18 research outputs found
Integral high order sliding mode control of a brake system
The aim of this paper is to present the design of a robust sliding mode control scheme for a vehicle system which consists of active brake systems. The proposed control strategy is based on the combination of high order sliding mode control methods and integral sliding mode control, taking advantage of the block control principle. The brake controller induces the antilock brake system feature by means of tracking the slip rate of the car, improving the stability in the braking process and preventing the vehicle from skidding.Cinvesta
A Modified HOSM Controller Applied to an ABS Laboratory Setup with Adaptive Parameter
The antilock braking system (ABS) is an electromechanical device whose controller is challenging to design because of its nonlinear dynamics and parameter uncertainties. In this paper, an adaptive controller is considered under the assumption that the friction coefficient is unknown. A modified high-order sliding-mode controller is designed to enhance the controller performance. The controller ensures tracking of the desired reference and identifies the unknown parameter, despite parametric variations acting on the real system. The stability proof is done using the Lyapunov approach. Some numerical and experimental tests evaluate the controller on a mechatronic system that represents a quarter-car model
MAREJADAS RURALES Y LUCHA POR LA VIDA, VOL. I:CONSTRUCCIÓN SOCIOCULTURAL Y ECONÓMICA DEL CAMPO.
Este volumen incluye trabajos que abordan temáticas
que demuestran que el campo es una construcción sociocultural, por lo tanto,
el medio rural es diferenciado y está en constante cambio y adaptación a los
procesos globales y locales.
Son 19 trabajos divididos en dos secciones, la primera, denominada Nuevas
dinámicas sociales, económicas y culturales en el medio rural, está compuesta
por 8 capítulos, en esta sección se incluyen aquellos trabajos que analizan de
manera concreta los cambios perceptibles en las relaciones rurales y en las
actividades económicas; procesos como desagrarización y nuevas actividades
económicas son abordados aquí, así como propuestas metodológicas para el
estudio de lo rural considerando los cambios y adaptaciones que se registran
en los territorios.
La segunda sección, Resistencias y alternativas al modelo neoliberal en la
producción agrícola y alimentaria, está integrada por 11 trabajos que abordan
las diversas formas en que los campesinos y productores agrícolas resisten y
se adaptan a los cambios globales y a las modificaciones de política pública,
desde los mercados alternativos hasta la producción de nuevos cultivos que
generan un mercado nuevo a su producción, hasta las resistencias y defensa de
la milpa, las reflexiones que nos ofrecen dan idea de la diversidad de formas
en que la vida campesina se mantiene a pesar de todos los embates.INSTITUTO DE CIENCIAS AGROPECUARIAS Y RURALES (ICAR), UNIVERSIDAD DE GUADALAJARA, EL COLEGIO DE MICHOACÁN A.C., CUCOSTA SUR GRANA, FACULTAD DE ESTUDIOS SUPERIORES ACATLÁN-UNAM, ECOSU
Mis casos clínicos de especialidades odontológicas
Libro que muestra la atención de casos clínicos particulares referente a las diferentes especialidades odontológicasLibro que muestra la atención de casos clínicos particulares referente a las diferentes especialidades odontológicasUniversidad Autónoma de Campeche
Universidad Autónoma del Estado de Hidalgo
Universidad Autónoma del Estado de Méxic
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
High order integral nested sliding mode control
This paper exposes a controller for the nonlinear systems in the block controllable form. This proposal guarantees exponential exact tracking in the presence of unknown matched and unmatched disturbances by means a combination of the block control method and integral terms designed with high-order sliding-modes algorithms. Both, matched and unmatched, disturbances are compensated by those integral continuous terms and the tracking is achieved with the design of a nominal control la
HOSM Controller Using PI Sliding Manifold for an Integrated Active Control for Wheeled Vehicles
This study considers the design of a modified high-order sliding mode (HOSM) controller using a PI sliding surface to the attitude control of a ground vehicle. A robust-modified HOSM controller is derived, so that the lateral velocity and yaw rate tracks the desired trajectory despite the environment actions acting on the ground vehicle and parameter variations. The stability is guaranteed with Lyapunov’s stability theorem function. The performance of the dynamic controllers is evaluated using the CarSim simulator considering a challenging double steer maneuver
A Lyapunov Stability Analysis of Modified HOSM Controllers Using a PID-Sliding Surface Applied to an ABS Laboratory Setup
The antilock braking system (ABS) is a mechatronic system that helps a driver maintain the maneuverability of a vehicle while braking by preventing wheel lock-ups. However, the design of high-performance controllers for this type of system is complicated because of its highly nonlinear dynamics. The problem becomes even more difficult to resolve when uncertainties in the parameters appear in its dynamics. In this paper, an ABS laboratory setup mimicking a quarter car model is considered. A modified high-order sliding mode (HOSM) controller using a proportional-integral-differential (PID) control as a sliding surface was designed. This controller provides a reference value of a tire slip. The proposed controller uses a tracking error to define the slip surface through the PID controller structure, and the modified HOSM controller holds the system on the previously designed slip surface. The closed-loop system stability has been proven in the sense of Lyapunov. Finally, the ABS laboratory setup allows for experimentally checking the performance of the modified HOSM controller using a PID-sliding surface, showing a considerable increase in the efficiency of the control system compared with a PID-like controller
A Lyapunov Stability Analysis of Modified HOSM Controllers Using a PID-Sliding Surface Applied to an ABS Laboratory Setup
The antilock braking system (ABS) is a mechatronic system that helps a driver maintain the maneuverability of a vehicle while braking by preventing wheel lock-ups. However, the design of high-performance controllers for this type of system is complicated because of its highly nonlinear dynamics. The problem becomes even more difficult to resolve when uncertainties in the parameters appear in its dynamics. In this paper, an ABS laboratory setup mimicking a quarter car model is considered. A modified high-order sliding mode (HOSM) controller using a proportional-integral-differential (PID) control as a sliding surface was designed. This controller provides a reference value of a tire slip. The proposed controller uses a tracking error to define the slip surface through the PID controller structure, and the modified HOSM controller holds the system on the previously designed slip surface. The closed-loop system stability has been proven in the sense of Lyapunov. Finally, the ABS laboratory setup allows for experimentally checking the performance of the modified HOSM controller using a PID-sliding surface, showing a considerable increase in the efficiency of the control system compared with a PID-like controller