Model Predictive Control in Milling based on Support Vector Machines

Since much attention has been paid to the accuracy of prediction models in chiller plant, the practicality and feasibility of models are often compromised for superior performance. In this paper, a data-driven model and online predictive control strategy are presented for a typical chiller plant to optimize its overall performance and energy consumption from the perspective of real-time application. The model predictive controller is developed based on the multivariable linear regression (MLR) model. Meanwhile, the ordinary least squares (OLS) estimation technique was adopted to identified and update the model coefficients. The input variables of the developed model are the temperature difference of chilled water and the temperature difference of cooling water, which are much easier to obtain in a practical system compared to variables such as water flow and part load ratio, thereby rendering an excellent model capable of easy implementation and duplication. The MLR model-based online predictive control strategy is tested and evaluated in a real chiller plant system. The results of application indicate that the online predictive control strategy can enhance the global COP values by 6.52% on average and reduce electricity consumption by 2.45% daily compared to the local control strategy.

This paper discusses the model-based predictive controller design of networked nonlinear systems with communication delay and data loss. Based on the analysis of the closed-loop networked predictive control systems, the model-based networked predictive control strategy can compensate for communication delay and data loss in an active way. The designed model-based predictive controller can also guarantee the stability of the closed-loop networked system. The simulation results demonstrate the feasibility and efficacy of the proposed model-based predictive controller design scheme.

A model predictive control for a multi-chiller system in data center considering whole system energy conservation

Multi-power sources are included in hybrid electrical vehicles, which leads to multi-driving modes co-existing when driving the vehicle. However, the frequent driving mode switching (DMS) will probably need the engine to be started frequently, which can result in extra fuel consumption. So, avoiding unnecessary DMS should be fully considered when designing the control strategy. For solving this problem, a model predictive control (MPC) strategy integrating Markov chain driving intention identification is put forward. First, the component models of the powertrain system are established. Second, according to the real driving cycle data, a driving intention model based on the Markov chain is designed according to the real driving cycle data. Then the MPC-based control strategy aiming at reducing DMS times is proposed by integrating the cost of DMS. Finally, the proposed control strategy is contrasted with three other control strategies to verify its validity in reducing the mode switching times and improving the fuel economy.

Nonlinear model predictive control for the space heating system of a university building in Norway

A type of recurrent neuro-fuzzy network is proposed in this paper to build long-term prediction models for nonlinear processes. The process operation is partitioned into several fuzzy operating regions. Within each region, a local linear model is used to model the process. The global model output is obtained through the centre of gravity defuzzification which is essentially the interpolation of local model outputs. This modeling strategy utilizes both process knowledge and process input output data. Process knowledge is used to initially divide the process operation into several fuzzy operating regions and to set up the initial fuzzification layer weights. Process input output data are used to train the network. Network weights are such trained so that the long-term prediction errors are minimized. Through training, membership functions of fuzzy operating regions are refined and local models are learn. Based on the recurrent neuro-fuzzy network model, a novel type of nonlinear model-based long range predictive controller can be developed and it consists of several local linear model-based predictive controllers. Local controllers are constructed based on the corresponding local linear models and their outputs are combined to form a global control action by using their membership functions. This control strategy has the advantage that control actions can be calculated analytically avoiding the time consuming nonlinear programming procedures required in conventional nonlinear model-based predictive control. The techniques have been successfully applied to the modeling and control of a neutralization process.

In power system operation and control, automatic generation control (AGC) scheme is used to maintain the balance in between the net generation and the total load in a system by supplying sufficient power with good quality. Controller plays an important role in AGC scheme. This paper presents a control scheme based on model predictive control (MPC) concept for multiarea power system in deregulated scenario. For guaranteed stability each area controller is designed independently. MPC controller is designed in such a way that for any load perturbation, generators can regulate the real power output to settle down deviations in frequency and tie line power exchange at desired values. The proposed MPC control scheme has been implemented for deregulated two area thermal power system. The performance of MPC controller is also checked for 75 bus Indian power system. Various load conditions has been considered to evaluate the performance of controller. The results and performance analysis are presented to justify the robustness & effectiveness of control scheme. The comparative performance analysis of MPC scheme and conventional proportional integral controller (PID) control is also presented.

