[Show abstract][Hide abstract] ABSTRACT: Four longitudinal control techniques are compared: a classical Proportional-Integral (PI) control; an advanced technique-called the i-PI-that adds an intelligent component to the PI; a fuzzy controller based on human experience; and an adaptive-network-based fuzzy inference system. The controllers were designed to tackle one of the challenging topics as yet unsolved by the automotive sector: managing autonomously a gasoline-propelled vehicle at very low speeds. The dynamics involved are highly nonlinear and constitute an excellent test-bed for newly designed controllers. A Citroën C3 Pluriel car was modified to permit autonomous action on the accelerator and the brake pedals-i.e., longitudinal control. The controllers were tested in two stages. First, the vehicle was modeled to check the controllers' feasibility. Second, the controllers were then implemented in the Citroën, and their behavior under the same conditions on an identical real circuit was compared.
IEEE Transactions on Industrial Electronics 02/2012; · 6.50 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this work was twofold: on the one hand, to describe a comparative study of two intelligent control techniques—fuzzy and intelligent proportional-integral (PI) control, and on the other, to try to provide an answer to an as yet unsolved topic in the automotive sector—stop-and-go control in urban environments at very low speeds. Commercial vehicles exhibit nonlinear behavior and therefore constitute an excellent platform on which to check the controllers. This paper describes the design, tuning, and evaluation of the controllers performing actions on the longitudinal control of a car—the throttle and brake pedals—to accomplish stop-and-go manoeuvres. They are tested in two steps. First, a simulation model is used to design and tune the controllers, and second, these controllers are implemented in the commercial vehicle—which has automatic driving capabilities—to check their behavior. A stop-and-go manoeuvre is implemented with the two control techniques using two cooperating vehicles.
IEEE Transactions on Control Systems Technology 01/2012; · 2.00 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Day by day the number of vehicles on roads is growing, increasing also the number of accidents, traffic jams and carbon dioxide emissions. For this reason, the European Union has adopted an action plan for improving urban mobility where the public transport is the main key. To present day, solutions as special bus lanes, electrical and hydrogen buses and rail-guided buses have been tested and implemented in several cities as London and Madrid. In this article an automated stopping system for electrical buses is presented. Stopping system have been implemented by the AUTOPIA program on an electric minibus and tested on a private circuit with satisfactory results.
Compatibility and Power Electronics (CPE), 2011 7th International Conference-Workshop; 07/2011
[Show abstract][Hide abstract] ABSTRACT: This article presents a cooperative manoeuvre among three dual mode cars – vehicles equipped with sensors and actuators, and that can be driven either manually or autonomously. One vehicle is driven autonomously and the other two are driven manually. The main objective is to test two decision algorithms for priority conflict resolution at intersections so that a vehicle autonomously driven can take their own decision about crossing an intersection mingling with manually driven cars without the need for infrastructure modifications. To do this, the system needs the position, speeds, and turning intentions of the rest of the cars involved in the manoeuvre. This information is acquired via communications, but other methods are also viable, such as artificial vision. The idea of the experiments was to adjust the speed of the manually driven vehicles to force a situation where all three vehicles arrive at an intersection at the same time.
Transportation Research Part C: Emerging Technologies. 01/2011; 19(6):1095-1110.
[Show abstract][Hide abstract] ABSTRACT: This article presents a cartographic system to facilitate cooperative manoeuvres among autonomous vehicles in a well-known environment. The main objective is to design an extended cartographic system to help in the navigation of autonomous vehicles. This system has to allow the vehicles not only to access the reference points needed for navigation, but also noticeable information such as the location and type of traffic signals, the proximity to a crossing, the streets en route, etc. To do this, a hierarchical representation of the information has been chosen, where the information has been stored in two levels. The lower level contains the archives with the Universal Traverse Mercator (UTM) coordinates of the points that define the reference segments to follow. The upper level contains a directed graph with the relational database in which streets, crossings, roundabouts and other points of interest are represented. Using this new system it is possible to know when the vehicle approaches a crossing, what other paths arrive at that crossing, and, should there be other vehicles circulating on those paths and arriving at the crossing, which one has the highest priority. The data obtained from the cartographic system is used by the autonomous vehicles for cooperative manoeuvres.
Journal of Navigation 01/2011; 64(1):141-155. · 0.62 Impact Factor
[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.
Intelligent Transportation Systems (ITSC), 2010 13th International IEEE Conference on; 10/2010
[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.
