Model Predictive Control Algorithm Research Articles

Precision Post-Stall Landing Using NMPC With Learned Aerodynamics

In this paper, we present an approach for achieving precision post-stall landings with medium-sized Group 1 Unmanned Aerial Systems (UAS). To do this, we employ an aggressive dive-and-stall maneuver to significantly reduce maneuver distance, time, and touchdown speed. Our approach relies on a nonlinear model predictive control (NMPC) algorithm and learned aerodynamic coefficients to achieve accuracy and reliability in the presence of wind disturbances. We demonstrate our approach in hardware with a 60-inch wingspan, 4.2 kg fixed-wing UAS, and show the ability to land with low speed and high accuracy using minimal throttle.

Improved Kalman-Filter-Based Model-Predictive Control Method for Trajectory Tracking of Automatic Straddle Carriers

This paper considers the trajectory tracking problem for a class of automatic straddle carriers (ASCs) with external interferences and the overturning constraints. First, the steering and the dynamics of the ASC are analyzed and the mathematical model of the ASC is established. Then, considering the impact of external interferences on the trajectory tracking accuracy, an improved dynamic Kalman filter is designed in order to obtain the state estimation of the ASC. Based on the obtained state estimation, a model-predictive control method is proposed which takes the anti-overturning constraints into account. In addition, the improved Kalman-filter-based model-predictive control (iKFMPC) algorithm is summarized for the considered ASC to travel smoothly along the given trajectory while meeting the overturning resistance. Finally, simulation analyses demonstrate the effectiveness and superiority of the proposed method.

Control strategy for dynamic operation of multiple chillers under random load constraints

Under the influence of building load stochasticity and thermal inertia of central air conditioning system, the lag of control strategy makes it difficult for the cooling source system to meet the cooling demand of users in real time, which affects the operational energy efficiency ratio of the cooling source system. In this regard, this paper proposes a chiller dynamic optimization method based on Markov chain model predictive control algorithm, which studies the optimization of parallel operation characteristics of multiple chillers on the basis of correcting the occurrence of small probability events and avoiding frequent chiller starts and stops, reveals the prediction law of hourly load distribution of the future air conditioning system, explores the balance point between the prediction time of building load and the calculation time of chiller control strategy, provides a theoretical basis and reference for determining the time limit of the optimal calculation and the output of the optimal control strategy. The study provides a theoretical basis and reference for determining the time limit of the optimal calculation and the output of the optimal control strategy. It is found that the optimal control strategy not only has good optimization effect, but also the confidence is significantly increased by 56.7%.

Research on automatic driving control strategy based on improved model predictive control

As a new technology direction in the automotive industry in recent years, automatic driving technology has played an important role in reducing traffic accidents, promoting energy conservation and emission reduction, and improving the efficiency of high-speed and urban roads. As one of the key technologies of autonomous vehicles, the performance of control algorithm greatly affects the smoothness of vehicle driving and the accuracy of track tracking. In order to consider the lateral control and longitudinal control accuracy at the same time, and ensure that the vehicle travels according to the given trajectory, this paper first establishes the vehicle kinematics model, and improves the traditional model predictive control algorithm, which realizes the high dynamic control of the desired trajectory while ensuring the vehicle stability and comfort. Finally, based on the built real vehicle test platform for automatic driving, the acceleration and deceleration test and the high-speed serpentine test are designed. By analyzing the test data, it can be seen that the control algorithm proposed in this paper can effectively achieve the vehicle trajectory tracking, and the control accuracy is improved.

A Distributed Compensation Method for Active Power Filters Based on Model Predictive Control and Kalman Filter Algorithm

Research on global harmonic mitigation against distributed and high‐proportioned nonlinear loads in modern distribution networks has received extensive attention. In this paper, a distributed compensation method for active power filters (APFs) is proposed, which utilizes a small number of APFs with adjustable reference to alleviate the global voltage distortion caused by a large number of distributed nonlinear loads. The model predictive control (MPC) is employed to calculate the optimal current reference for compensators at each optimization moment by predicting the system's performance in a certain future time period. Furthermore, the Kalman filter (KF) algorithm is used to estimate the initial harmonic voltage for the MPC, reducing the unfavorable effects of the model uncertainty and measurement noise. The test results based on a seven‐bus distribution network in MATLAB are provided to verify the effectiveness of the proposed method. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

Positioning of Unmanned Underwater Vehicle Based on Autonomous Tracking Buoy.

