[Show abstract][Hide abstract] ABSTRACT: In this work, a solution for clustering and tracking obstacles in the area covered by a LIDAR sensor is presented. It is based on a combination of simple artificial intelligence techniques and it is conceived as an initial version of a detection and tracking system for objects of any shape that an autonomous vehicle might find in its surroundings. The proposed solution divides the problem into three consecutive phases: 1) segmentation, 2) fragmentation detection and clustering and 3) tracking. The work done has been tested with real world LIDAR scan samples taken from an instrumented vehicle.
[Show abstract][Hide abstract] ABSTRACT: In this paper, the problem of crossing the inter-sections is studied. A controller is designed based on a hybrid automaton. The design procedure is presented into two cases. The problem of crossing with one automatic car and one manual car from intersection is studied in case one. The safe crossing (i.e. fixing safe distance between two automatic car)of two automatic cars is studied in case two. Simulation is done by the model which is identified by the real data from the car Citroen C3. Simulation results show the efficiency of the controller in both cases.
[Show abstract][Hide abstract] ABSTRACT: Cars capable of driving in urban environments autonomously are today one of the most challenging topics in the intelligent transportation systems (ITS) field. This paper deals with the evolution of Clavileño -a gas propelled vehicle-in its automation process towards a fully autonomous car driving in a real word. So, the required modifications for a mass-produced car in order to equip it with automatic driving capabilities; the on-board sensor systems to analyze the environment; the autonomous guidance system as well as the cooperative maneuvers implemented and the local evaluation system are presented. The system has been tested in a controlled area with other vehicles in several experiments with good results.
[Show abstract][Hide abstract] ABSTRACT: Artificial intelligence techniques applied to control processes are particularly useful when the elements to be controlled are complex and can not be described by a linear model. A trade-off between performance and complexity is the main factor in the design of this kind of system. The use of fuzzy logic is specially indicated when trying to emulate such human control actions as driving a car. This paper presents a fuzzy system that cooperatively controls the throttle and brake pedals for automatic speed control up to 50km/h. It is thus appropriate for populated areas where driving involves constant speed changes, but within a range of low speeds because of traffic jams, road signs, traffic lights, etc. The system gets the current and desired speeds for the car and generates outputs to control the two pedals. It has been implemented in a real car, and tested in real road conditions, showing good speed control with smooth actions resulting in accelerations that are comfortable for the car's occupants.
[Show abstract][Hide abstract] ABSTRACT: Reducing the number of traffic accidents is a declared target of most governments. Since dependence on driver reaction is the main cause of road accidents, it would be advisable to replace the human factor in some driving-related tasks with automated solutions. To automate a vehicle, it is necessary to control the actuators of a car, i.e., the steering wheel, accelerator, and brake. This paper presents the design and implementation of an electro-hydraulic braking system consisting of a pump and various valves, allowing the control computer to stop the car. It is assembled in conjunction with the original circuit for the sake of robustness and to permit the two systems to halt the car independently. This system was developed for installation in a commercial Citroën C3 Pluriel of the AUTOPIA program. Various tests were carried out to verify its correct operation, and an experiment showing the integration of the system into the longitudinal control of the car is described.
Full-text · Article · Feb 2010 · International Journal of Automotive Technology
[Show abstract][Hide abstract] ABSTRACT: The adaptive cruise control systems are capable of adapting the speed to the precedent car in highways as long as the car does not stop. However, in urban areas where the traffic flow can cause stop and go maneuvers continuously, this system is not very useful due to the necessity of re-start it once the car is stopped. In this paper, a speed control based on fuzzy logic for continuous stop and go manoeuvres is presented where the speed car is up to ten kilometers per hour. The system has been tested with two Citroën C3 vehicles, one of them full automated, in the Instituto de Automática Industrial facilities with great results.
