基于USB和串口通信的点火能量测试系统设计

为改善某型煤油发动机的冷启动性能,需测定发动机电感式点火系统在不同充磁时间下的点火能量,设计了一套点火能量测试系统,利用VC++开发了点火能量测试软件,实现了测试软件与数字示波器及点火控制器的通信,并进行了点火能量测试。试验结果表明,该测试系统能够准确地测试点火能量。     

Neuro-controller for reducing cyclic variation in lean combustion spark ignition engines

Literature shows that by controlling engines at extreme lean operating conditions (equivalence ratio <0.75) can reduce emissions by as much as 30% (Inoue, Matsushita, Nakanishi, & Okano (1993). Toyota lean combustion system—the third generation SAE, 930,873) and also it improves fuel efficiency by as much as 5-10%. However, the engine exhibits strong cyclic variation in heat release which may lead to instability and poor performance. A novel neural network (NN) controller is developed to control spark ignition (SI) engines at extreme lean conditions. The purpose of neuro-controller is to reduce the cyclic variation in heat release at lean engine operation even when the engine dynamics are unknown. The stability analysis of the closed-loop control system is given and the boundedness of all the signals is ensured. The adaptive NN does not require an offline learning phase and the weights can be initialized at zero or random. Results demonstrate that the cyclic variation is reduced significantly using the proposed controller developed using an experimentally validated engine model. The proposed approach can also be applied to a class of nonlinear systems that have a similar structure as that of the engine dynamics.     

Neural Network Controller Development and Implementation for Spark Ignition Engines With High EGR Levels

Past research has shown substantial reductions in the oxides of nitrogen (NO_x) concentrations by using 10% -25% exhaust gas recirculation (EGR) in spark ignition (SI) engines (see Dudek and Sain, 1989). However, under high EGR levels, the engine exhibits strong cyclic dispersion in heat release which may lead to instability and unsatisfactory performance preventing commercial engines to operate with high EGR levels. A neural network (NN)-based output feedback controller is developed to reduce cyclic variation in the heat release under high levels of EGR even when the engine dynamics are unknown by using fuel as the control input. A separate control loop was designed for controlling EGR levels. The stability analysis of the closed-loop system is given and the boundedness of the control input is demonstrated by relaxing separation principle, persistency of excitation condition, certainty equivalence principle, and linear in the unknown parameter assumptions. Online training is used for the adaptive NN and no offline training phase is needed. This online learning feature and model-free approach is used to demonstrate the applicability of the controller on a different engine with minimal effort. Simulation results demonstrate that the cyclic dispersion is reduced significantly using the proposed controller when implemented on an engine model that has been validated experimentally. For a single cylinder research engine fitted with a modern four-valve head (Ricardo engine), experimental results at 15% EGR indicate that cyclic dispersion was reduced 33% by the controller, an improvement of fuel efficiency by 2%, and a 90% drop in NO_x from stoichiometric operation without EGR was observed. Moreover, unburned hydrocarbons (uHC) drop by 6% due to NN control as compared to the uncontrolled scenario due to the drop in cyclic dispersion. Similar performance was observed with the controller on a different engine.     

Adaptive coordinated control of engine speed and battery charging voltage

In this paper, the control problem of auxiliary power unit （APU） for hybrid electric vehicles is investigated. An adaptive controller is provided to achieve the coordinated control between the engine speed and the battery charging voltage. The proposed adaptive coordinated control laws for the throttle angle of the engine and the voltage of the power-converter can guarantee not only the asymptotic tracking performance of the engine speed and the regulation of the battery charging voltage, but also the robust stability of the closed loop system under external load changes. Simulation results are given to verify the performance of the proposed adaptive controller.     

Adaptive coordinated control of engine speed and battery charging voltage

In this paper, the control problem of auxiliary power unit (APU) for hybrid electric vehicles is investigated.An adaptive controller is provided to achieve the coordinated control between the engine speed and the battery charging voltage. The proposed adaptive coordinated control laws for the throttle angle of the engine and the voltage of the powerconverter can guarantee not only the asymptotic tracking performance of the engine speed and the regulation of the battery charging voltage, but also the robust stability of the closed loop system under external load changes. Simulation results are given to verify the performance of the proposed adaptive controller.     