This paper presents a novel method for the dynamic positioning of an unmanned underwater vehicle (UUV) with unknown trajectories based on an autonomous tracking buoy (PUVV-ATB) that indirectly positions the UUV using ultra-short baseline measurements. The method employs a spatial location geometric model and divides the positioning process into four steps, including data preprocessing to detect geometric errors and apply mean filtering, direction capture, position tracking, and position synchronization. To achieve these steps, a new adaptive tracking control algorithm is proposed that does not require trajectory prediction and is applied to the last three steps. The algorithm is deployed to the buoy for tracking simulation and sea trial experiments, and the results are compared with those of a model predictive control algorithm. The autonomous tracking buoy based on the adaptive tracking control algorithm runs more stably and can better complete the precise tracking task for the UUV with a positioning error of less than 10 cm. This method breaks the premise of trajectory prediction based on traditional tracking control algorithms, providing a new direction for further research on UUV localization. Furthermore, the conclusion of this paper has important reference value for other research and application fields related to UUV.

Model predictive anti-spin thruster control for efficient ship propulsion in irregular waves

In seagoing ships in waves, the torque and thrust of the propeller may vary with the submergence depth of the propeller. A large ship motion can cause ventilation and loss of effective disc area, which degrade the ship’s propulsion efficiency. Electric or electrified ships powered by electric motors can respond quickly to such load variations, unlike conventional ships powered by internal combustion engines. This paper proposes a model predictive anti-spin thruster control algorithm that can improve the propulsion efficiency of electric ships by controlling the rotational speed of the propeller with consideration of time-varying load conditions. The weight of the cost function for optimizing the propulsion efficiency is adjusted by using the propeller’s submergence predicted by an autoregressive model. The feasibility of the proposed algorithm is shown through numerical simulations of ship motions and propeller depth variation in irregular waves. The performance of the proposed algorithm is validated and compared with that of shaft speed and anti-spin thruster controllers, and the results are discussed.

Model Predictive Controller Design Based on Residual Model Trained by Gaussian Process for Robots

Model mismatch is inevitable in robot control due to the presence of unknown dynamics and unknown perturbations. Traditional model predictive control algorithms are usually based on constant value assumptions and are not able to overcome the degradation of controller performance due to model mismatch. In this paper, a model predictive control (MPC) algorithm based on Gaussian process regression (GPR) is proposed. Firstly, the kinematic equations of the mobile robot are established by the mechanistic analysis method; similarly, the dynamics of the mobile robot system are modeled using the second-class Lagrangian equations. Secondly, the problem of stability and reliability degradation due to model mismatch during the operation of mobile robot is considered. This paper uses a MPC algorithm with a main model plus residual model to solve the MPC closed-loop control strategy. The state at each moment is decomposed into a predicted state based on the first-principles model and a residual state. The residual state is learned by GPR in real-time and used to compensate for deviations between the real process model and the predicted model. The proposed method requires fewer data samples, enhancing the technique’s practicality. Finally, the simulation results show that the proposed algorithm is more stable and achieves the desired tracking faster. Compared with the MPC algorithm, the arrival time of the system is reduced by 28% and the speed error is controlled within 0.07.

Constrained linear output regulation via measurement output feedback model predictive control

Recently, the output regulation problem with input constraints for incrementally stable plants was solved by an error feedback model predictive control (MPC) algorithm. This paper further considers the case with both state and input constraints for linear systems and uses a measurement output feedback MPC algorithm to solve the problem. By relaxing two restrictions, the result of this paper can handle a larger class of linear systems than the existing result. Due to the uncontrollability of the augmented system composed of the plant and the exosystem, a key assumption in the literature fails, we manage to overcome this difficulty by introducing novel tightened constraints and the terminal constraint. As a result, the proposed algorithm solves the linear output regulation problem in the presence of both state and input constraints. The effectiveness of our design is illustrated by a numerical example.

