Cédric Nouillant

FEEDFORWARD AND CRONE FEEDBACK CONTROL STRATEGIES FOR AUTOMOBILE ABS

Summary As mechatronic subsystems and especially new emerging technologies for brake systems are more and more developed, a new control architecture for ABS is proposed. The control architecture is designed using both feedback and feedforward controls that command pressure-controlled proportional servo-valves. The methods are developed to compensate for the uncertainty associated with the state of the road surface. The advantages of this strategy compared to the existing ABS strategy are discussed including simulations results using a complete vehicle and brake system model.

Catalytic converter modeling for optimal gasoline-HEV energy management

A simple multi-0D model of a 3-Way Catalytic Converter (3WCC) is built from physical equations, integrating the temperature dynamics and a pollutant emission conversion map. The validated model involves complexity and performances suitable to be integrated in a high fidelity powertrain model of a gasoline-Hybrid Electric Vehicle (HEV). Next, a pollutant constrained optimal energy management is derived from the Pontryagin Minimum Principle. The approach allows the joint minimization of pollution and fuel consumption with only one parameter to tune, by considering all the standardized pollutant emissions. The proposed strategy significantly reduces pollutant emissions with only a slight fuel consumption increase. Using a complex HEV model shows the feasibility of the pollution constraint integration in on-line energy management.

3WCC Temperature Integration in a Gasoline-HEV Optimal Energy Management Strategy

For a gasoline-hybrid electric vehicle (HEV), the energy management strategy (EMS) is the computation of the distribution between electric and gasoline propulsion. Until recently, the EMS objective was to minimize fuel consumption. However, decreasing fuel consumption does not directly minimize the pollutant emissions, and the 3-way catalytic converter (3WCC) must be taken into account. This paper proposes to consider the pollutant emissions in the EMS, by minimizing, with the Pontryagin minimum principle, a tradeoff between pollution and fuel consumption. The integration of the 3WCC temperature in the EMS is discussed and finally a simplification is proposed.

Pollution Constrained Optimal Energy Management of a Gasoline-HEV

In Hybrid Electric Vehicles (HEV), the electrical hybridization offers different ways to reduce the fuel consumption: kinetic energy recuperation during vehicle deceleration, possibility of stopping the engine, and intelligent Energy Management System (EMS). Besides, with the future more stringent standards, there is a need to integrate the pollutant emissions in the EMS, since strictly reducing the fuel consumption can increase the emissions. The paper presents an optimal energy management strategy with constraints on pollutant emissions for gasoline-HEV, taking into account the 3-Way Catalyst Converter (3WCC). Based on a complete model of the powertrain, a mixed fuel consumption / pollutant emissions performance index is minimized with the Pontryaguin Minimum Principle (PMP) and two states, the battery State Of Charge and the 3WCC temperature. Simulation results are presented showing that simply including the 3WCC dynamics in the pollutant emissions leads to a 1-state problem, easier to solve and giving better results for reducing fuel consumption and pollutants emissions, with a lesser use of the battery.

Effect of the Crone Suspension Control System on Braking

Abstract Semi-active or active suspensions not only increase driving comfort, but also permit the control system to be switched over if required in order to improve the transmission of forces at the points of contact between tire and road surface by minimizing the dynamic wheel loads. It may also be possible to use these systems to control wheel load distribution and, thus, influence braking or steering performance by changing the distribution of normal forces between the front and rear axles. This article examines the effect of the CRONE suspension control system on braking. The central idea is to use continuously variable dampers and fast load levelling devices to distribute the normal forces of tire between the front and rear axles. The basis principle is explained using known dynamic properties of active suspension, vehicles and tires. The effect of active suspension on vehicle response during braking is then evaluated using computer simulations from a two-wheel vehicle model.

Gasoline-HEV Equivalent Consumption and Pollutant Minimization Strategy

This article proposes a strategy which works on the fuel consumption / pollutant compromise with a gasoline Hybrid Electric Vehicle (HEV). First, a pollutant-constrained optimal energy management is derived from the Pontryagins Minimum Principle (PMP). Using only one parameter and considering standardized pollutant emissions, this approach is validated on a high-fidelity HEV model. Then, an online approach called the Equivalent Consumption and Pollutant Minimization Strategy (ECPMS), is explained and applied on a Hybrid Hardware In the Loop (Hy-HIL) test bench. This strategy reproduces the fuel consumption / pollutant trade-off with one tuning parameter and reduces pollutant emissions for a light fuel consumption penalty.

Modelling of Hydractive CRONE Suspension as a Hybrid System

Abstract Mechatronic subsystems have been extensively developed in automotive applications as they increase performance compared to passive components. The modelling and operation of Hydractive CRONE suspension as a hybrid system are now presented

Computation of eco-driving cycles for Hybrid Electric Vehicles: Comparative analysis

In this paper, the calculation of eco-driving cycles for a Hybrid Electric Vehicle (HEV), using Dynamic Programming (DP), is investigated from the solving method complexity viewpoint. The study is based on a comparative analysis of four optimal control problems formulated using distinct levels of modeling. Starting with three state dynamics (vehicle position and speed, battery state-of-charge) and three control variables (engine and electric machine torque, gear-box ratio), the number of state variables is reduced to two in a first simplification. The other two simplifications are based on decou-pling the optimization of the control variables into two steps: an eco-driving cycle is calculated supposing that the vehicle is propelled only by the engine. Then, assuming that the vehicle follows the eco-driving cycle calculated in the first step, an off-line energy management strategy (torque split) for an HEV is calculated to split the requested power at the wheels between the electric source and the engine. As is shown, the decreased complexity and the * Corresponding author. decoupling optimization lead to a sub-optimality in fuel economy while the computation time is noticeably reduced. Quantitative results are provided to assess these observations.

The Hydractive CRONE Suspension: Operation Principle and Stability Study

Mechatronic subsystems have been extensively developed in automotive applications as they increase performance compared to passive components. The Hydractive CRONE suspension based on fractional differentiation is presented as a hybrid system undergoing an infinite sequence of autonomous switchings. The modelling and operation of Hydractive CRONE suspension as a hybrid system are presented. Finally the stability of Hydractive CRONE suspension is demonstrated using the maximum principle extended to hybrid systems.Copyright

On the use of Dynamic Programming in eco-driving cycle computation for electric vehicles

This paper considers the problem of eco-driving for electric cars. This problem is formulated as an Optimal Control Problem (OCP) aiming at minimizing the vehicles energy consumption over fixed time and distance horizons. The impact of battery parameter variations and auxiliary power demands on the optimal vehicle velocity computation are studied from a model complexity viewpoint. Simulation results are presented and discussed to illustrate the suggested simplifications.