14 research outputs found
Research on Advanced Control Strategies for Vehicle Active Seat Suspension Systems
Vehicle seat suspensions play a very important role in vibration reduction for vehicle drivers, especially for some heavy vehicles. Compared with small vehicles, these heavy vehicle drivers suffer much more from vibrations, which influence driving comfort and may cause health problems, so seat suspensions are necessary for those heavy vehicle drivers to reduce vibrations and improve driving comfort. Advanced control systems and control strategies are investigated for vehicle seat suspensions in this project. Firstly, for an active single-degree of freedom (single-DOF) seat suspension, a singular system-based approach for active vibration control of vehicle seat suspensions is proposed, where the drivers’ acceleration is augmented into the conventional seat suspension model together with seat suspension deflection and relative velocity as system states to make the suspen- sion model as a singular system. Then, an event-triggered H∞ controller is designed for an active seat suspension, where both the continuous and discrete-time event-triggered schemes are considered, respectively. The proposed control method can reduce the work- load of data transmission of the seat suspension system and work as a filter to remove the effect of noise, so it can decrease the precision requirement of the actuator, which can help to reduce the cost of the seat suspension. For complicated seat suspension systems, a singular active seat suspension system with a human body model is also established and an output-feedback event-triggered H∞ controller is designed. The accelerations of each part are considered as part of the system states, which makes the system a singular sys- tem. The seat suspension deflection, relative velocity, the accelerations of the seat frame, body torso, and head are defined as the system outputs. At last, to deal with whole-body vibration, a control system and a robust H∞ control strategy are designed for a 2-DOF seat suspension system. Two H∞ controllers are designed to reduce vertical and rotational vibrations simultaneously. All the proposed seat suspension systems and control methods are verified by simulations and some are also tested by experiments. These simulation and experimental results show their effectiveness and advantages of the proposed methods to improve the driving comfort and some can reduce the workload of data transmission
Conception et validation d'un contrôleur optimisant la durée de vie et la consommation énergétique d'un actionneur magnétorhéologique
Les actionneurs magnétorhéologiques (MR) à glissement continu utilisent une combinaison d'une ou plusieurs sources de couple (p. ex. un moteur électrique rotatif) et d'un certain nombre d'embrayages magnétorhéologiques configurés en parallèle. Ces embrayages, dont le couple transmis est proportionnel au courant qui leur est fourni, agissent en quelque sorte à titre de filtres mécaniques en permettant un contrôle fin de l'effort transmis, et ce, peu importe l'impédance de la source d'effort. Alors que la plupart des travaux dans la littérature explorent l'impact des choix de conception sur certains indices de performance des actionneurs MR (tel que sa performance dynamique, sa consommation énergétique et la longévité du fluide MR), le présent document vise à explorer l'impact du choix de la stratégie de contrôle. Les travaux présentés dans ce mémoire sont basés sur une étude de cas pour une suspension active de siège de camion. Dans un premier temps, la caractérisation de l'actionneur permet de démontrer ses qualités intrinsèques pour une application de suspension active de siège dont une grande compacité, une grande transparence, une bande passante en force élevée (15 Hz) ainsi qu'une force maximale atteignant 1000 N sur tout le débattement du siège. Dans un deuxième temps, des expériences réalisées en laboratoire et sur route démontrent que cette suspension active peut, pour un profil de route raboteuse, réduire les vibrations transmises au conducteur de 66 % par rapport à une suspension passive pour ainsi respecter les limites d'exposition définies par la norme ISO 2631-1. Enfin, la dernière partie des travaux présentés ici détaille une stratégie de contrôle qui permet de réduire d'environ 20 % la consommation énergétique et d'allonger de 40 % la durée de vie du fluide de l'actionneur pour une utilisation dans un camion roulant sur une route de carrière de pierre
Advanced Mobile Robotics: Volume 3
Mobile robotics is a challenging field with great potential. It covers disciplines including electrical engineering, mechanical engineering, computer science, cognitive science, and social science. It is essential to the design of automated robots, in combination with artificial intelligence, vision, and sensor technologies. Mobile robots are widely used for surveillance, guidance, transportation and entertainment tasks, as well as medical applications. This Special Issue intends to concentrate on recent developments concerning mobile robots and the research surrounding them to enhance studies on the fundamental problems observed in the robots. Various multidisciplinary approaches and integrative contributions including navigation, learning and adaptation, networked system, biologically inspired robots and cognitive methods are welcome contributions to this Special Issue, both from a research and an application perspective
Performance measures and control laws for active and semi-active suspensions
This thesis concentrates on two competing performance requirements of general suspension systems: "smoothness" and tracking. The focus of the thesis is on real-time feedback controls which can be applied in microprocessors with relatively limited capacity. Evolutionary algorithms (EAs) are used as a tool in the investigation of a wide range of control algorithms. Jerk (the rate of change of acceleration) is used as the basis of the suspension comfort performance measure, and a nonlinear cost function is applied to tracking, which targets the travel limits of the suspension (termed the "rattlespace"). Tracking measures currently in use generally fail to explicitly refer to the working space width. This matter is analysed, showing that driver slowdown is a complicating factor. The test rig of the physical experiment is of the semi-active type. High performing semi-active controls are generally based on active controls. Thus active controls are also investigated in this thesis. By stiffening the suspension as it moves away from equilibrium it can be made to combine softness over smooth roads with the capacity to react to large bumps when needed. Electronic control produces a much greater range of possible responses than is possible with just rubber or neoprene bump stops. Electronic, real-time control can attempt