Yanjun Huang

Modelling and optimal energy-saving control of automotive air-conditioning and refrigeration systems

Air-conditioning and refrigeration systems are extensively adopted in homes, industry and vehicles. An important step in achieving a better performance and a higher energy efficiency for air-conditioning and refrigeration systems is a control-based model and a suitable control strategy. As a result, a dynamic model based on the moving-boundary and lumped-parameter method is developed in this paper. Unlike existing models, the proposed model lumps the effects of the fins into two equivalent parameters without adding any complexity and considers the effect produced by the superheated section of the condenser, resulting in a model that is not only simpler but also more accurate than the existing models. In addition, a model predictive controller is designed on the basis of the proposed model to enhance the energy efficiency of the air-conditioning and refrigeration systems. Simulations and experimental results are presented to demonstrate the accuracy of the model. The experiments show that an energy saving of about 8% can be achieved by using the proposed model predictive controller compared with the conventional on–off controller under the examined scenario. The better performance of the proposed controller requires electrification of the automotive air-conditioning and refrigeration systems so as to eliminate the idling caused by running the air-conditioning and refrigeration systems when a vehicle stops.

Robust path-following control for a fully actuated marine surface vessel with composite nonlinear feedback:

This paper presents a fast and accurate robust path-following control approach for a fully actuated marine surface vessel in the presence of external disturbances. The path following is realized by simultaneously converging the yaw rate and sway velocity to their respective desired values, which are generated according to the path-following demand. An improved combined control strategy using an integral terminal sliding mode (ITSM) based composite nonlinear feedback (CNF) technique considering the external disturbances, time-varying tracking reference, input saturations and transient performance improvement is proposed in this study. The proposed ITSM-CNF combines the advantages of the CNF control in improving the transient performance and of the ITSM control in guaranteeing good robustness and finite-time convergence. A continuous and smooth sliding mode controller, based on an integral nonsingular terminal sliding surface, is added to the CNF controller to eliminate chattering. The overall stability of the closed-loop system is strictly proved based on the Lyapunov method. Simulations verify the effectiveness of the ITSM-CNF controller in improving the transient path-following performance, inhibiting overshoots, eliminating steady-state errors, rejecting external disturbances and removing chattering effects, considering input saturations, varying path curvature and finite-time convergence.

Anti-idling systems for service vehicles: Modeling and experiments

Vehicles are a major source of fuel consumption and air pollution. Any improvement in their efficiency impacts the environment and economy positively. Service vehicles such as food delivery trucks have many loading and unloading stops during their daily work cycle. In these stops, their auxiliary devices need to be active and hence the engines run at its idling speed resulting in extremely low fuel efficiency. A regenerative auxiliary power system is proposed for anti-idling of service vehicles. This system reduces the engine idling and maximizes the regenerative braking energy by utilizing an additional battery. In this paper, different system configurations and possible options for integration of regenerative auxiliary power system to the vehicle powertrain are studied. Backward-looking scalable powertrain components modeling approach is utilized to create a flexible system model which can be easily modified for different vehicles. The full system model has scalability and composability features. A library for common components used in service vehicles is developed for ease of development of such anti-idling systems. Hardware-in-the-loop tests and a prototype model of regenerative auxiliary power system have been utilized for the laboratory evaluation in order to validate the model and characterize the regenerative auxiliary power system components.

Energy Management of Hybrid Electric Vehicles

This chapter presents a comprehensive review of energy-management strategy (EMS) systems utilized in hybrid electric vehicles (HEVs). HEVs are one of the most viable technologies to achieve energy savings and environmental protection goals. EMSs of HEVs have been studied extensively to improve the performance of HEVs and to speed up the industrialization of them. In this chapter, different types of power-management algorithms such as offline and online methods are briefly reviewed and classified. This chapter also presents a case study that shows three different energy0management approaches for the control of a series hybrid electric off-road vehicles using rules-based, dynamic programming, and model predictive control strategies. The performance of these three EMSs is evaluated and compared.

Multi-axle/articulated bus dynamics modeling: a reconfigurable approach

ABSTRACT This paper proposed a unified model including yaw and roll dynamics for any axle or articulation configuration of buses by using a reconfigurable approach. First, all the possible existing configurations of buses are introduced, including the axle/articulation configuration, powertrain configuration, and active chassis control configuration. Consequently, the research is motivated by a key question: how can we develop a unified model that is inclusive and configurable to all of the above bus configurations? To develop the model, three layers of the modeling process are presented step by step. The magic formula and vertical load transfer are discussed to formulate the tyre model. It is noted that the case of the articulated bus is presented in an independent section but how it is included and unified in a general form is also explained. Finally, a modeling validation of axle or articulation configuration cases is performed and the comparative results to high-fidelity models show the feasibility, efficiency, and convenience of the reconfigurable approach. As the crucial feature, the resulting model can be potentially applied to model-based controller design in any buses without reformulating the model. This will greatly benefit the vehicle dynamics control and also future autonomous buses. Although the focus of this paper is buses, the proposed approach actually covers any multi-axle/articulated vehicles, like trucks, tractor-trailers.

