5 research outputs found
Dynamic neural network-based feedback linearization of electrohydraulic suspension systems
Resolving the trade-offs between suspension travel, ride comfort, road holding,
vehicle handling and power consumptions is the primary challenge in designing
Active-Vehicle-Suspension-Systems (AVSS). Controller tuning with global
optimization techniques is proposed to realise the best compromise between these
con
icting criteria. Optimization methods adapted include
Controlled-Random-Search (CRS), Differential-Evolution (DE), Genetic-Algorithm
(GA), Particle-Swarm-Optimization (PSO) and Pattern-Search (PS). Quarter-car
and full-car nonlinear AVSS models that incorporate electrohydraulic actuator
dynamics are designed. Two control schemes are proposed for this investigation.
The first is the conventional Proportional-Integral-Derivative (PID) control, which
is applied in a multi-loop architecture to stabilise the actuator and manipulate the
primary control variables. Global optimization-based tuning achieved enhanced
responses in each aspect of PID-based AVSS performance and a better resolve in
con
icting criteria, with DE performing the best. The full-car PID-based AVSS
was analysed for DE as well as modi ed variants of the PSO and CRS. These
modified methods surpassed its predecessors with a better performance index and
this was anticipated as they were augmented to permit for e cient exploration of
the search space with enhanced
exibility in the algorithms. However, DE still
maintained the best outcome in this aspect. The second method is indirect
adaptive dynamic-neural-network-based-feedback-linearization (DNNFBL), where
neural networks were trained with optimization algorithms and later feedback
linearization control was applied to it. PSO generated the most desirable results,
followed by DE. The remaining approaches exhibited signi cantly weaker results
for this control method. Such outcomes were accredited to the nature of the DE
and PSO algorithms and their superior search characteristics as well as the nature
of the problem, which now had more variables. The adaptive nature and ability to
cancel system nonlinearities saw the full-car PSO-based DNNFBL controller
outperform its PID counterpart. It achieved a better resolve between performance
criteria, minimal chatter, superior parameter sensitivity, and improved suspension
travel, roll acceleration and control force response
Optimized state feedback regulation of 3DOF helicopter system via extremum seeking
In this paper, an optimized state feedback regulation of a 3 degree of freedom (DOF) helicopter is designed via extremum seeking (ES) technique. Multi-parameter ES is applied to optimize the tracking performance via tuning State Vector Feedback with Integration of the Control Error (SVFBICE).
Discrete multivariable version of ES is developed to minimize a cost function that measures the performance of the controller. The cost function is a function of the error between the actual and desired axis positions. The controller parameters are updated online as the optimization takes place. This method significantly decreases the time in obtaining optimal controller parameters. Simulations were conducted for the online optimization under both fixed and varying operating conditions. The results demonstrate the usefulness of using ES for preserving the maximum attainable performance
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