Intelligent Transportation Systems (ITSC), 2010 13th International IEEE Conference on; 10/2010
[Show abstract][Hide abstract] ABSTRACT: This paper presents a comparison of Stop & Go control algorithms, which deal with car following scenarios in urban environments. Since many vehicle/road interaction factors (road slope, aerodynamic forces) and actuator dynamics are very poorly known, two robust control strategies are proposed: an intelligent PID controller and a fuzzy controller. Both model-free techniques will be implemented and compared in simulation to show their suitability for demanding scenarios.
Intelligent Transportation Systems (ITSC), 2010 13th International IEEE Conference on; 10/2010
[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: 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.
IEEE Transactions on Intelligent Transportation Systems 04/2010; · 3.06 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This paper deals with autonomous vehicles. This could be considered a utopian goal nowadays but recent advances bring it closer than ever. Automation of the actuators involved in the management of a car, and control of the steering wheel constitute two of the most complex issues involved. We here describe an automatic power steering architecture to manage the steering wheel via an Ethernet controller. An on-board PC is connected to the controller to permit handling by computer generated signals. An electric car has been equipped with the system, and we present the results of tests of the behaviour of the system in real situations on the private driving circuit at the IAI facilities.
[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.
International Journal of Automotive Technology 01/2010; 11(1):89-95. · 0.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The significant increment in the number of advanced driver assistance systems (ADAS) in mass-produced cars suggest the idea of autonomous or semi-autonomous vehicles driving in roads in a medium-large term. Consequently, a system to allow the communication among this kind of vehicles and manual driven vehicles will have to be used in order to permit the circulation of both of them at the same time. Two communication modes have to be taken into account. First, a vehicle-to-vehicle communication (V2V) to permit the traffic data flow among cars. Second, a vehicle-to-infrastructure communication (V2I) to allow a central station to coordinate the movements of the vehicle in case of a failure in the V2V. In this paper we present an architecture capable of operating either in autonomous vehicles or manual driven vehicles and coordinating their movements based on a V2I communication. Two mass-produced vehicles are used in order to test the behavior of the architecture implementation. Experimental trials to study the response of the system and the information flow have been carried out.
[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.
RIAI - Revista Iberoamericana de Automatica e Informatica Industrial. 10/2009; 6(4):61-68.
[Show abstract][Hide abstract] ABSTRACT: Computer systems to carry out control algorithms on autonomous vehicles have been developed in recent years. However, the advances in peripheral devices allow connecting the actuator controllers to the control system by means of standard communication links (USB, CAN, Ethernet...). The goal is to permit the use of standard computers. In this paper, we present the evolution of AUTOPIA architecture and its modularity and adaptability to move the old system based on ISA controller cards to a new system with Ethernet and CAN connected controllers. The results show a comparison between both systems and the improved performance of the new system.
Mechatronics, 2009. ICM 2009. IEEE International Conference on; 05/2009
[Show abstract][Hide abstract] ABSTRACT: Driverless driving is one of the most interesting topics in the field of the intelligent transportation systems. Among these topics, the automation of the actuators involved in the management of a car, and out of them the control of the steering wheel constitute one of the most complex. In this paper, automatic power steering architecture to manage the steering wheel via Ethernet controller is developed. An on-board PC is connected to the controller to permit handling by computer generated signals. An electric car has been equipped with the system designed and tests to prove the behavior of the system in actual situations in the private driving circuit at the IAI facilities are included.
[Show abstract][Hide abstract] ABSTRACT: The goal that a car be driven autonomously is far in the future and probably unreachable, but as a first step in that direction, adaptive cruise control (ACC) and Stop&Go maneuver systems are being developed. These kind of controllers adapt the speed of a car to that of the preceding one (ACC) and get the car to stop if the lead car stops. This paper presents one such system and related experiments performed on a real road with real cars. The driving system gets its input via an RTK DGPS device and communicates its positions to one another via a wireless local area network link. It outputs signals controlling the pressure on the throttle and brake pedals. The control system is based on fuzzy logic, which is considered best to deal with processes as complex as driving. Two mass produced Citroen Berlingo electric vans have been instrumented, providing them with computer controlled actuators over the brake and the throttle to achieve human-like driving. The results of the experiments show that the behavior of the vehicles is very close to human and that they adapt to driving incidences, increasing the safety of the driving and permitting cooperation with manually driven cars.
IEEE Transactions on Vehicular Technology 08/2007; · 2.06 Impact Factor
[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
Intelligent Transportation Systems Conference, 2006. ITSC '06. IEEE; 10/2006
[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.