modeling and simulation of the motorcycle s lowside fall

Abstract The deployment of active safety systems enhancing the motorcycle stability and supporting riders in defusing critical and dangerous driving situations is a topic of major concern in the two-wheel research community. In the design and development of safety control systems, setting up an adequate model of the controlled system is a key issue since it should be able to describe adequately the motion of the vehicle in critical situations such as precarious adherence, cornering brake and acceleration, or dangerous falls. In literature, these situations are typically investigated by means of black box approaches, namely by using multibody numerical simulators in which the equations governing the vehicle dynamics are unknown. In this paper, instead, the authors propose an analytical model as alternative to black box approach for the simulation of critical and complex motorcycle's dynamics leading to falls. The model has been presented in author's earlier works, it has a minimum degree of complexity, considers the rear wheel traction/braking and takes into account the interactions between longitudinal and lateral friction forces acting on the tyres. This analytical model has allowed to investigate the lowside phenomenon and the simulation results will be presented

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

All wheel drive electric motorcycle modelling and control.

Conventional motorcycles are powered through a chain or shaft linking the engine to the rear wheel. However, motorcycle riders are now facing riding conditions and obstacles where having only rear wheel drive can lead to vehicle damage, loss of control and an unstable front wheel during cornering and off-road riding in general. Traction and climbing ability are severely limited in extreme mountain conditions by only having the rear wheel to provide power. Accordingly, there is a need in the industry for a two-wheel drive motorcycle that efficiently and safely transfers power from the motor to the front wheel, because it provides the rider with increased ability to safely negotiate rough terrain. In this background, the design of an optimal torque distribution strategy implemented by two separate electric motors in an all-wheel-drive electric motorcycle has many potentialities not fully explored and deeply understood for two wheel vehicles, that makes this study interesting from a scientific point of view. With this in mind, the research project aims to design control systems for improving rider’s safety and vehicle performance at low as well as high speeds, especially in critical situations and rough terrains, taking into account the presence of the front wheel torque generated by a hub-mounted electric motor. At low speed the research investigates whether and how the front wheel torque helps the stabilization of the vehicle around the upright position, without any rider action required. The study is developed by deriving a simplified analytical model of the vehicle, which captures its lateral motion and a model-based control system, employing the sliding mode control technique. As further requirement, the motorcycle should be balanced in a small bounded area, by means of Multi Input control system. At medium and high speeds the study explores how and how much the traction torque repartition can improve continuously the vehicle performances in combined longitudinal and lateral acceleration situations, such as the exit of a curve, especially in those conditions where a traditional motorcycle falls down because it overcomes tyre adherence limits. Last purpose is achieved deriving a dynamical optimal traction strategy which does not require the a priori knowledge of the friction coefficient. Steady state analysis indicates outperformances of the all wheel drive motorcycle over the classical rear wheel drive one. Then, dynamical simulations of selected manoeuvres, in both flat and uneven road, corroborate the result

Advances in Mechanical Systems Dynamics 2020

The fundamentals of mechanical system dynamics were established before the beginning of the industrial era. The 18th century was a very important time for science and was characterized by the development of classical mechanics. This development progressed in the 19th century, and new, important applications related to industrialization were found and studied. The development of computers in the 20th century revolutionized mechanical system dynamics owing to the development of numerical simulation. We are now in the presence of the fourth industrial revolution. Mechanical systems are increasingly integrated with electrical, fluidic, and electronic systems, and the industrial environment has become characterized by the cyber-physical systems of industry 4.0. Within this framework, the status-of-the-art has become represented by integrated mechanical systems and supported by accurate dynamic models able to predict their dynamic behavior. Therefore, mechanical systems dynamics will play a central role in forthcoming years. This Special Issue aims to disseminate the latest research findings and ideas in the field of mechanical systems dynamics, with particular emphasis on novel trends and applications

Minimum-lap-time optimisation and simulation

The paper begins with a survey of advances in state-of-the-art minimum-time simulation for road vehicles. The techniques covered include both quasi-steady-state and transient vehicle models, which are combined with trajectories that are either pre-assigned or free to be optimised. The fundamentals of nonlinear optimal control are summarised. These fundamentals are the basis of most of the vehicular optimal control methodologies and solution procedures reported in the literature. The key features of three-dimensional road modelling, vehicle positioning and vehicle modelling are also summarised with a focus on recent developments. Both cars and motorcycles are considered

Stability issues in racing motorcycles: an in-depth analysis of the chatter vibration

Racing motorcycles are prone to an unstable oscillatory motion of the swingarm and rear wheel, commonly known as ‘chatter’. This vibration mode typically has a frequency of 17 Hz to 22 Hz and typically occurs during heavy braking manoeuvres. The appearance of chatter can cause reduced rider confidence, and therefore lead to longer lap times during races and the increased risk of crashing. This thesis looks to further the understanding of this mode. It includes the development of a simplified model to explore the effects roll angle and lateral dynamics have on the chatter mode using linear analysis. The mechanisms of instability and parameter sensitivities are also examined. The effects of the nonlinearities present in the minimal model equations of motion are examined, including the identification of limit cycles and their stability, inspecting individual nonlinear terms and their effects, and introducing tyre relaxation and determining the effect it has on the dynamics. Finally, an exploratory study of the mid-corner region of a typical racing manoeuvre is performed in hopes to better understand if any high frequency tyre induced instabilities like chatter can occur

Force sensors for active safety, stability enhancement and lightweight construction of road vehicles

