Qifang Liu

Position Control of Electric Clutch Actuator Using a Triple-Step Nonlinear Method

For a novel electric clutch actuator, a nonlinear feedforward-feedback control scheme is proposed to improve the performance of the position tracking control. The design procedure is formalized as a triple-step deduction, and the derived controller consists of three parts: steady-state-like control; feedforward control based on reference dynamics; and state-dependent feedback control. The structure of the proposed nonlinear controller is concise and is also comparable to those widely used in modern automotive control. Finally, the designed controller is evaluated through simulations and experimental tests, which show that the proposed controller satisfied the control requirement. Comparison with proportional-integral-derivative control is given as well.

Automotive Control: the State of the Art and Perspective

Abstract Automotive control technology plays a significant role for the sustainable development of auto-industry. Under gradually fierce circumstance of competition around the world, how to strengthen our capacity of independent research and development of auto-control technology through the innovation of theory and method presents a grand challenge of our time. This paper introduces the state of the art of automotive control focusing on the power-train control, active safety control and new energy vehicle control, then summarizes their common problems and finally puts forward a series of perspective for the future researches.

Modeling and Control of the Fuel Injection System for Rail Pressure Regulation in GDI Engine

To obtain the precise injection in GDI engines, this paper presents a model-based rail pressure control scheme. First, a mathematical model is derived for the fuel rail injection system based on hydrodynamics and the bulk modulus of elasticity and simplified reasonably for the controller design. The system is uncontrollable at the point where the pump pressure is equal transiently to the rail pressure. A simple controller is designed for driving the system to the regular case where the pump pressure is larger than the rail pressure. In order to deal with system nonlinear, a nonlinear controller is derived and rearranged in the structure of feedforward feedback. The feedforward is related to the reference dynamics and the gain is state-dependent, while the feedback includes a state-dependent PD/PID error feedback and a state feedback related to the characteristics of the fuel rail system. The structure of the controller benefits potentially to the engineering-oriented implementation. Second, robustness is analyzed in the framework of input-to-state stability, where the error induced from the controller implementation, disturbances, and uncertainties are lumped as an additive input. Finally, the designed control scheme is tested in the more realistic simulation model established in the AMESim environment and the results are satisfying.

ADRC based clutch slip control for automatic transmission

In this paper, an active disturbance rejection controller (ADRC) is proposed for the gear shift operation of automatic transmissions. With this approach, model uncertainties including steady state errors, unmodelled dynamics and disturbances which are known or unknown are treated as a total disturbance. The total disturbance can be estimated using the extended state observer (ESO), and a nonlinear state error feedback controller is designed to make the clutch speed difference tracking the desired reference. Finally, the designed controller is tested on an AMESim power-train simulation model. Simulation results are provided to demonstrate the effectiveness of the proposed control scheme.

Shift control of Dual Clutch Transmission using Triple-Step nonlinear method

Abstract The shift control, especially clutch slip control in inertia phase, is considered as a key issue of dual clutch transmission for improving driving comfort. For the shift is a complex nonlinear dynamic process combining engine states and road information, and these are often variable, so the clutch control system can be described as a nonlinear parameter-varying model. Moreover, a novel nonlinear approach is proposed for clutch control of shift process, the control objective is to obtain smooth gearshift in the limited shift time by making clutch slipping speed difference tracking the planned reference. The proposed method can be formalized as a triple-step procedure and this procedure provides a concise design process so that the derivation of the control law is simplified and straightforward. Finally, the simulation results in the environment of AMESim with a complete vehicle model show the efficiency of the proposed approach.

Idle speed controller design for SI engine based on ADRC

In this paper, an idle speed controller is designed in the framework of active disturbance rejection control (ADRC) for spark ignition (SI) engine. The SI engine model based on the mean value model is proposed. As the system can be considered as a cascade system, the developed controller incorporates a nonlinear state error feedback law (NLSEF) which handles the speed tracking and an ADRC controller based on the Extended State Observer (ESO) to deal with the unknown dynamics and disturbance of the engine system.The robustness stability of the controller is analyzed. Simulation results are provided to demonstrate the advantage and effectiveness of the controller.

Clutch slip control of automatic transmissions: A nonlinear feedforward-feedback design

To improve the shift quality of vehicle with clutch-to-clutch gear shifts, a nonlinear controller based on flatness is proposed for the clutch slip control during the inertia phase. A nonlinear feedforward control is designed in consideration of the system nonlinearities, and a linear feedback control is given to accommodate the model errors and the disturbances. The proposed control scheme has small computational demand and the complex nonlinear characteristics of powertrain system appear in their original form of lookup tables. Finally, the designed controller is tested on an AMESim powertrain simulation model, which contains a time-variant model of clutch actuators.

Active disturbance rejection control of common rail pressure for Gasoline Direct Injection engine

The rail pressure control in Gasoline Direct Injection (GDI) engines is considered as one of key issues for precise control of fuel injection. This paper presents a rail pressure controller based on the framework of active disturbance rejection control (ADRC). The detailed nonlinear model of the fuel injection system for GDI engine is carried out. Suitable model simplification is introduced for the controller design. According to the complex nonlinear system which contains internal uncertainties and external disturbance, a nonlinear state error feedback control and an extended state observer are applied to deal with the pressure tracking problem. Simulation results are provided to demonstrate the effectiveness of the proposed controller.

On-line Optimal Control of the Gearshift Command for Multispeed Electric Vehicles

A design method for the gearshift strategy in powertrain systems is proposed to explore the energy saving potential of an electric vehicle (EV) equipped with a multispeed automated manual transmission (AMT). The optimal gearshift schedule is obtained by solving a nonlinear time-varying optimal problem in the framework of model predictive control, wherein, the vehicle driveability, represented by the drivers power demand satisfaction, and battery efficiency are considered. The solution approach is developed basing on the combination of Pontryagins minimum principle and numerical methods, in addition to the real-time applications. Simulation results for a passenger EV with four-speed AMT on different drive cycles show that compared with the case of a standard gearshift strategy, an additional fuel saving can reach 3–5% and even more when considering road characteristic such as road slope. Furthermore, hardware in the Loop simulation for experimental validation is also given in this paper. Results indicate that both energy efficiency and computational speed are improved.

Fuel economy optimization of hybrid electric vehicles

Fuel economy optimization of hybrid vehicles is essentially solving the optimal energy management mode and shift schedule under specified system constraints so as to realize the optimal control of hybrid vehicles. However, the global optimal dynamic programming control strategy cannot use in the real-time control since the uncertainty of the driving environment, an optimization control strategy which can be used in the practice is proposed in this paper. Under knowing the running state information of the car on a predicted future time domain provided by the vehicles navigation system (GPS/GIS), this paper solve the optimal shift schedule and energy management mode which minimize the equivalent fuel consumption of the forecast time domain with the dynamic programming algorithm(DP), and then under the framework of model predictive control to realize the rolling optimization. Finally, the energy management mode and shift schedule of hybrid electric vehicles have been verified by the simulation, and the simulation results show the effectiveness of the optimization control strategy of the hybrid electric vehicles.