This paper presents automatic guidance control of a single-articulated all-wheel-steered vehicle being developed by the Korea Railroad Research Institute. The vehicle has an independent drive motor on each wheel except for the front axle. The guidance controller is designed so that the vehicle follows the given reference path within permissible lateral deviations. We use a three-input/three-output linearised model derived from the nonlinear dynamic model of the vehicle. For the purpose of simplifying the controller and making it tunable, we consider a decentralised control configuration. We first design a second-order decoupling compensator for the two-input/two-output system that is strongly coupled and then design a first-order controller for each decoupled feedback loop by using the characteristic ratio assignment method. The simulation results for the nonlinear dynamic model indicate that the proposed control configuration successfully achieves the design objectives.

-For automated guidance control of a magnetically guided-all wheel steered vehicle, it is necessary to have information about position and orientation of the vehicle, and deviations from the reference path in real time. The magnet reference system considered here consists of three magnetic sensors mounted on the vehicle and magnetic markers, which are non-equidistantly buried in the road. This paper presents an observer to estimate such position and orientation at the center of gravity of the vehicle. This algorithm is based on the simple kinematic model of vehicle and uses the data of wheel velocity, steering angle, and the discrete measurements of marker positions. Since this algorithm requires the exact values of initial states, we have also proposed an algorithm of determining the initial position and orientation from the 16 successive magnet pole data, which are given by the magnetic measurement system(MMS). The proposed algorithm is capable of continuing to estimate for the case that the magnetic sensor fail to measure up to three successive magnets. It is shown through experimental data that the proposed algorithm works well within permissible error range. 서 론The articulated vehicle is a new type of public transportation to combine the advantage of commuter buses and railroad vehicles. To achieve good tracking performance similar to railroad vehicle, these vehicles have to be equipped with a lateral guidance system. Such a lateral guidance system requires informations about the vehicles position to calculate the tracking errors relative to the path to be followed. In most cases, the absolute position of the vehicle cannot be measured continuously. msec. It turns out that the information necessary for the guidance control should be estimated at the intermediate time when the magnetic sensors are moving from a marker to next marker, so that this is continuously available for guidance control. Furthermore, it is required to estimate the position and orientation without large errors for the case that the MMS fails to detect three markers consecutively.In this paper, we propose an observer of estimating the vehicle position and orientation. The estimator is composed of an integration algorithm based on vehicle kinematic model, EKF, position update algorithm and orientation angle compensation algorithm using the MMS data. The EKF is used to calculate the vehicle velocity and the side-slip angle at a reference point of the vehicle by using wheel encoders and steering angles data. This is the similar method as one in [5]. The MMS update algorithm is used for estimating the absolute position of vehicle and the orientation angle compensation algorithm

-This paper is concerned with the robustness evaluations of the guidance controller for a bimodal tram which is being developed by the Korea Railroad Research Institute (KRRI). The bimodal tram is an all-wheel steered multiple-articulated vehicle as a new kind of transportation vehicle. This vehicle has to be equipped with an automatic guidance system. In [1], such a controller has been recently proposed. However, since the performance is affected by weight change of the vehicle due to number of the passenger, model parameter uncertainties depending on the state of friction and the elasticity of the tire, and a typhoon, the controller designed must be examined with these conditions. As expected, because the vehicle dynamics is highly nonlinear, for the sake of investigating the robustness of the controller we compose two simulation ways based on the vehicle models which are implemented by the ADAMS and the MATLAB/LabVIEW toolboxes. Different uncertainties and a typhoon disturbance have been considered for the simulation conditions. Simulation results are shown.