Bicycle Dynamics and Control

In this paper, the dynamics of bicycles is analyzed from the perspective of control. Models of different complexity are presented, starting with simple ones and ending with more realistic models generated from multibody software. Models that capture essential behavior such as self-stabilization as well as models that demonstrate difficulties with rear wheel steering are considered. Experiences using bicycles in control education along with suggestions for fun and thought-provoking experiments with proven student attraction are presented. Finally, bicycles and clinical programs designed for children with disabilities are described

A Linear Parameter-Varying Control Method for Inline Wheel Systems

The design of the bicycle and other single-track systems are continually evolving and have become a key tool for people and goods transportation worldwide [1],[2]. The form factor, carrying capacity, maneuverability, and cost of single-track vehicles makes them advantageous in a variety of circumstances and justifies their use case in the 21st Century [2] [3],[4]. As autonomous double track vehicles arrive on public roads, it is natural that single-track autonomous systems will be developed as well; however, the unstable and non-minimum phase dynamics of single-track vehicles make their control have an additional layer of complexity compared to double track vehicles. Although many researchers have provided commentary on the stability and tracking of a riderless bicycle, relatively few bodies of work have validated their analysis through experimental testing. This work successfully demonstrates that, through gain scheduling, a PID-type controller can balance a riderless single-track vehicle by using a linear actuator to implement front-fork steering control. This control system is novel in the way in which the front fork is actuated. The manual PID tuning process outlined in this body of work is also unique, as well as the specifics of the control law (although PID controllers have been used by other authors). The works of other authors on this topic is briefly summarized and a second-order dynamics system model is derived. Then controller analysis is simulated and then validated experimentally. Suggestions are also made on next steps that can be taken to build upon the work outlined in this thesis.MSEElectrical Engineering, College of Engineering & Computer ScienceUniversity of Michigan-Dearbornhttp://deepblue.lib.umich.edu/bitstream/2027.42/169157/1/Ronald Smith Final Thesis.pd

Bicycles, Motorcycles and Models

Published versio

An Experimental Investigation of Human/Bicycle Dynamics and Rider Skill in Children and Adults.

While humans have been riding bicycles for nearly 200 years, the dynamics of how exactly they achieve this are not well understood. The overall goals of this dissertation were to identify the major control strategies that humans use to balance and steer bicycles, as well as to identify performance metrics that reliably distinguish rider skill level. To achieve these goals, we introduced: a) a novel instrumented bicycle to measure rider control inputs and bicycle response outputs, b) an experimental design and analytical approach for tracking and quantifying rider learning, and c) an experimental design and analytical approaches to measure the dynamics of human/bicycle balance and quantify rider balance performance. We employed variations of the instrumented bicycle in three studies that focused on: 1) how adult riders control bicycle kinematics during steady-state turning, 2) the initial learning of steering and balance control as children learn to ride bicycles, and 3) the balance skill of adult expert and novice riders. The findings from these studies advance our understanding of the types of control used by human riders, and simultaneously, quantify rider learning and skill. During steady-state turning, rider lean strongly influences steering torque, suggesting that rider lean plays an important role in bicycle control. Children learned to ride after successfully learning how to steer in the direction of bicycle roll, thereby increasing the correlation between steer and bicycle roll angular velocities (coefficient of determination increased from 0.22 to 0.75 during the learning process). In adults, the superior balance performance of skilled versus novice riders is revealed by highly correlated lateral positions of the center of pressure and center of mass (coefficients of determination of 0.97 versus 0.89, respectively). In achieving their superior balance performance, skilled riders employed more rider lean control, less steer control, and used less control effort than novice riders. We conclude that rider lean (i.e., any lateral movements of the rider) plays a dominant role in both steering and balancing a bicycle, and that achieving balance requires coordinating both steer and rider lean (the two rider control inputs) with bicycle roll (the bicycle response).PHDBiomedical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/98003/1/smcain_1.pd

