuel distribution in stages or tanks are solved. Control of spacecraft motion is conducted by jet engines of bounded thrust; stage engines can have different characteristics, i.e., thrust-to-weight ratio and specific thrust. The used stage or auxiliary fuel tank is detached on the passive segment. Detachment is considered to be instantaneous, if the spacecraft position and velocity do not change at the detachment instant and the mass decreases in jumping mode. The mass of detached tanks is considered proportionate to the mass of consumed fuel; the mass of engine and auxiliary constructions, to thrust-to-weight ratio. The useful mass of the spacecraft with the limited time of transfer is maximized. The considered problems are intricate nonlinear optimal control problems with discontinuous phase variables. They are formalized as optimal control problems by a union of dynamic systems and are solved on the basis of the corresponding principle of the maximum. In this paper, boundary-value problems of the principle of the maximum are numerically solved by the shooting method. The choice of computing schemes of the shooting method and solution to systems of nonlinear equations is conducted by using a series of auxiliary problems.     

Optimizing Flight Trajectories for Space Vehicles with an Additional Fuel Tank. II

We solve the optimization problem for space trajectories of spacecraft flights with an auxiliary fuel tank from a low round orbit of a man-made Earth satellite to a geotransitional orbit. Control over the spacecraft motion is performed with a jet engine of bounded thrust. To discard the auxiliary tank, one has to turn off the engine, which takes some known time. The mass of the discarded tank is assumed to be proportional to the mass of fuel spent, and the mass of the engine and additional constructions is proportional to the thrust-to-weight ratio. We minimize the value of injection impulse needed to transfer to the geostationary orbit for a given useful mass.In the second part of the paper the problem at hand is formalized as an optimal control problem for a collection of dynamical systems and is solved based on the corresponding maximum principle. In this work we solve boundary problems of the maximum principle numerically with the shooting method. As a result of solving the problem, we construct one- and two-revolution Pontryagin extremals. We perform a series of parametric computations that are used to determine optimal parameters of the spacecraft construction: the best thrust-to-weight ratio and the best distribution of fuel among the tanks.     

太阳能热水器辅助电加热器的设计

针对目前市场上太阳能热水器辅助电加热控制系统大多存在功能单一、操作复杂、控制不便等问题。本文给出了一种基于51单片机实现的太阳能热水器辅助电加热器的设计方案。该系统以AT89S52为控制核心,AD590实现温度检测。该辅助加热器实时显示热水器的水温,自动开启加热装置等功能,具有较高的测量精度和控制精度。     

基于尖峰电价的家庭能量管理最优控制算法

智能电网技术的发展,为家庭能量管理系统(HEMS)提供了新的研究方向。针对HEMS,提出了一种基于尖峰电价的家庭用电设备最优控制算法,该方法使用层次分析法(AHP)对可调整用电设备的综合满意度进行评估,建立以满意度最高和满意度与费用最少兼顾为目标的数学模型,同时考虑家庭分布式电源及储能设备对家庭用电的影响,使用户满足电力公司在需求响应时段的约束要求并获得最满意、舒适的控制策略。最后通过案例仿真验证所提出的控制算法的实用性和有效性。     

基于二次型性能指标的混合动力汽车实时优化控制

为解决混合动力系统实时优化控制问题,本文提出了一种基于二次型性能指标最优的混合动力汽车功率分配优化方案.通过合理的假设和近似,建立了混合动力系统的线性模型,并利用二次型最优控制理论将混合动力最优控制问题转化为二次型最优调节问题进行求解,得到了一个结构简单的实时优化控制算法.5种道路工况下的仿真结果表明,本文提出的控制方法在未来道路工况未知的情况下能够实现混合动力系统的实时优化控制,且节油率与离线计算以燃油消耗最小为性能指标的全局最优控制的节油率相近.     

Digital control of a rotary dryer in the sugar industry

In order to utilize pulp, which is a by-product of the extraction of sugar from beet, one has to dry it. This is usually done with a rotary dryer. Generally the dry substance percentage of the dried pulp is controlled manually; this, however, is not sufficient. The aim was to improve the quality of control and thereby to reduce the fuel consumption. To reach this goal, first a linear, time-invariant, discrete-time mathematical model of the dynamic behaviour of the drying process was identified off-line. A correlation analysis method with least-squares parameter estimation was used. Based on the identified model, the parameters of the control algorithms of a digital multicascaded control system were designed with computer aid. The control behaviour was simulated and compared with the control behaviour achieved by an optimal state feedback control system. Although the latter one gave a better control performance, the cascaded control system was implemented on a process control computer—this was done for practical reasons. The results and experience gained during three campaigns show that the goal, a significant improvement of the control performance and the resulting saving in fuel oil, was achieved.     