Position Control of a Flexible Manipulator Using a New Nonlinear Self-Tuning PID Controller

In this paper, a new nonlinear self-tuning PID controller(NSPIDC) is proposed to control the joint position and link deflection of a flexible-link manipulator(FLM) while it is subjected to carry different payloads. Since, payload is a critical parameter of the FLM whose variation greatly influences the controller performance. The proposed controller guarantees stability under change in payload by attenuating the non-modeled higher order dynamics using a new nonlinear autoregressive moving average with exogenous-input(NARMAX) model of the FLM. The parameters of the FLM are identified on-line using recursive least square(RLS) algorithm and using minimum variance control(MVC) laws the control parameters are updated in real-time. This proposed NSPID controller has been implemented in real-time on an experimental set-up. The joint tracking and link deflection performances of the proposed adaptive controller are compared with that of a popular direct adaptive controller(DAC). From the obtained results, it is confirmed that the proposed controller exhibits improved performance over the DAC both in terms of accurate position tracking and quick damping of link deflections when subjected to variable payloads.     

Model-based cold-start speed control scheme for spark ignition engines

This paper presents a model-based control scheme to the cold-start speed control in spark ignition (SI) engines. The multi-variable control algorithm is developed with the purpose of improving the transient performance of the starting engine speed: the control inputs are the fuel injection, the throttle and the spark advance (SA), while the engine speed and the air mass flow rate are the measured signals. The fuel injection is performed with a dual sampling rate system: the cycle-based fuel injection command is individually adjusted for each cylinder by using a TDC (top dead center)-based air charge estimation. The desired performance for speed regulation is achieved by using a coordinated control of SA and throttle operation. The speed error convergence of the closed loop system is proved for simplified, second-order model with a time-delay, and the robustness with respect to parameter uncertainties is investigated. The performance and the robustness with respect to modeling uncertainties of the proposed control scheme are tested using an industrial engine simulator with six cylinders.     

Microprocessor control of ignition advance angle

The ignition control requirements of an internal combustion petrol engine are reviewed and the benefits of accurate ignition control are discussed. A design for a microprocessor-based open-loop ignition controller is described and the experimental results obtained with this controller presented. Various means of achieving further improvements are suggested, including a closed-loop controller for optimum ignition timing under all conditions of engine wear. This strategy uses peak cylinder pressure angle as the feedback signal on which the adaptive control is based.     

基于累积平方误差–总平方波动指标的模型预测控制器性能评价及自愈

本文针对模型预测控制器实际投运中遇到性能下降问题,提出了一种基于累积平方误差(ISE)–总平方波动(TSV)指标的模型预测控制器性能评价及自愈方法.先基于累积平方误差(ISE)和总平方波动(TSV)指标对模型预测控制器进行实时性能评价,再根据无限时域模型预测控制器(MPC)的逆特性,基于ISE–TSV指标的分析,提出了一种MPC控制器的鲁棒自愈方法.在二级倒立摆的模型预测控制仿真与实验结果证明了所提自愈方法的可行性及有效性.     

Detection of model-plant mismatch in closed-loop control system

The performance of model-based control systems depends a lot on the process model quality, hence the process model-plant mismatch is an important factor degrading the control performance. In this paper, a new methodology based on a process model evaluation index is proposed for detecting process model mismatch in closed-loop control systems. The proposed index is the ratio between the variance of the disturbance innovation and that of the model quality variable. The disturbance innovations are estimated from the routine operation data by an orthogonal projection method. The model quality variable can be obtained using the closed-loop data and the disturbance model estimated by adaptive Least absolute shrinkage and selection operator (Lasso) method. When the order of the disturbance model is less than 2 or the process time delay is large enough, no external perturbations are required. Besides, the proposed index is independent of the controller tuning and insensitive to the changes in disturbance model, which indicates that the proposed method can isolate the process model-plant mismatch from other factors affecting the overall control performance. Three systems with proportional integral (PI) controller, linear quadratic (LQ) controller and unconstrained model predictive control (MPC) respectively are presented as examples to verify the effectiveness of the proposed technique. Besides, Tennessee Eastman process shows the proposed method is able to detect process model mismatch of nonlinear systems.     

