Torque vectoring based drive assistance system for turning an electric narrow tilting vehicle

The increasing number of cars leads to traffic congestion and limits parking issue in urban area. The narrow tilting vehicles therefore can potentially become the next generation of city cars due to its narrow width. However, due to the difficulty in leaning a narrow tilting vehicle, a drive assistance strategy is required to maintain its roll stability during a turn. This article presents an effective approach using torque vectoring method to assist the rider in balancing the narrow tilting vehicles, thus reducing the counter-steering requirements. The proposed approach is designed as the combination of two torque controllers: steer angle–based torque vectoring controller and tilting compensator–based torque vectoring controller. The steer angle–based torque vectoring controller reduces the counter-steering process via adjusting the vectoring torque based on the steering angle from the rider. Meanwhile, the tilting compensator–based torque vectoring controller develops the steer angle–based torque vectoring with an additional tilting compensator to help balancing the leaning behaviour of narrow tilting vehicles. Numerical simulations with a number of case studies have been carried out to verify the performance of designed controllers. The results imply that the counter-steering process can be eliminated and the roll stability performance can be improved with the usage of the presented approach

Direct and Steering Tilt Robust Control of Narrow Vehicles

International audienceNarrow Tilting Vehicles (NTVs) are the convergence of a car and a motorcycle. They are expected to be the new generation of city cars considering their practical dimensions and lower energy consumption. However, due to their height to breadth ratio, in order to maintain lateral stability, NTVs should tilt when cornering. Unlike the motorcycle, where the driver tilts the vehicle himself, the tilting of an NTV should be automatic. Two tilting systems are available; Direct and Steering Tilt Control, the combined action of these two systems being certainly the key to improve considerably NTV dynamic performances. In this paper, multivariable control tools (H2 methodology) are used to design, in a systematic way, lateral assistance controllers driving DTC, STC or both DTC/STC systems. A three degrees of freedom model of the vehicle is used, as well as a model of the steering signal, leading to a two degrees of freedom low order controller with an efficient feedforward anticipative part. Taking advantage of all the available measurements on NTVs, the lateral acceleration is directly regulated. Finally, a gain-scheduling solution is provided to make the DTC, STC, and DTC/STC controllers robust to longitudinal speed variations

Narrow Urban Vehicles with an Integrated Suspension Tilting System: Design, Modeling, and Control

Narrow urban vehicles are proposed to alleviate urban transportation challenges like congestion, parking, fuel consumption, and pollution. They are designed to seat one or two people in tandem, which saves space in road infrastructures as well as improves the fuel efficiency. However, to overcome the high rollover tendency which comes as a consequence of reduced track-width ratio, tilting systems for vehicle roll motion control are suggested. Existing tilting solutions, which mechanically connect the wheel modules on both sides for motion synchronization, are not space-friendly for the narrow vehicle footprint. The mechanical linkages also add extra weight to those urban vehicles initially designed to be light-weighted. A novel integrated suspension tilting system (ISTS) is proposed in this thesis, which replaces rigid mechanical linkages with flexible hydraulic pipes and cylinders. In addition, combining the suspension and tilting into an integrated system will result in even more compact, light-weighted, and spacious urban vehicles. The concept is examined, and the suspension mechanism for the tilting application is proposed after examining various mechanisms for their complexity and space requirements. Kinematic and dynamic properties of the tilting vehicle under large suspension strokes are analyzed to optimize the mechanism design. Control of the active tilting systems for vehicle roll stability improvement is then discussed. Rather than tilting the vehicle to entirely eliminate the lateral load transfer during cornering, an integrated envelope approach considering both lateral and roll motion is proposed to improve the energy efficiency while maintaining the vehicle stability. A re-configurable integrated control structure is also developed for various vehicle configurations as well as enhancing the system robustness against actuator failures. The model predictive control (MPC) scheme is adopted considering the non-minimum phase nature of active tilting systems. The predictive feature along with the proposed roll envelope formulation provides a framework to balance the transient and steady-state performances using the tilting actuators. The suggested controller is firstly demonstrated on a vehicle roll model, and then applied to high-fidelity full vehicle models in CarSim including a four-wheeled SUV as well as a three-wheeled narrow urban vehicle. The SUV simulation results indicate the potential of using the developed envelope controller on conventional vehicles with active suspensions, while the narrow urban vehicle simulations demonstrate the feasibility of using the suggested ISTS on narrow tilting vehicles. By adopting the integrated envelope control approach, actuation effort is reduced and the vehicle handling, along with the stability in both lateral and roll, can be further improved