基于热舒适度的办公建筑HVAC系统节能控制

建筑节能控制是一个满足舒适需求条件下的多目标优化问题,然而对于缺失运行数据的新建建筑,如何控制供暖、通风和空调(HVAC)系统达到既舒适又节能的效果是一个控制难题.针对这个问题,本文首先建立了新建建筑空间模型,然后对该模型进行能耗仿真分析,在此基础上,提出基于人员热舒适度的模糊控制算法,得出最优控制区间,从而在较低能耗水平情况下获得更长的热舒适天数,达到既节能又舒适的目标.基于人员热舒适度的节能控制对建筑HVAC系统绿色运行具有促进作用.     

基于启发式动态规划的固体氧化物燃料电池优化控制研究

固体氧化物燃料电池(SOFC)系统是一个非线性系统,现存的建模方法和优化控制算法很难对其进行精确的建模及优化控制;针对此问题,采用基于数据的建模方法,对固体氧化物燃料电池系统进行BP神经网络建模,然后在此基础上,首次采用启发式动态规划(HDP)算法对固体氧化物燃料电池系统中的各种气体分压、输出电压以及温度进行优化控制;Matlab仿真结果表明,基于BP神经网络的HDP优化算法具有收敛速度快、鲁棒性强、控制精度高等优点,并使固体氧化物燃料电池系统在负载变化时很快稳定输出电压,实现了优化控制,减少能耗。     

基于最优预见控制的高速列车速度控制器研究

针对高速列车自动驾驶(ATO)速度控制器的设计及性能问题,以列车运行过程中的安全性、舒适性、控制输入为约束条件,提出用最优预见算法设计控制器。该算法以列车动力学为基础,确定列车模型传递函数,进行极点配置之后使控制系统稳定;以列车模型为该算法的控制对象,将列车运行过程中的线路附加阻力和基本阻力作为干扰,实现列车ATO模式下目标速度的自动跟踪控制。选取京津城际北京南站至武清站间线路数据进行仿真验证,仿真结果表明该算法在降低列车运行能耗、提高旅客舒适性与列车运行准点率方面的有效性。     

考虑电枢电感的电力拖动最小能耗控制及奇异解算法的研究

大量的文献在不考虑电枢电感的条件下研究了电力拖动的最小能耗控制,其工程实现非 常困难.本文给出包括电路方程在内的最小能耗控制的数学模型.针对其中的奇异解,提出 解析数值混合算法,并运用在性能指标中引入辅助项,把奇异的最小能耗控制转化为非奇异的 最优调节器问题,从而给出了考虑电感条件下最小能耗控制的工程实现.     

电动汽车增程器燃油效率优化控制

针对如何提高增程器燃油效率,降低整车油耗的问题,提出了一种基于PRP共轭梯度法的增程器燃油效率优化控制方法.首先,以产生给定能量燃油效率最高为优化性能指标,以发动机转矩和发电机转矩为寻优变量,建立了增程器燃油效率优化控制问题的离散系统模型.然后,对算法实现过程中发动机、发电机的最高转速和最大转矩限制的处理方法进行了阐述,给出了基于PRP共轭梯度法的增程器燃油效率优化控制问题的数值实现方法的详细步骤.最后,仿真和实验结果表明本文提出的优化控制方法可以有效提高增程器的燃油效率.     

Effects of heated seat and foot heater on thermal comfort and heater energy consumption in vehicle

Subjective experiments involving 12 different conditions were conducted to investigate the effects of heated seats and foot heaters in vehicles on thermal sensation and thermal comfort. The experimental conditions involved various combinations of the operative temperature in the test room (10 or 20°C), a heated seat (on/off) and a foot heater (room operative temperature?+10 or?+20°C). The heated seat and foot heater improved the occupant's thermal sensation and comfort in cool environments. The room operative temperature at which the occupants felt a 'neutral' overall thermal sensation was decreased by about 3°C by using the heated seat or foot heater and by about 6°C when both devices were used. Moreover, the effects of these devices on vehicle heater energy consumption were investigated using simulations. As a result, it was revealed that heated seats and foot heaters can reduce the total heater energy consumption of vehicles. Statement of Relevance: Subjective experiments were conducted to investigate the effects of heated seats and foot heaters in vehicles on thermal comfort. The heated seat and foot heater improved the occupant's thermal sensation and comfort in cool environments. These devices can reduce the total heater energy consumption in vehicles.     

