Control of two-steering-wheels vehicles with the Transverse Function approach

The control of a wheeled vehicle with front and rear steering wheels is addressed. With respect to more classical car-like vehicles, an advantage of this type of mechanism is its enhanced manoeuvrability. The Transverse Function approach is used to derive feedback laws which ensure practical stabilization of arbitrary reference trajectories in the Cartesian space, and asymptotic stabilization when the trajectory is feasible by the nonholonomic vehicle. Concerning this latter issue, previous results are extended to the case of transverse functions defined on the Special Orthogonal Group SO(3).Ce rapport concerne la commande de véhicules dont les deux trains, avant et arrière, sont directeurs. L'avantage de ce type de mécanisme par rapport à des systèmes plus classiques, de type voiture par exemple, réside dans sa meilleure maneuvrabilité. L'approche de commande par fonctions transverses est ici utilisée pour synthétiser des commandes par retour d'état qui assurent d'une part la stabilité pratique de trajectoires de référence arbitraires dans l'espace cartésien, et d'autre part la stabilité asymptotique lorsque ces trajectoires sont réalisables par le véhicule non-holonome. En ce qui concerne ce dernier aspect, des résultats antérieurs sont ici étendus à une classe de commandes définies sur le groupe spécial orthogonal SO(3)

Modelling commercial vehicle handling and rolling stability

YesThis paper presents a multi-degrees-of-freedom non-linear multibody dynamic model of a three-axle heavy commercial vehicle tractor unit, comprising a subchassis, front and rear leaf spring suspensions, steering system, and ten wheels/tyres, with a semi-trailer comprising two axles and eight wheels/tyres. The investigation is mainly concerned with the rollover stability of the articulated vehicle. The models incorporate all sources of compliance, stiffness, and damping, all with non-linear characteristics, and are constructed and simulated using automatic dynamic analysis of mechanical systems formulation. A constant radius turn test and a single lane change test (according to the ISO Standard) are simulated. The constant radius turn test shows the understeer behaviour of the vehicle, and the single lane change manoeuvre was conducted to show the transient behaviour of the vehicle. Non-stable roll and yaw behaviour of the vehicle is predicted at test speeds .90 km/h. Rollover stability of the vehicle is also investigated using a constant radius turn test with increasing speed. The articulated laden vehicle model predicted increased understeer behaviour, due to higher load acting on the wheels of the middle and rear axles of the tractor and the influence of the semi-trailer, as shown by the reduced yaw rate and the steering angle variation during the constant radius turn. The rollover test predicted a critical lateral acceleration value where complete rollover occurs. Unstable behaviour of the articulated vehicle is also predicted in the single lane change manoeuvre

Design of a pressurized lunar rover

A pressurized lunar rover is necessary for future long-term habitation of the moon. The rover must be able to safely perform many tasks, ranging from transportation and reconnaissance to exploration and rescue missions. Numerous designs were considered in an effort to maintain a low overall mass and good mobility characteristics. The configuration adopted consists of two cylindrical pressure hulls passively connected by a pressurized flexible passageway. The vehicle has an overall length of 11 meters and a total mass of seven metric tons. The rover is driven by eight independently powered two meter diameter wheels. The dual-cylinder concept allows a combination of articulated frame and double Ackermann steering for executing turns. In an emergency, the individual drive motors allow the option of skid steering as well. Two wheels are connected to either side of each cylinder through a pinned bar which allows constant ground contact. Together, these systems allow the rover to easily meet its mobility requirements. A dynamic isotope power system (DIPS), in conjunction with a closed Brayton cycle, supplied the rover with a continuous supply of 8.5 kW. The occupants are all protected from the DIPS system's radiation by a shield of tantalum. The large amount of heat produced by the DIPS and other rover systems is rejected by thermal radiators. The thermal radiators and solar collectors are located on the top of the rear cylinder. The solar collectors are used to recharge batteries for peak power periods. The rover's shell is made of graphite-epoxy coated with multi-layer insulation (MLI). The graphite-epoxy provides strength while the thermally resistant MLI gives protection from the lunar environment. An elastomer separates the two materials to compensate for the thermal mismatch. The communications system allows for communication with the lunar base with an option for direct communication with earth via a lunar satellite link. The various links are combined into one signal broadcast in the S-band at 2.3 GHz. The rover is fitted with a parabolic reflector disk for S-band transmission, and an omnidirectional antenna for local extravehicular activity (EVA) communication. The rover's guidance, navigation, and control subsystem consists of an inertial guidance system, an orbiting lunar satellite, and an obstacle avoidance system. In addition, the rover is equipped with a number of external fixtures including two telerobotic arms, lights, cameras, EVA storage, manlocks, a docking fixture, solar panels, thermal radiators, and a scientific airlock. In conclusion, this rover meets all of the design requirements and clearly surpasses them in the areas of mobility and maneuverability