A new coordinated control strategy for tracked vehicle ride comfort

To improve tracked vehicle ride comfort and minimize weapons vibration, a coordinated control strategy is developed for tracked vehicles semi-active suspension systems. A model with eight degrees-of-freedom for a tracked vehicle equipped with magnetorheological dampers is established, and is followed by the formulation of a sliding mode controller. The proposed control algorithm is a localized-based controller that can change its target location in the tracked vehicle to where it is needed most. A co-simulation system model including a six-wheel tracked vehicle multi-body dynamics model, coordinated control strategy, and magnetorheological damper force allocator is developed to analyze the ride performance under bump and random road excitations. The simulation results demonstrate that the proposed strategy is very effective in improving the vehicles ride performance and is much better than the traditional skyhook controllers. The innovation of this paper can be concluded as the coordinated control strategy can simultaneously improve vertical acceleration and pitch acceleration for the hull, which is of great importance for combat situations.

A novel tripped rollover prevention system for commercial trucks with air suspensions at low speeds

This paper presents a novel system to avoid tripped rollovers at low-speed operations for commercial vehicles with air suspension systems. This is of particular significance since truck rollovers have become a serious road safety problem, which usually lead to severe injuries and fatalities. Several active anti-rollover systems have been proposed in the past two decades; however, most of them focus on untripped rollover prevention instead of the tripped rollovers. Up to now, very few pieces of literature discuss the approaches that are used to avoid tripped rollovers of trucks. Furthermore, the air suspension is widely used for commercial vehicles, thus it provides an opportunity to prevent rollovers when properly manipulated. Therefore, a novel tripped rollover prevention system is proposed for trucks at low-speed operations with air suspensions. A roll dynamics model with an air spring is built to investigate the dynamic behavior and the time response of the whole system. More importantly, the feasibility of this new anti-rollover system is discussed and verified by the co-simulations in TruckSim and MATLAB/Simulink under two possible tripped rollover conditions.

Integrated Torque Vectoring Control for a Three-Axle Electric Bus Based on Holistic Cornering Control Method

An integrated chassis control framework that consists of a basic chassis controller and a torque vectoring controller is designed for a three-axle electric bus with distributed motor-driven and active rear steering subsystems. In the basic chassis controller, the active speed limiting control is integrated for antisideslip and antirollover purposes, and the interaxle torque distribution ratio is optimized for energy economy. Meanwhile, the active rear steering control is designed for the tire-wear coordinating purpose. In the torque vectoring controller, the model-based motion control algorithm based on the holistic cornering control method is designed, by which a torque increment is generated at each wheel to change the plane motion states of the vehicle. To solve the optimal torque increment vector, a real-time constrained quadratic programming problem is formulated. The constraints related to the wheel torque limits, the tire friction limits, and the anti-wheel-slip requirements are constructed and converted as the upper and lower bounds of the increments of the longitudinal tire forces. To verify the performance of the control framework, a Trucksim-Simulink cooperative test platform is established. The test results show satisfactory performances on energy economy, anti-wheel-slip, and the safety and stability of the motion control.

MPC-based power management strategy for a series hybrid electric tracked bulldozer

In this brief, a model predictive control (MPC) is developed for the first time to solve the optimal energy management problem in tracked bulldozers equipped with advanced series hybrid powertrains. Hybrid bulldozers use two distinct power sources for propulsion, and their complex powertrain architecture requires the coordination of all subsystems to achieve target performances in terms of fuel economy, exhaust emissions. This method is applied to a series hybrid electric vehicle, using a linearized model in state space formulation and a linear MPC algorithm, based on Quadratic Programming (QP), to find a feasible suboptimal solution. The MPC solution is then compared with the dynamic programming algorithm, which requires the entire driving profile to be known priori, guarantees the optimality and is used here as the benchmark solution. The effect of the parameters of the MPC (length of prediction horizon) is also investigated. The results from comparing the MPC solution and the rule-based control strategy indicate that there is an approximately 5.2%improvement in fuel economy.