基于变论域模糊增量理论的质子交换膜燃料电池温度控制

质子交换膜燃料电池(PEMFC)内部的电化学反应过程直接表现为温度的变化,所以有效的温度控制是保证燃料电池可靠性和耐久性的关键.本文将模糊增量控制用于PEMFC热管理系统中,将PEMFC的温度和电堆出入口温度差保持在设定值.首先,建立PEMFC热管理系统的动态模型,包括PEMFC电堆模型和辅助散热设备模型.然后,基于建立的系统模型,设计了一种变论域的模糊增量控制器.该控制器通过伸缩因子来动态调节模糊控制器中的量化因子和比例因子,实现对模糊论域的调节,从而提高控制的灵敏性和精确度.最后,将该温度控制方法用于10 kW燃料电池系统中,实验结果表明变论域模糊增量控制器相比于其他模糊控制方法,不仅具有更快的动态响应速度,还具有更强的鲁棒性和更高的控制精度.     

Energy-efficient receding horizon trajectory planning of high-speed trains using real-time traffic information

Optimal trajectory planning of high-speed trains (HSTs) aims to obtain such speed curves that guarantee safety, punctuality, comfort and energy-saving of the train. In this paper, a new shrinking horizon model predictive control (MPC) algorithm is proposed to plan the optimal trajectories of HSTs using real-time traffic information. The nonlinear longitudinal dynamics of HSTs are used to predict the future behaviors of the train and describe variable slopes and variable speed limitations based on real-time traffic information. Then optimal trajectory planning of HSTs is formulated as the shrinking horizon optimal control problem with the consideration of safety, punctuality, comfort and energy consumption. According to the real-time position and running time of the train, the shrinking horizon is updated to ensure the recursive feasibility of the optimization problem. The optimal speed curve of the train is computed by online solving the optimization problem with the Radau Pseudo-spectral method (RPM). Simulation results demonstrate that the proposed method can satisfy the requirements of energy efficiency and punctuality of the train.     

Effects of heated seat and foot heater on thermal comfort and heater energy consumption in vehicle

Subjective experiments involving 12 different conditions were conducted to investigate the effects of heated seats and foot heaters in vehicles on thermal sensation and thermal comfort. The experimental conditions involved various combinations of the operative temperature in the test room (10 or 20°C), a heated seat (on/off) and a foot heater (room operative temperature +10 or +20°C). The heated seat and foot heater improved the occupant's thermal sensation and comfort in cool environments. The room operative temperature at which the occupants felt a ‘neutral’ overall thermal sensation was decreased by about 3°C by using the heated seat or foot heater and by about 6°C when both devices were used. Moreover, the effects of these devices on vehicle heater energy consumption were investigated using simulations. As a result, it was revealed that heated seats and foot heaters can reduce the total heater energy consumption of vehicles.

Statement of Relevance: Subjective experiments were conducted to investigate the effects of heated seats and foot heaters in vehicles on thermal comfort. The heated seat and foot heater improved the occupant's thermal sensation and comfort in cool environments. These devices can reduce the total heater energy consumption in vehicles.     

Optimal control solution of the automotive emission-constrained minimum fuel problem

The automotive industry is confronted with the conflicting goals of improving fuel economy, reducing exhaust emissions, and maintaining vehicle driveability. Difficulties arise in the application of optimal control theory to this problem because transient models of the fuel, emission and driveability responses do not exist. To circumvent these difficulties, the mathematical models are replaced by a sophisticated experimental test setup. To demonstrate the applicability of the optimal control approach without a mathematical model, the problem of the hot-start optimization of fuel economy subject to emission constraints problem is solved. Operational considerations necessitate the direct incorporation of the control functions into the gradient-type solution algorithm. The solution of this problem demonstrates the feasibility of the experimental optimal control approach. The second problem involves the cold-start portion of the Federal Test Procedure (FTP). The transient influences of the engine and catalytic converter warmup are analyzed by the optimization procedure and are reflected in the optimized control functions. Finally, the hot-start optimization program is generalized to include an explicit surge-type driveability constraints on the controls. Comparison of the results of the hot-start problems reveals the trade-off between fuel economy and driveability.