混沌乌燕鸥算法优化发动机参数自整定PID控制

针对传统PID参数整定存在的问题,结合混沌乌燕鸥优化算法（Chaos Sooty Tern Optimization Algorithm, CSTOA）良好的搜索性能,提出了一种基于混沌乌燕鸥优化算法的航空发动机参数自整定PID控制方法（CSTOA-PID）。首先通过引入混沌映射的思路,改进了乌燕鸥优化算法（Sooty Tern Optimization Algorithm, STOA）。接着设计了性能指标加权的适应度函数,用来避免发动机供油量极大超调与急剧供油现象。最后对某型涡扇发动机的数学模型进行仿真验证,结果表明：在地面状态下,经CSTOA-PID控制器优化后的PID参数分别为4.31878、14、0.214426。CSTOA-PID控制器的参数整定效果都好于STOA-PID控制器和PID控制器,转速阶跃响应反应迅速,同时供油量出现的超调最小,证明了该方法的有效性和可行性。     

Simple adaptive air-fuel ratio control of a port injection SI engine with a cylinder pressure sensor

The problem of air-fuel ratio(AFR) control of the port injection spark ignition(SI) engine is still of considerable importance because of stringent demands on emission control. In this paper, the static AFR calculation model based on in-cylinder pressure data and on the adaptive AFR control strategy is presented. The model utilises the intake manifold pressure, engine speed, total heat release, and the rapid burn angle, as input variables for the AFR computation. The combustion parameters, total heat release,and rapid burn angle, are calculated from in-cylinder pressure data. This proposed AFR model can be applied to the virtual lambda sensor for the feedback control system. In practical applications, simple adaptive control(SAC) is applied in conjunction with the AFR model for port-injected fuel control. The experimental results show that the proposed model can estimate the AFR, and the accuracy of the estimated value is applicable to the feedback control system. Additionally, the adaptive controller with the AFR model can be applied to regulate the AFR of the port injection SI engine.     

Online linearization-based neural predictive control of air–fuel ratio in SI engines with PID feedback correction scheme

Model predictive control (MPC) frequently uses online identification to overcome model mismatch. However, repeated online identification does not suit the real-time controller, due to its heavy computational burden. This work presents a computationally efficient constrained MPC scheme using nonlinear prediction and online linearization based on neural models for controlling air–fuel ratio of spark ignition engine to its stoichiometric value. The neural model for AFR identification has been trained offline. The model mismatch is taken care of by incorporating a PID feedback correction scheme. Quadratic programming using active set method has been applied for nonlinear optimization. The control scheme has been tested on mean value engine model simulations. It has been shown that neural predictive control with online linearization using PID feedback correction gives satisfactory performance and also adapts to the change in engine systems very quickly.     

Drilling performance analysis of drill column machine using proposed neural networks

Air-ratio is an important engine parameter that relates closely to engine emissions, power, and brake-specific fuel consumption. Model predictive controller (MPC) is a well-known technique for air-ratio control. This paper utilizes an advanced modelling technique, called online sequential extreme learning machine (OSELM), to develop an online sequential extreme learning machine MPC (OEMPC) for air-ratio regulation according to various engine loads. The proposed OEMPC was implemented on a real engine to verify its effectiveness. Its control performance is also compared with the latest MPC for engine air-ratio control, namely diagonal recurrent neural network MPC, and conventional proportional–integral–derivative (PID) controller. Experimental results show the superiority of the proposed OEMPC over the other two controllers, which can more effectively regulate the air-ratio to specific target values under external disturbance. Therefore, the proposed OEMPC is a promising scheme to replace conventional PID controller for engine air-ratio control.     

基于混合制排队模型的SDN控制器性能评估研究

软件定义网络SDN将逻辑控制与数据转发相分离,提高了网络的灵活性和可编程能力,成为近年来未来网络领域的研究热点。SDN在实际应用部署时将面临控制器性能瓶颈的挑战,因而有必要理解SDN控制器的性能特性。为此,首先对SDN控制器中Packet-In消息的到达过程和处理时间进行分析,进而基于排队论提出了一种容量有限的SDN控制器性能评估模型M/M/1/m,推导得出了该模型的性能参数,包括:平均等待队长、平均等待时间、平均队列长度和平均逗留时间。最后,采用控制器性能测试工具Cbench对该模型进行了实验评估。实验结果表明:相对于现有其它模型,该模型的估计时延更接近于实际测量时延,可更精确地描述SDN控制器的性能。     

