Rui He

Fault detection approach to EMB sensors based on dedicated observers

Dedicated Observer Scheme (DOS) was used for fault detection and isolation which adopted EMB (electro-mechanical braking) system. Base on the mechanical model of EMB, two independent Kalman filters were designed for the fault detection of EMB sensors. Computer simulation showed that DOS has made a good use at fault isolation and detection for EMB sensors, and it also had high real-time property.

Study on the stability of the steering torque feedback system considering the time delay and the system characteristics

The steering torque feedback system, as one of the most critical parts in a driving simulator or a steer-by-wire system, is used to generate an faithful or desired steering feel for drivers. This requires that the steering torque feedback system should stably simulate the steering feel for a sufficiently large range. There are many factors that can influence the stability region of the steering torque feedback system, such as the characteristics of the system, the time delay and other non-linear factors. In this paper, from the viewpoint of the system design, a stability criterion is derived using an energy-based approach. In particular, some influencing factors are quantitatively investigated and analysed in this paper, including the characteristics of the damping, friction and stiffness system, the time delay and other non-linear factors of the system. The stability criterion and the analysis results of these influencing factors can be used as guidelines for the design of a steering torque feedback system with the aim of achieving a better performance, such as appropriate parameters for the system damping, friction and stiffness, the maximum allowable time delay of the system and the design of the system control algorithms. As well as a finished steering torque feedback system, the stability region can also be calculated from the criterion using the system parameters. The derived stability criterion and analysis results of these influencing factors are all verified by both simulations and experiments.

Active Braking of an Electronic Brake Booster Facing Intelligent Automobile

In this paper, a novel electronic brake booster and an accurate pressure control method for engineering are put forward and consider the shortcomings of the existing braking system in active braking for intelligent driving. Together with the hydraulic control unit, they are comprised of two working modes: active braking for automatic drive and passive braking for driver intervention. For wheel cylinder pressure control, we translate the control problem of pressure to position tracking. The strong nonlinearity and the load-dependent friction make the position tracking control of the electro-mechanical brake booster more challenging. Consequently, a modified PI control architecture is presented with techniques of cascaded three closed loop PI controller, friction compensation based on friction model, and gain scheduling. Finally, based on dSPACE, we carried out the rapid prototyping tests of active braking and hardware in the loop tests covering full speed ACC conditions. The results show that pressure control, acceleration control, and speed control achieve optimal performance.

Modeling and fault analysis of EMB motor

In this paper, the simulink model of the Brushless DC Motor (BLDCM), whichs the actuator of the Electro-Mechanical Braking (EMB) system, was established. And then, typical faults of the BLDCM were analyzed. These faults included the faults of the motor, the power transistor, and the Hall sensor. In addition, the detailed theoretical analysis of these faults simulation results and their effect on braking ability are given.

The co-simulation platform for intergrated chassis control

A co-simulation platform for ICC (Integrated Chassis Control) system was built under the MATLAB and AMEsim environment. A vehicle dynamic model was developed using the MATLAB software, and a dynamic response model for hydraulic brake system was built using the AMESim software. Then, the data exchanged through the AMEsim special interface module and the MATLAB S-function. The co-simulation platform was modified by hardware in the loop experiment. And the modified co-simulation platform was used under the typical condition for the performance of ICC.