Autonomous overtaking control considering the velocity change of obstacle vehicles on two-lane highways

Aiming at the speed change of obstacle vehicles in the process of autonomous ground vehicle (AGV) overtaking on two-lane highways, an overtaking control method including trajectory planning and trajectory control is proposed. First, the reference overtaking trajectory of the AGV is planned in stages (lane changing, passing and merging) using fifth order polynomials satisfying stability and comfort constraints. The initial planning trajectory may be unsafe due to the speed change of obstacle vehicles. So a collision prediction algorithm is built to predict two kinds of dangerous situations in real time: AGV collides with the leading vehicle during lane changing, and AGV collides with the oncoming vehicle during merging. Secondly, the potential field of the obstacle vehicles embedded with the relative speed is established and combined with the road potential field as the risk indicator. Then, combining the nonlinear model predictive control algorithm and risk index, the overtaking trajectory is replanned in real time with the initial trajectory as reference. Finally, a lateral path tracking controller based on model predictive control and a longitudinal speed tracking controller based on sliding mode control are established to track the planned trajectory rapidly and stably. To verify the performance of the proposed method, overtaking in three cases is simulated, and vehicle responding curves are obtained. The results show that the proposed control method can achieve safe and stable overtaking.

Formula omitted]-gap metric based multi-model predictive control of an ocean current turbine system with blade pitch failures

In this article, a method of combining multiple linear models is developed and used by an advanced model predictive control algorithm for ocean current turbine flight control. The developed model bank consists of faulty and healthy linear models created for the ocean current turbine system. Each linear model is used to compute individual control actions using the model predictive control framework, which are combined to generate the aggregate control action that is applied to the system. A weighted average defined by the ν-gap distance between the current linear approximation of system dynamics and each individual linear system is used to compute the aggregate control action. The multi-model predictive control strategy is applied to control the ocean current turbine to mitigate performance degradation that may occur due to failures in the system. The proposed control framework’s effectiveness is shown with the renewable power generation improvement during a faulty case.

Research on Path Tracking of Articulated Steering Tractor Based on Modified Model Predictive Control

With the development of agricultural mechanization and information technology, automatic navigation tractors are becoming a more common piece of farm equipment. The accuracy of automatic navigation tractor path tracking has become critical for maximizing efficiency and crop yield. Aiming at improving path tracking control accuracy and the real-time performance of the traditional model predictive control (MPC) algorithm, the study proposed an adaptive time-domain parameter with MPC in the path tracking control of the articulated steering tractor. Firstly, the kinematics model of the articulated steering tractor was established, as well as the multi-body dynamics model by RecurDyn. Secondly, the genetic algorithm was combined with MPC. The genetic algorithm was used to calculate the optimal time domain parameters under real-time vehicle speed, vehicle posture and road conditions, and the adaptive MPC was realized. Then, path tracking simulations were conducted by combining RecurDyn and Simulink under different path types. Compared with the traditional MPC algorithm under the three paths of U-shaped, figure-eight-shaped and complex curves, the maximum lateral deviations of the modified MPC algorithm were reduced by 59.0%, 24.9% and 13.2%, respectively. At the same time, the average lateral deviation was reduced by 72%, 43.5% and 20.3%, respectively. Finally, the real path tracking tests of the articulated steering tractor were performed. The test results indicated that under the three path tracking conditions of straight line, front wheel steering and articulated steering, the maximum lateral deviation of the modified MPC algorithm was reduced by 67.8%, 44.7% and 45.1% compared with the traditional MPC. The simulation analysis and real tractor tests verified the proposed MPC algorithm, considering the adaptive time-domain parameter has a smaller deviation and can quickly eliminate the deviation and maintain tracking stability.

A deep reinforcement learning approach to energy management control with connected information for hybrid electric vehicles