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

Eco-Driving planification profile for electric motorcycles

Los perfiles de Eco-Driving son algoritmos capaces de utilizar información adicional para crear recomendaciones o limitaciones sobre las capacidades del conductor. Aumentan la autonomía del vehículo, pero actualmente su uso no está relacionado con la autonomía requerida por el conductor. Por esta razón, en este trabajo, el desafío de la conducción ecológica se traduce en un controlador óptimo de dos capas diseñado para vehículos eléctricos puros. Este controlador está orientado a asegurar que la energía disponible sea suficiente para completar un viaje demandado, agregando límites de velocidad para controlar la tasa de consumo de energía. Se exponen y analizan los modelos mecánicos y eléctricos requeridos. La función de costo está optimizada para corresponder a las necesidades de cada viaje de acuerdo con el comportamiento del conductor, el vehículo y la información de la trayectoria. El controlador óptimo propuesto en este trabajo es un controlador predictivo de modelo no lineal (NMPC) asociado a una optimización unidimensional no lineal. La combinación de ambos algoritmos permite aumentar alrededor de un 50% la autonomía con una limitación del 30% de las capacidades de velocidad y aceleración. Además, el algoritmo es capaz de asegurar una autonomía final con un 1,25% de error en presencia de ruido de sensor y actuador.The Eco-Driving profiles are algorithms capable to use additional information in order to create recommendations or limitation over the driver capabilities. They increase the autonomy of the vehicle but currently its usage is not related to the autonomy required by the driver. For this reason, in this paper, the Eco-Driving challenge is translated into two layers optimal controller designed for pure electric vehicles. This controller is oriented to ensure that the energy available is enough to complete a demanded trip, adding speed limits to control the energy consumption rate. The mechanical and electrical models required are exposed and analyzed. The cost function is optimized to correspond to the needs of each trip according to driver behavior, vehicle and trajectory information. The optimal controller proposed in this paper is a nonlinear model predictive controller (NMPC) associated to a nonlinear unidimensional optimization. The combination of both algorithms lets to increase around 50% the autonomy with a limitation of the 30% of the speed and acceleration capabilities. Also, the algorithm is capable to ensure a final autonomy with a 1.25% of error in the presence of sensor and actuator noise.Doctor en IngenieríaDoctorad

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

Comparison of the vocabularies of the Gregg shorthand dictionary and Horn-Peterson's basic vocabulary of business letters

This study is a comparative analysis of the vocabularies of Horn and Peterson's The Basic Vocabulary of Business Letters1 and the Gregg Shorthand Dictionary.2 Both books purport to present a list of words most frequently encountered by stenographers and students of shorthand. The, Basic Vocabulary of Business Letters, published "in answer to repeated requests for data on the words appearing most frequently in business letters,"3 is a frequency list specific to business writing. Although the book carries the copyright date of 1943, the vocabulary was compiled much earlier. The listings constitute a part of the data used in the preparation of the 10,000 words making up the ranked frequency list compiled by Ernest Horn and staff and published in 1926 under the title of A Basic Writing Vocabulary: 10,000 Words Lost Commonly Used in Writing. The introduction to that publication gives credit to Miss Cora Crowder for the contribution of her Master's study at the University of Minnesota concerning words found in business writing. With additional data from supplementary sources, the complete listing represents twenty-six classes of business, as follows 1. Miscellaneous 2. Florists 3. Automobile manufacturers and sales companie

Sports Medicine and Physical Fitness

Sports Medicine and Physical Fitness has been a successful Special Issue, which addressed novel topics in any subject related to sports medicine, physical fitness, and human movement. The article collection was able to positively evaluate three systematic reviews, nineteen original articles, and one brief report. These encompassed a broad range of topics ranging from accident kinematics, soccer monitoring, children’s physical evaluation, adapted physical activity, physical evaluation for people with intellectual disabilities, performance analysis in rowers, ultramarathon racers, karateka’s, rugby players, volleyball and basketball players, and cross-fit athletes, and also aspects related to biomechanics, fatigue and injury prevention in racing motorcycle riders, gymnasts, and cyclists.These scientific contributions within the field of Sports Medicine and Physical Fitness broaden the understanding of specific aspects of each analyzed discipline.It has been a pleasure for the Editorial Team to have served the International Journal Of Environmental Research and Public Health