to target a smooth chassis trajectory within the possible future limits of rattlespace. Two general methods are proposed and analysed: one that adjusts the suspension stiffening according to the current road state, and another that targets edge trajectories within the possible future movements of the rattlespace. Some of these controls performed very well. With further investigation, they may be developed into extremely high performance controls, especially because of their high adaptability to varying conditions. The problem of avoiding collisions with rattlespace limits is related to the problem of avoiding overshoot of a limit distance. It becomes apparent that the residual acceleration at the point of closest approach needs to be limited, otherwise instability results. This led to the search for controls that attain rest without overshooting the final rest position. It was found that the minimum jerk needed for a general minimum-time control that does not overshoot zero displacement is always the control with just one intermediate switch of control, instead of two switches that are generally needed. This was proven to be optimal, and because of its optimality it works consistently when applied as a closed-loop, real-time optimal control. This control deals with the most difficult part of the trajectory: the final, "docking" manoeuvre. The control proved to be robust in physical experiments and it may itself have a number of applications. Some heuristics have been developed here to account for stochastic movement of the rattlespace edges in suspension controls, and these have proven quite successful in numerical experiments. Semi-active suspensions have a limit on the forces they can apply (the passivity constraint), but clipped versions are known to produce uncomfortable jerk. One method developed in this thesis produces a vast improvement in semi-active controls in the numerical experiments
Investigation of integrated control of articulated heavy vehicle using scaled multi-body dynamic model
Heavy vehicle handling control systems have proven to be an efficient way of reducing road accidents and improving road traffic safety. Testing these control systems on heavy vehicles can be expensive and unsafe. Meanwhile, the scaled model has proven a secure and inexpensive way of designing and deploying vehicle dynamics control. However, the scaled model's mathematical modelling has been mainly limited to the bicycle model, reducing the scope of exploring the handling dynamics. This study presents an innovative way of modelling a scaled tractor semi-trailer using multi-body dynamics software and testing control systems through co-simulation to help develop new control systems safely and inexpensively for improving road traffic safety. In this research, modelling the scaled model of an articulated vehicle was simulated on MSC ADAMS/View, which extends the mathematical model to 168 degrees of freedom. A 1/14 physical model was used to validate the simulation model and co-simulation has been established between MSC ADAMS/View and MATLAB to investigate the control of a scaled model built on MSC ADAMS/View with a developed control system built on MATLAB/Simulink.
The scaled model is a 1/14 Scania R620 articulated lorry manufactured by TAMIYA. Different parameters of the scaled model have been measured and used as inputs to the simulation model. MSC ADAMS/View was used to model the vehicle and to capture its response. The results were validated through physical tests, so a microcontroller was added to the physical model with different accelerometers to control and record the vehicle's motion instead of the existing radio control. Co-simulation has been implemented using two different control schemes, which have been built and compared against each other. The first control scheme is the electronic stability control system only. The second one is an integrated control system which combines the active front steering with the electronic stability control scheme. The main target of the developed control systems is to stabilise the vehicle through manoeuvres using the Fuzzy logic methodology.
The study's main findings are that the experimental results show reasonable similarity to the simulation results, although there are minor differences. The physical validation of the simulation model indicates that it is possible to model a scaled model using multi-body dynamics software with specific considerations. Also, the results give a good understanding of the performance of heavy vehicles. Finally, using the co-simulation implemented using two different control schemes proves that the control can be developed using the scaled model. The proposed control method has been shown to be useful in developing the stability of the vehicle. It enhances the yaw rate for both tractor-trailer by around 25% and the lateral acceleration by around 20% at manoeuvres. Also, the control can be tuned easily using MATLAB. Meanwhile, the electronic stability control scheme gives better performance than the combined active front steering and electronic stability control scheme
Volume 3 – Conference
We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group 8: Pneumatics
Group 9 | 11: Mobile applications
Group 10: Special domains
Group 12: Novel system architectures
Group 13 | 15: Actuators & sensors
Group 14: Safety & reliabilit
Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress
Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018
15th Conference on Dynamical Systems Theory and Applications DSTA 2019 ABSTRACTS
From Preface: This is the fifteen time when the conference „Dynamical Systems – Theory and Applications” gathers a numerous group of outstanding scientists and engineers, who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without a great effort of the staff of the Department of Automation, Biomechanics and Mechatronics. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and the Ministry of Science and Higher Education. It is a great pleasure that our invitation has been accepted by so many people, including good colleagues and friends as well as a large group of researchers and scientists, who decided to
participate in the conference for the first time. With proud and satisfaction we welcome nearly 255 persons from 47 countries all over the world. They decided to share the results of their research and many years experiences in the discipline of dynamical systems by submitting many very interesting papers. This booklet contains a collection of 338 abstracts, which have gained the acceptance of referees and have been qualified for publication in the conference edited books.Technical editor and cover design: Kaźmierczak, MarekCover design: Ogińska, Ewelina; Kaźmierczak, Mare
Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015
This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version