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This paper addresses the problem of controlling quarter-vehicle semi-active suspension systems. Presently, the suspension system involves a magnetorheological (MR) damper featuring hysteretic behavior captured through the Bouc-Wen model. The control objective is to regulate well the chassis vertical position despite the road irregularities. The difficulty of the control problem lies in the nonlinearity of the system model, the uncertainty of some parameters and the inaccessibility to measurements of the hysteresis internal state variable. The control design is petformed using Lyapunov control design tools; it includes an observer providing online estimates of the hysteresis internal state and an adaptive state-feedback regulator. The adaptive controller, obtained by combining the state observer and the state-feedback regulator, is formally shown to meet the desired control objectives. This theoretical result is confirmed by several simulations. The latter illustrate the performances of the present adaptive controller and compare them with those of earlier control approaches and those of the passive suspension. [ABSTRACT FROM AUTHOR]

The problem of controlling the longitudinal motion of front-wheels electric vehicle (EV) is considered making the focus on the case where a single dc motor is used for both front wheels. Chassis dynamics are modelled applying relevant fundamental laws taking into account the aerodynamic effects and the road slope variation. The longitudinal slip, resulting from tire deformation, is captured through Kiencke's model. Despite its highly nonlinear nature the complete model proves to be utilizable in longitudinal control design. The control objective is to achieve a satisfactory vehicle speed regulation in acceleration/deceleration stages, despite wind speed and other parameters uncertainty. An adaptive controller is developed using the backstepping design technique. The obtained adaptive controller is shown to meet its objectives in presence of the changing aerodynamics efforts and road slope.

Intussusceptions in adults is rare. Gastrointestinal lipomas are rare benign tumors and intussusceptions due to a gastrointestinal lipoma constitutes an infrequent clinical entity. Lipoma may develop as a benign tumor in all organs and rarely in large or small intestine. The present report describes a case of jejunojejunal intussusceptions in an adult with a history of colicky upper abdominal pain. Ileo-ileal invagination was diagnosed by computed tomography scan. Exploratory laparotomy revealed jejunojejunal intussusceptions secondary to a lipoma which was successfully treated with segmental intestinal resection. A review of the literature is also performed regarding this rare association revealing the diagnostic and therapeutic debates that exist. ABSTRACT (FRENCH): L'invagination chez les adultes est rare. Les lipomes gastro-intestinaux sont de rares tumeurs bénignes et l'invagination intestinale due à un lipome gastro-intestinal constitue une entité clinique trés rare. Le lipome peut se développer comme une tumeur bénigne dans tous les organes et rarement dans l'intestin grêle ou le colon. Le présent rapport décrit un cas d'invagination jéjunojéjunale chez un adulte avec une histoire de douleurs abdominales. Iléo-iléale invagination a été diagnostiquée par tomodensitométrie. Une laparotomie exploratrice a révélé l'existence d'une invagination jéjunojéjunale secondaire à un lipome qui a été traitée avec succès par une résection intestinale segmentaire. Une revue de la littérature est également effectuée au sujet de cette association rare révélant les débats diagnostiques et thérapeutiques qui existent.