g-Woo Jeon

Design and implementation of HILS system for ABS ECU of commercial vehicles

The hardware in-the-loop simulation (HILS) system has historically been used in the development and testing of complex and costly systems such as military tactical missiles, aircraft flight control system, satellite control systems, and automotive systems. Especially in the automotive industry, HILS is an effective tool for design, performance evaluation and test of vehicle subsystems such as antilock brake system (ABS), active suspension system, and steering system. This paper describes a HILS model for an ABS/ASR application. Also the design and implementation of HILS system for development of the ABS ECU (electronic control unit) for commercial vehicles are presented. Fourteen degrees of freedom vehicle dynamics model is simulated in alpha-chip processor board. The proposed HILS system is tested by a basic ABS control algorithm. The HILS system simulation results show that the proposed HILS system maybe used to realistically test performance, stability, and reliability of the vehicle.

Development of antilock braking controller using hardware in-the-loop simulation and field test

This paper presents the control principles and algorithms for the antilock brake system (ABS) with pneumatic brake. Also a new simulation method, the hardware in-the-loop simulation (HILS), which includes hardware in the control and simulation loop, is presented. It includes pneumatic brake hardware between the controller input and simulated vehicle dynamics output. How to construct the HILS for antilock brake system of a vehicle is described. Also how to evaluate the antilock brake algorithms and electronic control unit (ECU) in laboratory is explained. If the HILS is used, functional tests of the newly developed antilock brake controller can be made in a short time using repeated experiments. As a result, times and costs needed for developing the new antilock brake controller can be reduced. Also the developed controller was equipped in a real vehicles and tested in the real test road for comparison. It can be said that the HILS is a good method for developing a new system especially in automotive applications, in which many trial and errors are required for practical implementation.

Performance evaluation of antilock brake controller for pneumatic brake system

Antilock brake system (ABS), equipped in a vehicle, increases safety because it prevents wheels from being locked up and minimizes the danger of skidding, allowing the vehicle to stop in a straight line. ABS also allows drivers to maintain steering control of a vehicle during emergency braking of it. So the vehicle can avoid obstacles or another vehicles on the road. This paper deals with an antilock brake controller for full-air brake system, which is widely used in heavy vehicles such as buses and trucks. Two methods of evaluating the ABS controller and the algorithms were focused on: laboratorial test and field test. For the laboratorial test, a hardware in-the-loop simulator (HILS) was made. This includes actual pneumatic brake hardware between the controller input and vehicle dynamics output, thus simulating a whole bus under braking in real time. This paper describes how the HILS of antilock brake system of a bus was constructed, and how this HILS can be used for evaluating the antilock brake algorithms and electronic control unit (ECU) in the laboratory. Using HILS, we could achieve functional tests needed in an ABS controller in a short time. As a result we could reduce time and cost needed for developing the controller for pneumatic brake. For the field test, a bus equipped with an ABS controller was driven and stopped in the test field, where severe road conditions exist. This paper also describes configurations of the data acquisition system for it. Finally we compared the results of the laboratorial HILS tests with those field tests and proved the HILS is a good method for developing a new system, especially in automotive applications.

A method for rotor vibration monitoring of induction motor by air-gap flux detection

This paper presents results of the finite-element (FE) analysis and experiment of air-gap flux variation in induction motor when rotor eccentricity phenomenon occurs. An accurate modeling and analysis of rotor vibration in the motor are made using air-gap flux simulation, and search coils are used for measuring the actual magnetic flux. The simulated vibration system with 4-poles, 380 [V], 7.5 [kW], 1,768 [rpm] induction motor is built, and search coils are designed and inserted under the stator wedge of the motor. The FE analysis results are compared with experiment test results, and it shows that it is an effective method for developing on-line monitoring system on rotor vibration of an induction motor.

Real-time test of aircraft brake-by-wire system with HILS & dynamometer system

In this paper, it is a study to valid a compatibility of digital control unit (DCU) for an aircraft brake system through a dynamometer test as well as HILS test. It is very important because results of this test are satisfied before installing on an aircraft. The dynamometer system is composed of dynamo, HILS (hardware-in-the-loop simulation) and velocity sensors installed on wheel and dynamo. The DCU was tested under various friction conditions in HILS and dynamometer test. The DCU with ABS control algorithm protected very well a wheel skid on high friction condition as well as low friction condition.

Development of a dynamic simulator for braking performance test of aircraft with anti-skid brake system

In this paper, the dynamic simulator with 5-D.O.F. aircraft dynamic model and ABS control h/w unit with ABS control algorithm are developed and are tested to depend on some conditions of gripping coefficient. ABS control h/w unit on wet or snowy runways as well as dry runways protects well against wheel skid.

Analysis of voltage distribution in stator winding of IGBT PWM inverter-fed induction motors

IGBT PWM inverter has been concerned that insulation breakdown and irregular voltage distribution on stator winding due to high rate of voltage rise (dv/dt) caused by high-frequency switching and impedance mismatch between inverter and motor. In this paper, voltage distribution in stator windings of induction motor driven by IGBT PWM inverter is studied. To analyze the irregular voltage of stator winding, high frequency parameter is computed by using finite element method (FEM). An equivalent circuit composed by distributed capacitances, inductance, and resistance is derived from these parameters. This equivalent circuit is then used for simulation in order to predict the voltage distribution among the turns and coils. The variable effect on rising time of the inverter and cable length on the voltage distribution is also presented. In order to experiment, an induction motor, 50 HP , with taps from one phase and a switching surge generator were built to consider the voltage distribution.

Comparison between software simulation and HIL simulation of antiskid brake system for aircrafts

Today, most fixed-wing aircrafts are equipped with an antiskid brake system (ABS). The ABS can modulate braking moments in the wheels optimally whenever an aircraft lands. So it can reduce landing distance and increase safeties. The ABS for an aircraft is mainly composed of braking moment modulators (hydraulic servo valves) and brake control unit in addition to the conventional hydraulic brake system. In this paper, a Mark IV type-fully digital-brake controller is studied. For the development of its control algorithms, a 5 degree of freedom (DOF) aircraft landing model is composed in the form of the Matlab/Simulink model at first. Then antiskid control algorithms using wheel decelerations and slips are made. The developed algorithms are tested in software simulations using state-flow toolboxes in the Matlab/Simulink model. Also, the hardware in-the-loop simulation (HILS) systems are made using real-time simulators, where hydraulic brake systems of a real aircraft, braking moment modulator and its controller are included as hardware components. Algorithms tested in software simulations are coded and downloaded into a newly developed digital signal processing (DSP) controller and the dynamics models are downloaded to real-time simulators and the simulations have been done in the same road conditions as software simulations. Both the software and HIL simulation results are presented.

Positioning control of magnetic levitation system by SMC

In this paper, we address two position control scheme; the lead-lag control and the sliding mode control for a stage system, which is levitated and driven by electric magnetic actuators. This consists of a levitating object (called platen) with 4 permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force for suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion by the vertical and horizontal forces. Dynamic equations of the stage system are derived simply. The sliding mode control algorithm is more effective than the lead-lag control algorithm to reduce effects from movements and disturbances of other axis.

High-precision control of magnetic levitation system

In this paper, we address two position control scheme; the lead-lag control and the sliding mode control for a stage system, which is levitated and driven by electric magnetic actuators. This consists of a levitating object (called platen) with 4 permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force for suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion by the vertical and horizontal forces. Dynamic equations of the stage system are derived simply. The sliding mode control algorithm is more effective than the lead-lag control algorithm to reduce effects from movements and disturbances of other axis.