Reconstruction of cylinder pressure for SI engine using recurrent neural network

Model predictive control (MPC) frequently uses online identification to overcome model mismatch. However, repeated online identification does not suit the real-time controller, due to its heavy computational burden. This work presents a computationally efficient constrained MPC scheme using nonlinear prediction and online linearization based on neural models for controlling air–fuel ratio of spark ignition engine to its stoichiometric value. The neural model for AFR identification has been trained offline. The model mismatch is taken care of by incorporating a PID feedback correction scheme. Quadratic programming using active set method has been applied for nonlinear optimization. The control scheme has been tested on mean value engine model simulations. It has been shown that neural predictive control with online linearization using PID feedback correction gives satisfactory performance and also adapts to the change in engine systems very quickly.     

一种航空发动机导叶角度调节器控制方法研究

航空发动机静子导流叶片角度数字电子控制系统的性能和可靠性对发动机的正常工作十分重要;为获得发动机的最优性能,提高飞行可靠性,并保证压气机工作稳定性,文章提出了一种基于RBF (Radial Basis Function)神经网络的PID控制器,构建了3层神经网络数学模型;在AMESim软件平台上,建立了该航空发动机导叶控制系统的数学模型,在Matlab/Simulink中搭建了RBF神经网络控制器;仿真结果表明,在相同参数设置下,本文所设计的控制器与传统PID控制器相比能够实现导叶角度调节器作动筒位移的更加快速、精确控制,表明该控制器设计方法是可行、有效的.     

Robust forecasts and run-to-run control for processes with linear drifts

Processes experiencing linear drift over time are usually forecasted using a double exponentially weighted moving average (d-EWMA) filter. d-EWMA has incorrectly been claimed as an optimal filter for the integrated moving average (2,2) (IMA(2,2)) process, which is a stochastic equivalent of a process with linear drifts (ramps). It is shown that the optimal filter for such a process has a different structure but can be put in a similar form with same effective tuning parameters. The problem of batch-to-batch process gain variation (with known bounds) has been addressed by using a robust run-to-run control algorithm. This algorithm solves a minimax problem that determines the next run input adjustment by minimizing the worst-case predicted error. The conditions for equivalence of the minimax controller to a nominal model inverse based controller for a simple SISO system based on the type of model used and the nature of bounds have been investigated. An important implication of the equivalence result for nonlinear systems is pointed out. The proposed robust run-to-run controller formulation is tested on a number of examples including a chemical mechanical polishing (CMP) process model.     

Model based approach to closed loop control of 1-D engine simulation models

1-D engine simulation models are widely used for the analysis and verification of air-path design concepts to assess performance and therefore determine suitable hardware. The transient response is a key driver in the selection process which in most cases requires closed loop control of the model to ensure operation within prescribed physical limits and tracking of reference signals. Since the controller effects the system performance a systematic procedure which achieves close-to-optimal performance is desired, if the full potential of a given hardware configuration is to be properly assessed. For this purpose a particular implementation of Model Predictive Control (MPC) based on a corresponding Mean Value Engine Model (MVEM) is reported here. The MVEM is linearised on-line at each operating point to allow for the formulation of quadratic programming (QP) problems, which are solved as the part of the proposed MPC algorithm. The MPC output is used to control a 1-D engine model. The closed loop performance of such a system is benchmarked against the solution of a related optimal control problem (OCP). The system is also tested for operation at high altitude conditions to demonstrate the ability of the controller to respect specified physical constraints. As an example this study is focused on the transient response of a light-duty automotive Diesel engine. For the cases examined the proposed controller design gives a more systematic procedure than other ad hoc approaches that require considerable tuning effort.     

基于BF-PSO的船舶电站柴油机分数阶控制器

针对船舶电力系统的频率稳定性问题,对船舶电站柴油机调速系统设计了分数阶PIλDμ控制器。采用细菌觅食-粒子群混合优化(BF-PSO)算法对分数阶PIλDμ控制器参数进行优化整定,解决了分数阶PIλDμ控制器整定参数多、设计复杂的问题。对分别采用分数阶PIλDμ控制器和传统整数阶PID控制器的柴油机调速系统进行了仿真和对比。结果表明,在同等条件下优化得到的分数阶PIλDμ控制器能够有效抑制模型参数摄动,鲁棒性更强,具有更好的控制效果。