Improving of transitway operating properties

Modern public transport systems are increasingly seen as an important means of promoting the safe mobility of the population, especially in urban areas suffering from growing traffic jams. The Transitway or the new bus system “Bus Rapid Transport” (BRT) is the result of the development of a bus public transport network. In comparison with the subway, this project has obvious advantages: lower cost of network creation, lower cost of rolling stock, mobility, etc. These advantages are manifested, first of all, with the maximum use of passenger capacity of transitways, that is, with the application of three-axles transitways and with their motion on the maximum possible speeds. The purpose of this paper is to present the findings of the transitway motion stability research, which was based on the analysis of solutions of motion differential equations. These equations were compiled with respect to the variables of the longitudinal and transverse velocities of the center of the bus mass and the angular velocities of the bus and of two couplings. As a result of the research, the critical velocity of the three-axles transitway has been determined and factors influencing its numerical value have been analyzed. It has been shown that during the operation of the transitway it is necessary to maintain such pressure in the tires so that, for the selected load on the wheels of the axes of the auto-train, the coefficient of resistance to the lateral separation of the wheels of the steered wheels of the bus and the trailer is smaller than the wheels of uncontrolled axes. The practical value of the research is that this finding will be used for increasing the critical speed vcr of the auto-train

Behavior-based Fuzzy Control For A Mobile Robot With Non-holonomic Constraints

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2005Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2005Bu çalışmada robotik alanında yeni yaklaşımlar olan davranış temelli robotik ve bulanık mantık konuları gerçek zamanda mobil robot uygulamaları bakımından incelenmiş, dört ilerlemeli, dört yönelmeli bir mobil robot için Engelden Sakın , Hedefe Git , Duvarı İzle , Yola Teğet İlerle , Avare Gez davranışları oluşturulmuştur. Bu davranışların içinden Engelden Sakın , Hedefe Git ve Duvarı İzle davranışları için sonar sensör matematik modelleri oluşturulmuş ve bu davranışların yapısında bulanık mantık yaklaşımı kullanılmıştır. Mobil robot, kinetik ve dinamik olarak holonomik olmayan kısıtları kullanılarak modellenmiştir ve simülasyon sırasında mobil robotun pozisyonu, tekerlek ve robot yönelimleri, tekerlek ve robot hızları, tekerlek torkları gibi parametreler izlenebilmektedir. Davranışlar da, simülasyon ortamında kazanımları, bulanık mantık işleme yapıları, gerçek zaman uygulanabilirliği ve davranışların koordine edilmeleri bakımından incelenmiştir. Bu çalışma gerçek bir robotta yapılacak deneyler için temel teşkil etmektedir.In this study, the new approaches to the robotics subject, behavior-based robotics and fuzzy logic control are investigated for the real-time applications of mobile robots, Avoid Obstacle , Move to Goal , Wall Following , Head-on , Wander behaviors are built up for a four-wheel driven and four-wheel steered mobile robot. Sonar sensor mathematical models are formed for Avoid Obstacle , Move to Goal and Wall Following behaviors and fuzzy logic concepts are used in the structure of these behaviors. The mobile robot is modelled kinematically and dynamically considering the non-holonomic constraints. The posture and speed of the robot and the configurations, speeds and torques of the wheels can be obtained from the simulation. The behaviors are investigated regarding their gains, fuzzy inference structures, real-time applicabilities and thein coordination. This study constitutes basis for the experiments on a real mobile robot.Yüksek LisansM.Sc

Phase 1 of the near term hybrid passenger vehicle development program. Appendix B: Trade-off studies, volume 1

Tradeoff study activities and the analysis process used are described with emphasis on (1) review of the alternatives; (2) vehicle architecture; and (3) evaluation of the propulsion system alternatives; interim results are presented for the basic hybrid vehicle characterization; vehicle scheme development; propulsion system power and transmission ratios; vehicle weight; energy consumption and emissions; performance; production costs; reliability, availability and maintainability; life cycle costs, and operational quality. The final vehicle conceptual design is examined

Performance and Safety Enhancement Strategies in Vehicle Dynamics and Ground Contact

