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

Stabilizing control design of a motorcycle

This thesis solves the stabilizing control of an autonomous motorcycle. The control of an autonomous motorcycle is a challenging and interesting problem in the field because the plant is under-actuated, unstable and nonlinear. Two major problems that have not been considered in the literature are explicitly solved in our work: (i) the robust control problem of the plant subject to uncertainty and exogenous disturbance; (ii) the non-local stabilization of the nonlinear plant. To achieve the first goal, we propose a robust H_infty controller based on the linearized system, which provides a significant improvement in dealing model uncertainty and disturbance attenuation in comparison with those controllers given by classical linear design tools. To achieve the second goal, we propose a nonlinear controller based on the combination of a nonlinear forwarding method with several other methods for the nonlinear plant through identifying an appropriate upper triangular structure of the nonlinear system. This yields a stability region, the whole upper space above the level ground, such that the trajectory starting from any position in the upper hemi-sphere with arbitrary initial velocities converges to the upright position. Both results are novel and first results of their kinds in control of an autonomous motorcycle. Computer simulations verify the effectiveness of the proposed controllers

Quadrotor multibody modelling by vehiclesim: adaptive technique for oscillations in a PVA control system

The work presented here covers the detailed modelling and trajectory control for an elastic bladed quadrotor vehicle. The benefits of using VehicleSim modelling software are also discussed. The authors present a full elastic structural and dynamical model as well as two different aerodynamic models. These two aerodynamic models differ from each other on their level of complexity and therefore, accuracy. The control methodology employed to stabilize and guide the vehicle is PVA (ProportionalVelocity-Acceleration), derived and implemented by using Simulink. As it will be shown, it stabilises and provides satisfactory quadrotor trajectory tracking. Since the control methodology feeds back the acceleration of the vehicle, and this acceleration has an oscillating nature, an adaptive process has been designed and introduced into the vehicle’s model in order to avoid the oscillations’ transmission to the control system, showing how it reduces the amplitude of the control actions oscillations. Results of simulations and discussion on them are also provided at the end of this article

Cyclist 360° Alert: Validation of an Instrumented Bicycle Trajectory Reconstruction Mechanism Using Satellite and Inertial Navigation Systems

Cycling is an increasingly popular mode of travel in cities owing to the great advantages that it offers in terms of space consumption, health and environmental sustainability. However, the number of recent accidents between cyclists and heavy goods vehicles has increased substantially. Our study shows that one of the main causes of accidents is drivers not being able to observe cyclists. Thus, this research reported here involves the development of an innovative low-cost technological solution called Cyclist 360° Alert and as an integral part of this system, this paper focuses on the bicycle localization aspect and presents an approach based on low-cost micro-electromechanical systems (MEMS) sensor con figurations on an instrumented prototype bicycle system, called “iBike”. The iBike has the capability of sensing its motion, which can be then analysed to compute the trajectory path. The paper describes the overall system of the instrumented bicycle which incorporates an Inertial Navigation System (INS) and a Global Navigation Satellite System (GNSS) receiver. The paper then evaluates and compare the accuracy of the three positioning systems using experimental field data. Finally, the paper also draws conclusions on the applicability of specific sensor configurations, both in terms of sensors’ accuracy and reliability with respect to the measurements of motion, and the ability of tracking trajectories based on the data gathered from the sensor

An Innovative Multi-Sensor Fusion Algorithm to Enhance Positioning Accuracy of an Instrumented Bicycle

Cycling is an increasingly popular mode of travel in cities, but its poor safety record currently acts as a hurdle to its wider adoption as a real alternative to the private car. A particular source of hazard appears to originate from the interaction of cyclists with motorized traffic at low speeds in urban areas. But while technological advances in recent years have resulted in numerous attempts at systems for preventing cyclist-vehicle collisions, these have generally encountered the challenge of accurate cyclist localization. This paper addresses this challenge by introducing an innovative bicycle localization algorithm, which is derived from the geometrical relationships and kinematics of bicycles. The algorithm relies on the measurement of a set of kinematic variables (such as yaw, roll, and steering angles) through low-cost on-board sensors. It then employs a set of Kalman filters to predict-correct the direction and position of the bicycle and fuse the measurements in order to improve positioning accuracy. The capabilities of the algorithm are then demonstrated through a real-world field experiment using an instrumented bicycle, called ``iBike'', in an urban environment. The results show that the proposed fusion achieves considerably lower positioning errors than that would be achieved based on dead-reckoning alone, which makes the algorithm a credible basis for the development of future collision warning and avoidance systems