Considering the importance of the energy management strategy for hybrid electric vehicles, this paper is aiming at addressing the energy optimization control issue using reinforcement learning algorithms. Firstly, this paper establishes a hybrid electric vehicle power system model. Secondly, a hierarchical energy optimization control architecture based on networked information is designed, and a traffic signal timing model is used for vehicle target speed range planning in the upper system. More specifically, the optimal vehicle speed is optimized by a model predictive control algorithm. Thirdly, a mathematical model of vehicle speed variation in connected and unconnected states is established to analyze the effect of vehicle speed planning on fuel economy. Finally, three learning-based energy optimization control strategies, namely Q-learning, deep Q network (DQN), and deep deterministic policy gradient (DDPG) algorithms, are designed under the hierarchical energy optimization control architecture. It is shown that the Q-learning algorithm is able to optimize energy control; however, the agent will meet the ”dimension disaster” once it faces a high-dimensional state space issue. Then, a DQN control strategy is introduced to address the problem. Due to the limitation of the discrete output of DQN, the DDPG algorithm is put forward to achieve continuous action control. In the simulation, the superiority of the DDPG algorithm over Q-learning and DQN algorithms in hybrid electric vehicles is illustrated in terms of its robustness and faster convergence for better energy management purposes.

A Double-Layer Model Predictive Control Approach for Collision-Free Lane Tracking of On-Road Autonomous Vehicles

This paper proposes a double-layer model predictive control (MPC) algorithm for the integrated path planning and trajectory tracking of autonomous vehicles on roads. The upper module is responsible for generating collision-free lane trajectories, while the lower module is responsible for tracking this trajectory. A simplified vehicle model based on the friction cone is proposed to reduce the computation time for trajectory planning in the upper layer module. To achieve dynamic and accurate collision avoidance, a polygonal distance-based dynamic obstacle avoidance method is proposed. A vertical load calculation method for the tires is introduced to design the anti-rollover constraint in the lower layer module. Numerical simulations, with static and dynamic obstacle scenarios, are conducted on the MATLAB platform and compared with two state-of-the-art MPC algorithms. The results demonstrate that the proposed algorithm outperforms the other two algorithms regarding computation time and collision avoidance efficiency.

Trajectory Planning and Tracking for Four-Wheel Independent Drive Intelligent Vehicle Based on Model Predictive Control

<div class="section abstract"><div class="htmlview paragraph">This paper proposes a dynamic obstacle avoidance system to help autonomous vehicles drive on high-speed structured roads. The system is mainly composed of trajectory planning and tracking controllers. The potential field (PF) model is introduced to establish a three-dimensional potential field for structured roads and obstacle vehicles. The trajectory planning problem that considers the vehicle’s and tires’ dynamics constraints is transformed into an optimization problem with muti-constraints by combining the model predictive control (MPC) algorithms. The trajectory tracking controller used in this paper is based on the 7 degrees of freedom (DOF) vehicle model and the UniTire tire model, which was discussed in detail in previous work [<span class="xref">25</span>, <span class="xref">26</span>]. The controller maintains good trajectory tracking performance even under extreme driving conditions, such as roads with poor adhesion conditions, where the car’s tires enter the nonlinear region easily. The innovation of this paper lies in introducing a high-fidelity vehicle model and a muti-conditions UniTire tire model with high precision obtained after parameter identification through tire test data. In addition, the nonlinear relationship between tire lateral force and slip angle is expressed as a linear function. This method updates the equivalent cornering stiffness in the linear function by solving the slope of the secant of the tire cornering characteristic curve at the current moment online, which solves the problem of high computational complexity caused by applying complex tire models in the control system. The co-simulation results of Simulink and CarSim show that the designed system has good dynamic obstacle avoidance and driving stability performance under driving conditions with high speed and poor road adhesion.</div></div>

Cooperative predictive control for arbitrarily mixed vehicle platoons with guaranteed global optimality

AbstractThis paper studies the cooperative control problem of a mixed vehicle platoon, which is composed of connected autonomous vehicles (CAVs) and human‐driven vehicles (HDVs) in an arbitrary order. An alternating direction method of multipliers (ADMM) based distributed model predictive control (DMPC) algorithm is proposed for CAVs to lead the mixed vehicle platoon travelling in a string with anticipated inter‐vehicle spacing and a desired velocity. First, the mixed vehicle platoon is divided into multiple interrelated sub‐platoons with any two adjacent sub‐platoons having a common CAV, and then a generic model is constructed for each sub‐platoon based on the intelligent driver model for HDV and the kinematic model for CAV, respectively. Second, a local MPC controller is designed for each sub‐platoon to optimize the control inputs of CAVs with the objective of minimizing the position and velocity errors of all vehicles in the sub‐platoon, and then the ADMM is utilized to obtain the global optimal solution among local MPC controllers of all sub‐platoons. Finally, numerical simulations and experiments are carried out to verify the effectiveness of the proposed DMPC algorithm, the results of which reveal that it can reduce the computation cost significantly and ensure the control performance comparable to the centralized MPC algorithm.

