1,488 research outputs found
Dynamic Analysis of Vehicle Performance for Changes to Rear Axle Housing
This paper explores the performance improvements of a 2013 Ford Mustang Shelby GT500 resulting from changes to the rear axle housing. In previous work, described in [1, 2], the rear axle housing was optimized in order to minimize its weight. It was expected that the decrease in weight would lead to improved fuel economy; in this work, the vehicle was simulated for the EPA highway drive cycle (HWFET) both before and after the optimization of the housing, in order to quantify the changes in fuel economy. It was found that the optimization of the housing did produce a modest improvement in the chassis energy demand and in the fuel energy demand
Sizing of an Electric Power Steering system on dynamic and energetic criteria
International audienceThis paper presents the methodology to size a mechatronic system on dynamic and energetic criteria. The methodology is based on the establishment of the inverse model from the bond graph representation of the system by using the bicausality concept. By means of an automotive example, we illustrate the methodology and we present a solution to extend it to more complex problem
Advanced Control and Estimation Concepts, and New Hardware Topologies for Future Mobility
According to the National Research Council, the use of embedded systems throughout society could well overtake previous milestones in the information revolution. Mechatronics is the synergistic combination of electronic, mechanical engineering, controls, software and systems engineering in the design of processes and products. Mechatronic systems put “intelligence” into physical systems. Embedded sensors/actuators/processors are integral parts of mechatronic systems. The implementation of mechatronic systems is consistently on the rise. However, manufacturers are working hard to reduce the implementation cost of these systems while trying avoid compromising product quality. One way of addressing these conflicting objectives is through new automatic control methods, virtual sensing/estimation, and new innovative hardware topologies
New Approaches in Automation and Robotics
The book New Approaches in Automation and Robotics offers in 22 chapters a collection of recent developments in automation, robotics as well as control theory. It is dedicated to researchers in science and industry, students, and practicing engineers, who wish to update and enhance their knowledge on modern methods and innovative applications. The authors and editor of this book wish to motivate people, especially under-graduate students, to get involved with the interesting field of robotics and mechatronics. We hope that the ideas and concepts presented in this book are useful for your own work and could contribute to problem solving in similar applications as well. It is clear, however, that the wide area of automation and robotics can only be highlighted at several spots but not completely covered by a single book
Advance control strategies for Maglev suspension systems
The Birmingham Maglev developed over fifteen years ago has successfully demonstrated
the inherent advantages of low speed maglev over comparable wheeled systems. It
remains the only commercially operational Maglev in the world today. To develop the
next generation of Maglev vehicles which will overcome some of the limitations of the
Birmingham system, such as chassis length and cost, the following issues are addressed
in this thesis.
1) The possibility of interaction between the chassis resonant frequencies and the
suspension control system causing poor ride quality and at worst instability, are
formally analysed. In the Birmingham vehicle a stiff chassis (fundamental bending
mode 40Hz) is used avoiding significant interaction with the suspension controller.
Using advanced control strategies the low frequency chassis resonances can be
controlled allowing a vehicle structure to be used with a fundamental bending
mode of about 12Hz.
2) A modem control strategy is developed which delivers an improved ride quality
compared with the present classical control system despite having to operate with
a 'soft' chassis. Kalman filters are digitally implemented and conclusions drawn
about their performance. The classical control strategy is also successfully
demonstrated on a 3 m long 'flexible beam' rig.