Robust stabilization of running self-sustaining two-wheeled vehicle

金沢大学理工研究域電子情報学系This paper deals with robust stabilization of running self-sustaining two-wheeled vehicle. Recently, some researches about stabilization of two-wheeled vehicle have been reported. These researches have achieved the stabilization running only by the steering control. However, an actual two-wheeled vehicle is running while accompanying stabilization by the rider. We have proposed the stabilization of two-wheeled vehicle in the state of stillness, and have shown the effectiveness. In this research, we compose the control system that aims at the running stabilization of two-wheeled vehicle. We use ℋ∞ mixed sensitivity problem to design the controller to achieve stability running even if the mass of two-wheeled vehicle changes. The experimental results show stability running even if the mass of two-wheeled vehicle changed. © 2007 IEEE

Path Following and Stabilization of an Autonomous Bicycle

In this thesis we investigate the problem of designing a control system for a modern bicycle so that the bicycle is stable and follows a path. We propose a multi-loop control architecture, where each loop is systematically designed using linear control techniques. The proposed strategy guarantees that the bicycle asymptotically converges to paths of constant curvature. A key advantage of our approach is that by using linear techniques analysis and controller design are relatively simple. We base our control design on the nonlinear (corrected) Whipple model, which has been previously verified for correctness and experimentally validated. The equations of motion for the nonlinear model are very complicated, and would take many pages to explicitly state. They also have no known closed form solution. To enable analysis of the model we linearize it about a trajectory such that the bicycle is upright and travelling straight ahead. This linearization allows us to arrive at a parameterized linear time-invariant state-space representation of the bicycle dynamics, suitable for analysis and control design. The inner-loop control consists of a forward-speed controller as well as a lean and steer controller. To keep the bicycle at a constant forward speed, we develop a high-bandwidth proportional controller that uses a torque along the axis of the rear wheel of the bicycle to keep the angular velocity of the rear wheel at a constant setpoint. To stabilize the bicycle at this forward speed, lean torque and steer torque are treated as the control signals. We design a state-feedback controller and augment integrators to the output feedback of the lean angle and steer angle to provide perfect steady-state tracking. To arrive at the gains for state feedback, linear-quadratic regulator methods are used. When following a constant-curvature path, a vehicle has a constant yaw rate. Using this knowledge, we begin designing the outer-loop path-following control by finding a map that converts a yaw rate into appropriate lean angle and steer angle references for the inner loop. After the map is completed, system identification is performed by applying a yaw-rate reference to the map and analyzing the response of the bicycle. Using the linear approximation obtained, a classical feedback controller for yaw-rate tracking is designed. In addition to yaw-rate control, to track a path the yaw angle of the bicycle must match that of the path and the bicycle must physically be on the path. To analyze these conditions a linear approximation for the distance between the bicycle to the path is found, enabling construction of a linear approximation of the entire system. We then find that by passing the signal for the difference in yaw rate and the distance through separate controllers, summing their output, and subtracting from the reference yaw rate of the path, the bicycle converges to the path. After developing the general design procedure, the final part of the thesis shows a step by step design example and demonstrates the results of applying the proposed control architecture to the nonlinear bicycle model. We highlight some problems that can arise when the bicycle is started far from the path. To overcome these problems we develop the concept of a virtual path, which is a path that when followed returns the bicycle to the actual path. We also recognize that, in practice, typical paths do not have constant curvature, so we construct more practical paths by joining straight line segments and circular arc segments, representing a practical path similar to a path that would be encountered when biking through a series of rural roads. Finally, we finish the design example by demonstrating the performance of the control architecture on such a path. From these simulations we show that using the suggested controller design that the bicycle will converge to a constant curvature path. Additionally with using the controllers we develop that in the absence of disturbance the bicycle will stay within the intended traffic lane when travelling on a typical rural road