V/STOL aircraft configurations and opportunities in the Pacific Basin

Advanced aircraft configurations offer new transportation options for the Pacific Basin. Described is a range of vehicles from low-disk to high-disk loading aircraft, including high-speed rotorcraft, subsonic vertical and short takeoff and landing (V/STOL) aircraft, and subsonic short takeoff and landing (STOL) aircraft. The status and advantages of the various configurations are described. Some of these show promise for satisfying many of the transportation requirements of the Pacific Basin; as such, they could revolutionize short-haul transportation in that region

Modelling and simulations of a narrow track tilting vehicle

Narrow track tilting vehicle is a new category of vehicle that combines the dynamical abilities of a passenger car with a motorcycle. In the presence of overturning moments during cornering, an accurate assessment of the lateral dynamics plays an important role to improve their stability and handling. In order to stabilise or control the narrow tilting vehicle, the demand tilt angle can be calculated from the vehicle’s lateral acceleration and controlled by either steering input of the vehicle or using additional titling actuator to reach this desired angle. The aim of this article is to present a new approach for developing the lateral dynamics model of a narrow track tilting vehicle. First, this approach utilises the well-known geometry ‘bicycle model’ and parameter estimation methods. Second, by using a tuning method, the unknown and uncertainties are taken into account and regulated through an optimisation procedure to minimise the model biases in order to improve the modelling accuracy. Therefore, the optimised model can be used as a platform to develop the vehicle control strategy. Numerical simulations have been performed in a comparison with the experimental data to validate the model accuracy

Modelling and simulations of a narrow track tilting vehicle

Narrow track tilting vehicle is a new category of vehicle that combines the dynamical abilities of a passenger car with a motorcycle. In the presence of overturning moments during cornering, an accurate assessment of the lateral dynamics plays an important role to improve their stability and handling. In order to stabilise or control the narrow tilting vehicle, the demand tilt angle can be calculated from the vehicle’s lateral acceleration and controlled by either steering input of the vehicle or using additional titling actuator to reach this desired angle. The aim of this article is to present a new approach for developing the lateral dynamics model of a narrow track tilting vehicle. First, this approach utilises the well-known geometry ‘bicycle model’ and parameter estimation methods. Second, by using a tuning method, the unknown and uncertainties are taken into account and regulated through an optimisation procedure to minimise the model biases in order to improve the modelling accuracy. Therefore, the optimised model can be used as a platform to develop the vehicle control strategy. Numerical simulations have been performed in a comparison with the experimental data to validate the model accuracy

Study of aircraft in intraurban transportation systems, volume 1

An analysis of an effective short range, high density computer transportation system for intraurban systems is presented. The seven county Detroit, Michigan, metropolitan area, was chosen as the scenario for the analysis. The study consisted of an analysis and forecast of the Detroit market through 1985, a parametric analysis of appropriate short haul aircraft concepts and associated ground systems, and a preliminary overall economic analysis of a simplified total system designed to evaluate the candidate vehicles and select the most promising VTOL and STOL aircraft. Data are also included on the impact of advanced technology on the system, the sensitivity of mission performance to changes in aircraft characteristics and system operations, and identification of key problem areas that may be improved by additional research. The approach, logic, and computer models used are adaptable to other intraurban or interurban areas

Community rotorcraft air transportation benefits and opportunities

Information about rotorcraft that will assist community planners in assessing and planning for the use of rotorcraft transportation in their communities is provided. Information useful to helicopter researchers, manufacturers, and operators concerning helicopter opportunities and benefits is also given. Three primary topics are discussed: the current status and future projections of rotorcraft technology, and the comparison of that technology with other transportation vehicles; the community benefits of promising rotorcraft transportation opportunities; and the integration and interfacing considerations between rotorcraft and other transportation vehicles. Helicopter applications in a number of business and public service fields are examined in various geographical settings

NASA's aeronautics program: Systems technology and experimental program

The appropriateness of the division of effort between the directed to the solution of near-term problems and that directed to long-term technical advances in the program is addressed. Comparisons between in-house work and out-of-house work are presented. Programs include those in: general aviation; propulsive lift; rotorcraft; avionics and flight controls; small transport aircraft; and human/vehicle systems