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This paper presents a longitudinal control algorithm for an adaptive cruise control (ACC) with collision avoidance (CA) in multiple vehicle traffic situations. The proposed algorithm consists of a multi-target tracking filter, a primary target selection algorithm and an integrated ACC/CA system. The multi-target tracking filter is used to smooth the sensor signal, and makes it possible to apply to a control system. The primary target selection algorithm decides an in-lane target and provides the information to an integrated ACC/CA system in order to drive a subject vehicle smoothly and improve safety in complex traffic situations. Finally, the integrated ACC/CA system computes the desired acceleration. The performance and safety benefits of the multi-vehicle ACC/CA system is investigated via simulations using real data on driving. Simulation results show that the response of multi-vehicle ACC/CA system is more smooth and safer at a change of traffic situations.

Electro-hydraulic brake (EHB) provides improved braking and stability functions such as ABS, TCS, ESC, EBD, etc. It also removes complex mechanical parts for freedom of design, improves maintenance requirements and reduces unit weight. But, the EHB should be at least as reliable as the conventional hydraulic brake system. In this paper, the model-based fault diagnosis system is developed to monitor the brake status using the analytical redundancy method. The performance of the model-based fault diagnosis system is verified in simulations and demonstrates the effectiveness of the proposed system in various faulty cases.

Lane keeping assistant system (LKAS) is expected to reduce the driver workload with assisting the driver during driving and is regarded as a promising active safety system. For the proposed LKAS which requires cooperative driving between driver and the assistance system, a Model Based Predictive Controller (MBPC) is proposed to minimize the effect of system overshoot caused by the time delay from the vision-based lane detection system. In order to validate the proposed LKAS controller, a HIL (Hardware In the Loop) simulator is built using steering mechanism, single camera, torque motor, sensors, etc. The performance of the proposed system is demonstrated in various roadways.

A fault detection method with parity equations is proposed in this paper. Due to low cost implementation, the velocity of a motor is not measurable in EPB systems. Therefore, residuals are not reliable with a low resolution encoder to estimate the motor velocity. In this paper, we propose a fault detection method with sensorless estimation using current ripples. The method estimates position and velocity of the motor by detecting periodical oscillations of the armature current caused by rotor slots. This method could estimate position and velocity of the motor with less computational effort than a state observer. Moreover, the method is less sensitive to motor parameters than model-based estimation methods. The effectiveness of this method is validated with experimental data. The simulation results show that various faults have their own residual patterns. Therefore, we could detect the fault by monitoring the residual signals.

This paper presents three types of controllers for Electric Parking Brake (EPB) Systems: bang-bang, linear proportional (P), and nonlinear proportional (P) controller. Mechanical and electrical parts of EPB system are modeled and implemented using Modelica language. There is good agreement between simulation and experimental results. For the stability analysis, the EPB system is modeled as a state-dependent switched system with simplified friction dynamics. From simulation and experimental results, it turns out that the nonlinear P controller provides good uniformity in performance and robustness among them.

Wheel-slip control systems are able to control the braking force more accurately and can be adapted to different vehicles more easily than conventional ABS systems. But, in order to achieve the superior braking performance, real-time information about the vehicle status variables such as wheel slip ratio, tire force, etc is required. In this paper, a wheel slip controller based on the estimated braking force is developed for brake-by-wire systems. The proposed wheel slip control system is composed of the braking force monitor and robust slip controller. In the brake force monitor, the tire braking forces as well as the brake disk-pad friction coefficient are estimated. The robust wheel slip controller using the estimated tire braking force is designed based on the sliding mode control technique. This system determines the braking pressure as the control input and maintains the wheel slip at any given target slip.

This paper proposes a control and fault diagnosis method for a pressure sensor based brake control system. The proposed wheel brake pressure control method consists of feedforward and feedback controller, respectively. The main purpose of the feedforward controller is to set the operating point of the feedback control, and the purpose of feedback controller is to improve the control response and the steady state error characteristic. Also, the proposed fault diagnosis method consists of three processes: a fault detection process, a fault isolation process and a fault identification process. In the fault detection process, a fault is detected by the difference between the estimated signal and the measured signal. Then, in the fault isolation process, the location of the fault is determined. Finally, in the identification process, the size and effect of the fault are evaluated.

Recently, wheel slip controllers with controlling the wheel slip directly have been studied using the brake-by-wire actuator. The wheel slip controller is able to control the braking force more accurately and can be adapted to various different vehicles more easily than the conventional ABS systems. The wheel slip controller requires the information about the tire braking force and road condition in order to achieve the braking and stability control performance. In this paper, the tire braking forces are estimated considering the variation of the friction between brake pad and disk due to aging of the brake, moisture on the contact area or heating. In addition, the road friction coefficient is estimated without using tire models. The estimated performance of tire braking forces and the road friction coefficient is evaluated in simulations.

In this paper, a nonlinear dynamic engine model is introduced, which is developed to represent an SI engine over a wide range of operating conditions. The model includes intake manifold dynamics, fuel film dynamics, and engine rotational dynamics with transport delays inherent in the four-stroke engine cycles, and can be used for designing engine controllers. The model is validated with engine-dynamometer experimental data. The accuracy of the model is evaluated by the comparison of the simulated and the measured data obtained from a 2.0 L inline four-cylinder engine over wide operating ranges. The test data are obtained from 42 operating conditions of the engine. The speed range is from 1500 (rpm) to 4000 (rpm), and the load range is from 0.4 (bar) to WOT. The results show that the simulation data from the model and the measured data during the engine test are in good agreement.

The introduction of inexpensive cylinder pressure sensors provides new opportunities for precise engine control. This paper presents a control strategy of spark advance and air-fuel ratio based upon cylinder pressure for spark ignition engines. In order to extend the cylinder pressure based engine control to a wide range of engine speeds, the appropriate choice of control parameters is important as well as essential. For this control scheme, peak pressure and its location for each cylinder during every engine cycle are the major parameters for controlling the air-fuel ratio and spark timing. However, the conventional method requires the measurement of cylinder pressure at every crank angle degree to determine the peak pressure and its location. In this study, the peak pressure and its location were estimated, using a multi-layer feedforward neural network, which needs only five cylinder pressure samples at -40°, -20°, 0°, 20°, and 40° after TDC.

This paper presents a strategy to improve fuel atomization during warm-up. Heating the fuel inside the fuel-rail plans improvement on fuel atomization. In this experiment, the heated fuel-rail system is constructed to investigate the reduction effects on the size of the fuel droplet by fuel heating. The fuel atomization is examined by measuring Sauter Mean Diameter (SMD) of the fuel droplets from the three different types (two-hole, pintle, and six-hole) of injectors based upon the returnless heated fuel-rail system. The results show that the six-hole type injector with the heated fuel provides the best fuel atomization results in terms of SMD among three different types of injectors.