Development, analysis and application of a predictive controller to a small-scale district heating system

Predefined-time control has been extensively implemented in marine control systems due to its capability to enhance transient performance and achieve superior control specifications. However, inaccurate control execution resulting from faulty actuators can compromise this control strategy and critically undermine system performance. To address this challenge, this paper propose a predefined-time model predictive fault-tolerant control strategy for unmanned surface vessels (USVs) while considering actuator failures and ocean disturbances. Firstly, a novel predefined-time model predictive control (PTMPC) strategy is designed by incorporating contraction constraints derived from an auxiliary predefined-time control system into the proposed optimization framework. This ensures that the resulting control variables guarantee predefined-time convergence of tracking errors when applied to the USV system. Furthermore, a long short-term memory-based neural network for disturbance prediction is integrated into the control strategy, leveraging its exceptional capability in modeling temporal sequences to achieve accurate forecasting of ocean disturbances. Thirdly, the proposed control scheme utilizes its integrated fault observation mechanism to actively compensate for actuator failures through real-time fault estimation, ensuring predefined-time convergence performance while providing rigorous guarantees of closed-loop stability and feasibility. Finally, simulation results demonstrate the efficacy and superiority of the proposed algorithm.

Brain-machine interfaces (BMIs) are human-machine integration systems that provide an interface between the brain and a machine to sense cortical neuronal activity for the purpose of restoring impaired motor tasks. In our previous work [1], an optimal design of BMIs based on artificial sensory feedback was developed using model predictive control which relied on neuronal activity in the form of spiking. From a real implementation perspective, a more generalized framework that utilizes spiking is proposed in this paper. Specifically, a charge-balanced intra-cortical micro-stimulation (ICMS) current and a network of spiking neurons are adopted to compensate the lost feedback information. Next, an artificial sensory feedback framework using the network of spiking neurons is designed based on model predictive control (MPC) strategy, and an optimization problem is formulated according to this framework. Since the charge-balanced ICMS current is composed of several integer parameters, the optimization problem also includes some integer decision variables and is hard to be solved. In this paper, a heuristic population-based search algorithm called particle swarm optimization (PSO) algorithm is used to solve this optimization problem. Considering the updated particles may violate the input constraints, additional constraints are designed to guarantee that the decision variables can satisfy the input constraints. Finally, simulation results show the effectiveness of the designed closed-loop BMIs during recovery of natural performance.

This paper proposes an improved constrained networked model predictive tracking control design for the chamber pressure of a coke furnace under uncertainty and packet losses. Unlike conventional constrained model predictive control (MPC) strategies that have a limitation in the consideration of both set-point tracking and the dynamic process responses, the system state variables and output tracking errors are combined and thus can be regulated simultaneously in the new MPC scheme. Based on such advantages, there are more degrees of freedom for the subsequent controller design and improved system performance can then be obtained. Case studies on the regulation of chamber pressure of a coke furnace under process uncertainties and packet losses are investigated to verify the proposed approach in comparison with typical traditional constrained MPC schemes.

This paper presents a model predictive voltage control method for single-inductor multiple-output (SIMO) DC/DC converters operating in the continuous conduction mode (CCM). The state-space model for a SIMO DC/DC converter system is formulated and a Model Predictive Control (MPC) strategy, which has the capability to track the reference voltage automatically and reduce the impact of cross regulation problem, is proposed to regulate the system. Considering that the switches in the converter only have ON/OFF modes, the quadratic programming algorithm is employed to obtain the MPC's solution. Simulation studies are conducted in MATLAB/Simulink to verify the performance of the proposed method.

A habituating blood glucose control strategy for the critically ill

Implementing a personalised feeding strategy for each individual batch of a bioprocess could significantly reduce the unnecessary costs of overfeeding the cells. This paper uses lactate measurements during the cell culture process as an indication of cell growth to adapt the feeding strategy accordingly. For this purpose, a model predictive control is used to follow this a priori determined reference trajectory of cumulative lactate. Human progenitor cells from three different donors, which were cultivated in 12-well plates for five days using six different feeding strategies, are used as references. Each experimental set-up is performed in triplicate and for each run an individualised model-based predictive control (MPC) controller is developed. All process models exhibit an accuracy of 99.80% ± 0.02%, and all simulations to reproduce each experimental run, using the data as a reference trajectory, reached their target with a 98.64% ± 0.10% accuracy on average. This work represents a promising framework to control the cell growth through adapting the feeding strategy based on lactate measurements.

The class of model-based predictive controllers (MBPCs) has been quite successful at overcoming many of the well-known difficulties inherent in nonminimum phase (NMP) systems, e.g., flexible structures, and among the various MBPCs, Unified Predictive Control (UPC) was selected for the control tasks in this paper. Two methods are used to model the tip force of a flexible manipulator. Modal expansion (summation) is a pole but not zero preserving approach, while Infinite Product Expansion preserves both poles and zeros of a system. It is shown that in a flexible structure framework the difference between the exact and modal expansion zeros is significant. The effect of transmission zero mismatch will be observed in a closed loop system, especially when a model based controller is used. Simulation results show that when a UPC is designed based on the modal expansion model, it destabilizes the closed loop system when an exact model is used as the plant. This suggests a severe problem in implementing the designed UPC experimentally. The use of an exact model in a model-based controller design procedure, such as UPC, is therefore suggested. (Author)