A major research topic in intelligent transportation systems (ITSs) is the development of systems that will be capable of controlling the flow of vehicular traffic through crossroads, particularly in urban environments. This could significantly reduce traffic jams, since autonomous vehicles would be capable of calculating the optimal speed to maximize the number of cars driving through the intersection. We describe the use of vehicle-to-vehicle (V2V) communications to determine the position and speed of the vehicles in an environment around a crossroad. These data are used to estimate the intersection point, and a fuzzy controller then modifies the speed of the cars without right of way according to the speed of the car with right of way. Experimental tests conducted with two mass-produced cars on a real circuit at the facilities of the Instituto de Automa?tica Industrial, Consejo Superior de Investigaciones Cienti?ficas, Madrid, Spain, gave excellent results.

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Controller for Urban Intersections Based on Wireless Communications and Fuzzy Logic

In an automatic transmission position control by a motor, it is determined whether the present instant belongs to a starting period, that is, the present instant is immediately after resetting of a control unit or application of power to it. If it is the starting period, an actual shift position that is detected from an output of an output shaft sensor for detecting a rotation position of a motor is set as an instructed shift position. With this measure, even if the control unit is reset for a certain reason while the vehicle is running, the instructed shift position is not changed in association with the resetting. This prevents trouble that the shift position is switched contrary to the intention of the driver, whereby the reliability of a position switching control can be increased.

Motor control apparatus

Adaptive actuator fault tolerant control for uncertain nonlinear systems with multiple actuators

Various methods, apparatuses, and systems in which a single-track vehicle has a retractable auxiliary-support wheel assembly and a computer control system. In an embodiment, the single-track vehicle has an elongated body. The retractable auxiliary-support wheel assembly mounts on both sides of the elongated body. The computer control system analyzes signals from one or more sensors to dynamically balance the single-track vehicle.

Computerized automated dynamic control system for single-track vehicles

This paper investigates the path-tracking problem for four-wheel-steering and four-wheel-driving electric vehicles with input constraints, actuator faults, and external resistance. A hybrid fault-tolerant control approach, which combines the linear-quadratic control method and the control Lyapunov function technique, is proposed. It not only maintains the vehicle's tracking performance in spite of faults, input constraints, and external resistance but also reduces the cost of the fault-tolerant process. A prototype vehicle from the Laboratoire d'Automatique, Ge?nie Informatique et Signal (LAGIS), is particularly focused on illustrating the applicability of our approach.

Optimal Fault-Tolerant Path-Tracking Control for 4WS4WD Electric Vehicles

In this thesis the objective is to optimize the control algorithms for the manual pulsed Gas Metal Arc Welding (GMAW) process, with the aim of enhancing the quality of welded joints. To be able to develop controllers for the GMAW process, and also for enabling process simulation, a mathematical model describing the GMAW process is developed. The mathematical model includes a description of the electrical circuit, the drop dynamics, and the melting rate, and also, the model includes criteria for drop detachments. Basically, the electrical circuit consists of the welding machine, the wires, the electrode, and the electrical arc. The drop is modelled as a mass-spring-damper system influenced by a number of external forces. Of these external forces the electromagnetic force is the most significant. Due to the importance of the electromagnetic force, a thorough derivation of the electromagnetic force is included in the thesis. The melting rate of the consumable electrode is modelled both from a statically (steady-state) point of view, and from a dynamically point of view. The static model is a simple equation describing the melting rate, while the dynamic model is more complex. The structure of GMAW control is discussed, and based on this discussion a general control structure is presented. This structure includes an arc length controller and a metal transfer controller, and also, an inner loop controlling the welding current. The current is assumed to be controlled by a traditional PI-controller, and therefore, this inner control loop is not considered in the thesis. For arc length control, a nonlinear controller based on feedback linearization is proposed, and robustness and performance are considered. For metal transfer control an approach based on obtaining a uniform drop size prior to pulse initiation is proposed. This is carried out by calculating the amount of melted electrode between the current pulses during the welding process. The purpose of the uniform drop size approach is to enhance the robustness of the drop detachment process. In addition to the arc length controller and the metal transfer controller, an arc length minimization algorithm is proposed for enhancing the ability to focus the arc, and also, to minimize the heat input into the workpiece. Simulation programs for testing the controllers and algorithms have been developed, and successful tests have been carried out.

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Advanced Control Methods for Optimization of Arc Welding

In this paper a model of an induction motor affected by stator faults is presented. Two different types of faults are considered, these are; disconnection of a supply phase, and inter-turn and turn-turn short circuits inside the stator. The output of the derived model is compared to real measurements from a specially designed induction motor. With this motor it is possible to simulate both terminal disconnections, inter-turn and turn-turn short circuits. The results show good agreement between the measurements and the simulated signals obtained from the model. In the tests focus is on the phase currents and the star point voltage as these signals are often used for fault detection.

Stator Fault Modelling of Induction Motors

Electrical steering of vehicles: fault-tolerant analysis and design

Electrical Steering of Vehicles - Fault-tolerant Analysis and Design

This paper presents a control system for manual pulsed Gas Metal Arc Welding (GMAW). This system consists of a current controller, which makes it possible to shape the current during welding, and two important components, which are the key issues discussed in this paper. These components include an arc length controller and a metal transfer controller. The arc length controller is based on a non-linear SISO model of the arc length process and uses feedback linearisation for cancellation of non-linear terms. The metal transfer controller uses a melting speed model to determine when liquid drops at the tip of the electrode should be detached. Tests are carried out in a simulation environment.

Jesper Sandberg Thomsen

Papers

Advanced Control Methods for Optimization of Arc Welding

Stator Fault Modelling of Induction Motors

Electrical steering of vehicles: fault-tolerant analysis and design

Electrical Steering of Vehicles - Fault-tolerant Analysis and Design

Control of pulsed gas metal arc welding