3) An associated Maglev suspension problem for the response to ramp inputs such
as the transition onto gradients which causes either a large steady state tracking
error or a worsening ride quality is addressed by modern control theory using
integral feedback techniques and classical theory using third order filters. These
controllers are globally optimised by a multi-objective parameter optimisation
system which formally considers the conflicts inherent in a suspension system
between response to stochastic inputs and deterministic inputs
Single chip solution for stabilization control & monocular visual servoing of small-scale quadrotor helicopter
This thesis documents the research undertaken to develop a high-performing design
of a small-scale quadrotor (four-rotor) helicopter capable of delivering the speed and
robustness required for agile motion while also featuring an autonomous visual servoing
capability within the size, weight, and power (SWaP) constraint package. The
state of the art research was reviewed, and the areas in the existing design methodologies
that can potentially be improved were identified, which included development
of a comprehensive dynamics model of quadrotor, design and construction of a performance
optimized prototype vehicle, high-performance actuator design, design of a
robust attitude stabilization controller, and a single chip solution for autonomous vision
based position control. The gaps in the current art of designing each component
were addressed individually. The outcomes of the corresponding development activities
include a high-fidelity dynamics and control model of the vehicle. The model
was developed using multi-body bond graph modeling approach to incorporate the
dynamic interactions between the frame body and propulsion system. Using an algorithmic
size, payload capacity, and flight endurance optimization approach, a quadrotor
prototype was designed and constructed. In order to conform to the optimized
geometric and performance parameters, the frame of the prototype was constructed
using printed circuit board (PCB) technology and processing power was integrated
using a single chip field programmable gate array (FPGA) technology. Furthermore, to actuate the quadrotor at a high update rate while also improving the power efficiency
of the actuation system, a ground up FPGA based brushless direct current
(BLDC) motor driver was designed using a low-loss commutation scheme and hall
effect sensors. A proportional-integral-derivative (PID) technology based closed loop
motor speed controller was also implemented in the same FPGA hardware for precise
speed control of the motors. In addition, a novel control law was formulated for robust
attitude stabilization by adopting a cascaded architecture of active disturbance rejection
control (ADRC) technology and PID control technology. Using the same single
FPGA chip to drive an on-board downward looking camera, a monocular visual servoing
solution was developed to integrate an autonomous position control feature with
the quadrotor. Accordingly, a numerically simple relative position estimation technique
was implemented in FPGA hardware that relies on a passive landmark/target
for 3-D position estimation.
The functionality and effectiveness of the synthesized design were evaluated by
performance benchmarking experiments conducted on each individual component as
well as on the complete system constructed from these components. It was observed
that the proposed small-scale quadrotor, even though just 43 cm in diameter, can lift
434 gm of payload while operating for 18 min. Among the ground up designed components,
the FPGA based motor driver demonstrated a maximum of 4% improvement in
the power consumption and at the same time can handle a command update at a rate
of 16 kHz. The cascaded attitude stabilization controller can asymptotically stabilize
the vehicle within 426 ms of the command update. Robust control performance under
stochastic wind gusts is also observed from the stabilization controller. Finally, the
single chip FPGA based monocular visual servoing solution can estimate pose information
at the camera rate of 37 fps and accordingly the quadrotor can autonomously
climb/descend and/or hover over a passive target
Proceedings of the International Micro Air Vehicles Conference and Flight Competition 2017 (IMAV 2017)
The IMAV 2017 conference has been held at ISAE-SUPAERO, Toulouse, France from Sept. 18 to Sept. 21, 2017. More than 250 participants coming from 30 different countries worldwide have presented their latest research activities in the field of drones. 38 papers have been presented during the conference including various topics such as Aerodynamics, Aeroacoustics, Propulsion, Autopilots, Sensors, Communication systems, Mission planning techniques, Artificial Intelligence, Human-machine cooperation as applied to drones
Unified modelling of aerospace systems: a bond graph approach
Systems Integration is widely accepted as the basis for improving the efficiency and performance of many engineering products. The aim is to build a unified optimised system not a collection of subsystems that are combined in some ad hoc manner. This moves traditional design boundaries and, in so doing, enables a structured evolution from an integrated system concept to an integrated system product.
It is recognised that the inherent complexity cannot be handled effectively without mathematical modelling. The problem is not so much the large number of components but rather the very large number of functional interfaces that result. The costs involved are high and, if the claims of improved efficiency and performance are to be affordable (or even achievable), predictive modelling and analysis will play a major role in reducing risk.
A modelling framework is required which can support integrated system development from concept through to certification. This means building a 'system' inside a computer and demonstrating the feasibility of an entire development cycle. The objective is to provide complete coverage of system functionality so as to gain confidence in the design before becoming locked into a full development programme with associated capital investment and contractual arrangements.
With these points in mind the purpose of this thesis is threefold. First, to demonstrate the application of bond graphs as a unified modelling framework for aerospace systems. Second, to review the main principles involved with the modelling of engineering systems and to justify the selection of the bond graph notation as a suitable means of representing the power flow (i.e. the dynamics) of physical systems. Third, to present an exposition of the bond graph method and to evolve it into a versatile notation for integrated systems.
The originality of the work is based on the recognition that systems integration is a relatively new field of interest without a mature body of academic literature or reported research. Apparently, there is no open literature on the modelling of complete air vehicles plus their embedded vehicle systems which deals with issues of integrated dynamics and control. To this end, bond graph concepts need to be developed and extended in new direction in order to facilitate an intuitive approach to the modelling of integrated systems
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