Force and moment measurement at different locations within road vehicles is a multifaceted, comprehensive and forthcoming technology that might play a breakthrough role in automotive engineering. The paper aims to describe why such technology seems so promising. A literature review is accomplished on which forces can be measured and what can be obtained with force and moment data. Additionally, attention is devoted to where–and how–force and moments can be measured effectively. Force and moment measurement technology is also studied with an historical perspective, briefly analysing the past applications. Active safety systems (ADAS up to full automated driving) and automotive stability enhancement systems are expected to be impacted by the measurement of forces and moments at the wheels. Friction potential evaluation and driver model development and monitoring have been–and are expected to be–major field of research. Force and moment measurement technology may also be exploited for lightweight construction purposes with remarkable synergistic effects with active safety and stability enhancement systems. Possible innovations on lightweight construction and sustainable mobility are to be expected thanks to force and moment measurement

Influences of drive torque distribution on road vehicle handling and efficiency

With recent developments in active vehicle drivelines and the trend towards the use of electric propulsion in road vehicles, the optimal way to distribute power in a vehicle has become an interesting area of research. Automobiles with Active Torque Distribution (ATD) capabilities demonstrate improved handling and stability, and there is the possibility that energy consumption could be reduced through better distribution of power. Motorcycles that can apply some of the drive torque at the front wheel exist, with the aim of increasing tractive force on low-friction surfaces. Research is required to investigate the effects of torque distribution on the handling and efficiency of motorcycles and automobiles. In this work, multibody models of both motorcycles and automobiles are created, and are verified with existing mathematical models. The vehicle models include the influences of suspension, aerodynamics and gyroscopic effects, and complex tyre models are used that account for combined lateral and longitudinal slip and the vertical loading situation. Simple driver models are used to control the speed and yaw rate of the vehicles while they undertake a series of on-road manoeuvres. Left–right torque vectoring is shown to be effective in the alteration of the steady-state handling characteristics of the automobile, and front–rear torque vectoring has a small effect at high speeds. A slight increase is possible in transient responsiveness at moderate speeds, but instabilities can be exacerbated at high speeds. In motorcycles, the torque distribution has only a small effect on handling in steady-state situations. During straight-running, the optimum efficiency of the both vehicles is shown to occur when the torque is distributed in proportion with the vertical load at the tyres. During cornering, a slight additional bias towards the front wheel(s) is beneficial. Despite the alteration in handling characteristics made available through ATD, the effects of weight distribution and tyre characteristics still dominate. At normal speeds, almost the same effect on automobile handling can be achieved through left–right torque vectoring in a front- or rear-wheel-drive vehicle, as in a four-wheel-drive vehicle. In these steady-state situations, the energy efficiency of the vehicles varies only by small amounts, with aerodynamic and lateral slip dissipations dominating. The models presented in this thesis, and the results and conclusions obtained from them, offer the designers of future vehicles useful information for the improvement of vehicle handling, efficiency and quality

Identification of the mechanical properties of tires for wheelchair simulation.

The development of high performance wheelchairs and wheelchair simulators requires dynamic models taking into account the properties of tires. In this paper the properties of two wheelchair tires are measured by means of a rotating disc testing machine and are compared with the properties of bicycle tires, which have similar dimensions and structure. Tests are carried out considering variations in speed, inflation pressure and load. The possibility of fitting experimental results with the Magic Formula, the Dugoff formula and a linear model is discussed. A dynamic model of a wheelchair is developed, which includes a linear tire model derived from experimental results. Steady turning and slalom manoeuvres are simulated. Numerical results show the effect of tire properties on the handling characteristics of the wheelchair.N/

Influences of drive torque distribution on road vehicle handling and efficiency

With recent developments in active vehicle drivelines and the trend towards the use of electric propulsion in road vehicles, the optimal way to distribute power in a vehicle has become an interesting area of research. Automobiles with Active Torque Distribution (ATD) capabilities demonstrate improved handling and stability, and there is the possibility that energy consumption could be reduced through better distribution of power. Motorcycles that can apply some of the drive torque at the front wheel exist, with the aim of increasing tractive force on low-friction surfaces. Research is required to investigate the effects of torque distribution on the handling and efficiency of motorcycles and automobiles. In this work, multibody models of both motorcycles and automobiles are created, and are verified with existing mathematical models. The vehicle models include the influences of suspension, aerodynamics and gyroscopic effects, and complex tyre models are used that account for combined lateral and longitudinal slip and the vertical loading situation. Simple driver models are used to control the speed and yaw rate of the vehicles while they undertake a series of on-road manoeuvres. Left–right torque vectoring is shown to be effective in the alteration of the steady-state handling characteristics of the automobile, and front–rear torque vectoring has a small effect at high speeds. A slight increase is possible in transient responsiveness at moderate speeds, but instabilities can be exacerbated at high speeds. In motorcycles, the torque distribution has only a small effect on handling in steady-state situations. During straight-running, the optimum efficiency of the both vehicles is shown to occur when the torque is distributed in proportion with the vertical load at the tyres. During cornering, a slight additional bias towards the front wheel(s) is beneficial. Despite the alteration in handling characteristics made available through ATD, the effects of weight distribution and tyre characteristics still dominate. At normal speeds, almost the same effect on automobile handling can be achieved through left–right torque vectoring in a front- or rear-wheel-drive vehicle, as in a four-wheel-drive vehicle. In these steady-state situations, the energy efficiency of the vehicles varies only by small amounts, with aerodynamic and lateral slip dissipations dominating. The models presented in this thesis, and the results and conclusions obtained from them, offer the designers of future vehicles useful information for the improvement of vehicle handling, efficiency and quality