No preview · Article · Oct 2009 · Revista Iberoamericana de Automatica e Informatica Industrial (RIAI)
[Show abstract][Hide abstract] ABSTRACT: Los sistemas de control de crucero adaptativo permiten, adecuando la velocidad, realizar el seguimiento del vehículo precedente en autopistas mientras este vehículo no se detenga. Sin embargo, en áreas urbanas donde la congestión del tráfico obliga a continuas detenciones, este sistema pierde funcionalidad ya que, una vez detenido el vehículo, el conductor debe reactivar el sistema. En este artículo, se presenta un sistema de control de velocidad mediante lógica borrosa para situaciones continuadas de parada y arranque, en las que la velocidad del vehículo es inferior a diez kilómetros por hora. El sistema se ha implantado y probado en un vehículo comercial con excelentes resultados.
Full-text · Article · Oct 2009 · Revista iberoamericana de automática e informática industrial (RIAI)
[Show abstract][Hide abstract] ABSTRACT: Loss of accuracy in automated vehicle position control systems due to Global Positioning System (GPS) signal quality is currently one of the most studied research topics in the field of Intelligent Transportation Systems (ITS). This paper presents an integrated positioning system that combines a GPS with onboard sensors and an Inertial Measurement Unit (IMU) to perform autonomous vehicle guidance. Depending on GPS precision, the system discriminates which positioning is most appropriate from three different possibilities: 1) real-time kinematic differential global positioning system (RTK-DGPS) is working at the highest positioning accuracy (1 cm). In this instance, GPS data are used as the main sensory supply; 2) total DGPS signal loss. Now, the IMU control system takes control; 3) centimeter accuracy is lost. In this instance, GPS and IMU measurements are integrated to determine the true positioning. This system has been installed in a Citroën C3 Pluriel car, where all the actuators were automated to achieve human-like driving. Experimental results show the car's behavior in diverse situations and prove that the test-bed vehicle can maintain automatic navigation even when GPS positioning is unavailable. The results also show the need to combine sensory information to obtain optimum navigation control in any circumstance.
No preview · Article · Oct 2008 · Revista iberoamericana de automática e informática industrial (RIAI)
[Show abstract][Hide abstract] ABSTRACT: Uno de los objetivos más importantes de los Sistemas Inteligentes de Transporte (ITS) es evitar la pérdida de precisión en el posicionamiento y guiado del vehículo, debido a la disminución en la calidad de la señal del Sistema de Posicionamiento Global (GPS). En este artículo, se presenta un sistema de posicionamiento formado por la combinación de un GPS con una unidad de medida inercial ayudada por los sensores embarcados en el coche para realizar el guiado. En función de la precisión proporcionada por el GPS, el sistema discrimina entre tres posibles comportamientos: 1) Si la precisión es centimétrica, el GPS se encarga en solitario del guiado. 2) Si no se recibe la señal GPS, el control lo toma la unidad inercial. 3) Si la precisión de la señal del GPS no es centimétrica, la posición del vehículo se calcula mediante una combinación de ambas medidas. El sistema se ha instalado en un Citroën C3 Pluriel. Los resultados muestran un correcto comportamiento del vehículo en diferentes situaciones y prueban la necesidad de integrar la información sensorial para realizar un control de navegación óptimo.
Full-text · Article · Oct 2008 · Revista iberoamericana de automática e informática industrial (RIAI)
[Show abstract][Hide abstract] ABSTRACT: Cybercars and dual mode vehicles are presently the most innovative testbeds for vehicular automation applications. The definition of standards and control architectures of the different automatic vehicle onboard systems is a necessary task to build a final prototype to be produced. Several classical architecture definitions have been made in the field of mobile robotics. These architectures are capable of dealing with sensorial inputs and environment and procedural knowledge to manage the different actuators of mobile robots in order to accomplish their missions. Autonomous vehicles are conceived as a link between mobile robotics and the field of vehicular technology, obtaining cars that may be as autonomous as a mobile robot but circulating in high demand environments and in different conditions, as compared to robots. In this paper we present the control architecture used in AUTOPIA program, used for automating mass produced cars. This architecture is to deal with sensorial information and wireless communication as main sensorial input and manages the three fundamental actuators in a car: throttle, brake and steering wheel. The final aim of this architecture is to cover an automatic driving system that can manage a set of maneuvers of a car in the same way human drivers do. At this moment, straight circulation, curve circulation, adaptive cruise control, stop and go and overtaking maneuvers are available and research continues in order to increment its number
[Show abstract][Hide abstract] ABSTRACT: The steering wheel automatic control for autonomous vehicles is presently one of the most interesting challenges in the intelligent transportation systems field. A few years ago, the researchers had to adapt motors or hydraulic systems in order to automatically manage the trajectory of a vehicle but, due to the automotive industry technological development, a new set of tools built into the mass produced cars allow the feasibility to be computer-controlled. This is the case of the electronic fuel injection, sequential automatic gearbox or the Electric Power Steering (EPS). In this paper we present the development of an autonomous vehicle's EPS control, based on a two layer fuzzy controller. The necessary computer and electronic equipment has been installed in a Citroen C3 Pluriel mass produced testbed vehicle and a set of experiments has been carried out to demonstrate the feasibility of the presented controllers in real situations.