Approximate Dissipativity of Cost-Interconnected Systems in Distributed Economic MPC

We consider dissipativity properties of interconnected systems in the context of distributed economic model predictive control (MPC), with the subsystems being interconnected through their stage cost functions. The isolated subsystems, i.e., when neglecting the coupled portion of the individual stage costs, are assumed to be dissipative with respect to a specific supply rate related to their local stage cost function, which is commonly used in an economic MPC context. Based on these local dissipativity properties and the interconnection structure, a corresponding (approximate) dissipativity property for the overall system is inferred, which is structured and provides performance bounds for overall system operation. The resulting structured dissipativity property is exploited in the design and analysis of a distributed economic MPC algorithm. Numerical examples visualize the theoretical findings and the effectiveness of the proposed algorithm.

Spatiotemporal learning-based stochastic MPC with applications in aero-engine control

To deal with the issue of model uncertainty, extensive stochastic MPC methods have been investigated, where the uncertainties are typically assumed to follow given statistical distributions. However, in practical scenarios, the statistical properties of model uncertainties may depend on certain hyperparameters varying both temporally and spatially. For instance, in the applications of aero-engine control, different types of uncertainties may occur under different operational conditions, such as flight altitudes and Mach numbers, which are dynamically changing. Traditionally, the stochastic MPC methods may not be able to handle these types of uncertainties directly. Therefore, we propose a spatiotemporal learning-based stochastic model predictive control algorithm to study the stochastic optimal control problem with dynamically changing uncertainties, by constructing spatiotemporal Gaussian processes (GPs) to approximate the uncertainties based on measurement data. Since the spatiotemporal GPs may be difficult to evaluate with long processing time series, we present a state–space representation of GPs to employ computationally efficient Kalman filtering. Then, we derive a computationally tractable control strategy by parameterizing the controller and reformulating the cost and chance constraints, and analyze the corresponding recursive feasibility and closed-loop stability. Finally, the proposed algorithm is applied to the compressor control of the aero-engine, and the comparisons with other MPC controllers are demonstrated to show the effectiveness of our methods.

Observer-based model predictive control for uncertain NCS subject to hybrid attacks via interval type-2 T–S fuzzy model

In this study, an observer-based model predictive control (MPC) algorithm is addressed for an uncertain discrete-time nonlinear networked control system (NCS) subject to hybrid malicious attacks by using interval type-2 Takagi–Sugeno (IT2 T–S) fuzzy theory. Hybrid malicious attacks, including two typical attacks, i.e., denial-of-service (DoS) attacks and false data injection (FDI) attacks, are considered in the communication networks. Under DoS attacks, the control signals will be interfered, which cause the degradation of signal-to-interference-plus-noise ratio, then lead to packets loss. Under FDI attacks, the false signals are injected and output signals are modified so that the system performance is deteriorated. For the NCS subject to hybrid attacks, a secure observer that can resist FDI attacks is devised and a fuzzy MPC algorithm that can solve the controller gains is proposed. Besides, by updating the bound of augmented estimation error, the recursive feasibility can be guaranteed. Finally, illustrative examples are given to show the effectiveness of proposed scheme.

Data-driven worst case model predictive control algorithm for propylene distillation column under uncertainty of top composition

Composition soft sensors have wide application in the distillation process. In this study, considering the limitation of the prediction ability of the composition soft sensor, a data-driven worst case model predictive control of propylene distillation column is proposed to hedge against the uncertainty of top composition. Firstly, based on the compartmental method and the dynamic mechanism model, a linear state space model of the distillation column is constructed. Aiming at dealing with the uncertainty of top propylene content caused by composition soft sensor, the data-driven uncertainty set is constructed by the combination of principal component analysis and kernel density estimation based on the historical data. Then, the certainty equivalent, traditional worst case, data-driven worst case, set-point tracking and offset-free model predictive control algorithm are designed. Finally, a case study of composition control in a propylene distillation column is carried out. Compared with other strategies, the proposed algorithm ensures the quality of the product while achieving small quality surplus and low operating cost.