Recent trends in vehicle engineering are testament to the great efforts that scientists and industries have made to seek solutions to enhance both the performance and safety of vehicular systems. This Special Issue aims to contribute to the study of modern vehicle dynamics, attracting recent experimental and in-simulation advances that are the basis for current technological growth and future mobility. The area involves research, studies, and projects derived from vehicle dynamics that aim to enhance vehicle performance in terms of handling, comfort, and adherence, and to examine safety optimization in the emerging contexts of smart, connected, and autonomous driving.This Special Issue focuses on new findings in the following topics:(1) Experimental and modelling activities that aim to investigate interaction phenomena from the macroscale, analyzing vehicle data, to the microscale, accounting for local contact mechanics; (2) Control strategies focused on vehicle performance enhancement, in terms of handling/grip, comfort and safety for passengers, motorsports, and future mobility scenarios; (3) Innovative technologies to improve the safety and performance of the vehicle and its subsystems; (4) Identification of vehicle and tire/wheel model parameters and status with innovative methodologies and algorithms; (5) Implementation of real-time software, logics, and models in onboard architectures and driving simulators; (6) Studies and analyses oriented toward the correlation among the factors affecting vehicle performance and safety; (7) Application use cases in road and off-road vehicles, e-bikes, motorcycles, buses, trucks, etc

English. Навчальний посібник з англійської мови для студентів І-ІІ курсів спеціальності «Автомобілі і автомобільне господарство»

Part I… Lesson 1. Essential parts of an automobile… 5-- Unit 2. Types of Waves…8 -- Unit 3. Speed of Waves… 10-- Unit 4. Interactions of Waves…13-- Unit 5. Electromagnetic Waves…16-- Unit 6. Type of Waves…19-- Part II…22-- Unit 1. Infrared Rays… 22-- Unit 2. Visible Light…25-- Unit 3. Wave or Particle?... 29-- Unit 4. Reflection of Light…31-- Unit 5. Reflection and Mirrors…34-- Unit 6. Refraction of Light…37-- Unit 7. Optical Instruments…40-- Unit 8. Lasers…43-- Unit 9. Fiber Optics… 47-- Part III… 52-- Unit 1. A Halogen Lamp…52-- Unit 2. LED Lamp…54-- Unit 3. Electroluminescent Wire… 57-- Unit 4. Black Light… 59-- Unit 5. Compact Fluorescent Lamp (CFL)… 62-- Unit 6. Plasma Lamps. …65-- Unit 7. Architectural Lighting Design…68-- Part IV…70-- Additional reading… 70-

Maniobrabilidad de vehículos de competición

[ES] El siguiente proyecto aborda de forma detallada la dinamica vehicular de coches de competicion y como afecta esta a la maniobrabilidad. La dinamica es uno de los aspectos mas importantes a tener en cuenta para el diseño de vehiculos de produccion, y mas aun, debido a la naturaleza competitiva y el alto ritmo de evolucion, en los vehiculos de competicion. Se comienza desarrollando un estudio sobre el comportamiento de los neumaticos, analizando las fuerzas que actuan sobre ellos y las distintas variables a tener en cuenta. A continuacion, nos encontramos con un capitulo en el que se explica la propia dinamica del vehiculo al completo, analizando las respuestas del vehiculo en estado estacionario y en estado transitorio. El siguiente capitulo trata sobre el frenado, en el que se indagan las formulas fundamentales para su entendimiento y algunos de los sistemas que se utilizan en la alta competicion. Siguiendo con la tematica, el apartado cinco es un estudio sobre la direccion y las geometrias utilizadas para optimizar el rendimiento. Para finalizar, se estudian las tecnicas de conduccion y los posibles reglajes que ayudan a bajar el tiempo por vuelta.[EN] The following project deals in detail with the vehicle dynamics of racing cars and how it affects handling. Dynamics is one of the most important aspects to be taken into account in the design of production vehicles, and even more so, due to the competitive nature and the high rate of evolution, in racing vehicles. We begin by developing a study on the behaviour of tyres, analysing the forces acting on them and the different variables to be taken into account. This is followed by a chapter in which the dynamics of the vehicle itself is explained in full, analysing the responses of the vehicle in steady and transient states. The next chapter deals with braking, in which the fundamental formulas for its understanding and some of the systems used in high competition are investigated. Continuing the theme, section five is a study of steering and the geometries used to optimise performance. Finally, driving techniques and possible settings to help lower lap times are examined