[Show abstract][Hide abstract] ABSTRACT: The automatic control of the speed and the steering of a vehicle are two of the main steps in order to develop autonomous intelligent vehicles. In this paper, a development of steering control for automated cars based on fuzzy logic and its related field tests are presented. Artificial intelligence techniques are used for controlling a broad range of systems, trying to emulate the human behaviour when classical control models are too much complex and require a lot of design time. Particularly, fuzzy logic control techniques are well proved success methods for managing systems where there appear to be limitations for classical control. Our control system has been installed in two Citroen Berlingo testbed vans whose steering wheel has been automated and can be controlled from a computer. The main sensorial input is a RTK DGPS that gives us positioning with one-centimeter precision. The results of the realized experiments show a human like system performance with adaption capability to any kind of track.
[Show abstract][Hide abstract] ABSTRACT: There is a broad range of robotics technologies that are currently being applied to the generic topic of intelligent transportation systems (ITS). One of the most important research topics in this field is adaptive cruise control (ACC), aiming at adapting the vehicle speed to a predefined value while keeping a safe gap with regard to potential obstacles. For this purpose, a monocular vision system provides the distance between the ego vehicle and the preceding vehicle on the road. The complete system can be understood as a vision-based ACC controller, based on fuzzy logic, which assists the velocity vehicle control offering driving strategies and actuation over the throttle of a car. This controller is embedded in an automatic driving system installed in two testbed mass-produced cars operating in a real environment. The results obtained in these experiments show a very good performance of the vision-based gap controller, which is adaptable to all speeds and safe gap selections.
[Show abstract][Hide abstract] ABSTRACT: There is a broad range of diverse technologies under the generic topic of intelligent transportation systems (ITS) that holds the answer to many of the transportation problems. In this paper, one approach to ITS is presented. One of the most important research topics in this field is adaptive cruise control (ACC). The main features of this kind of controller are the adaptation of the speed of the car to a predefined one and the keeping of a safe gap between the controlled car and the preceding vehicle on the road. We present an ACC controller based on fuzzy logic, which assists the speed and distance vehicle control, offering driving strategies and actuation over the throttle of a car. The driving information is supplied by the car tachometer and a RTK differential GPS, and the actuation over the car is made through an electronic interface that simulates the electrical signal of the accelerator pedal directly to the onboard computer. This control is embedded in an automatic driving system installed in two testbed mass-produced cars instrumented for testing the work of these controllers in a real environment. The results obtained in these experiments show a very good performance of the gap controller, which is adaptable to all the speeds and safe gap selections.
Full-text · Article · Oct 2003 · IEEE Transactions on Intelligent Transportation Systems
[Show abstract][Hide abstract] ABSTRACT: This paper presents techniques, related experiments and real results (not simulations) performed with two unmanned vehicles. The test zone is a private circuit with the characteristics of an urban track. The vehicles are common mass-produced cars, provided with automatic actuators operating on the car controls (power-assisted steering and accelerator). These actuators work commanded by a fuzzy logic based control system. The input information to the control system is provided by three elements: high precision GNSS, car tachometer and a wireless network environment.
[Show abstract][Hide abstract] ABSTRACT: This document presents a fuzzy control application in the unmanned
driving field. Two electric cars have been conveniently instrumented in
order to transform them into platforms for automatic driving
experiments. Onboard speed and steering fuzzy controllers are the core
of the guiding system. Navigation is essentially DGPS-based providing
obstacles detection and avoidance by means of artificial vision in a