Train pneumatic brakes are part of a train safety system, and are thus critical components. This paper illustrates how modeling can be applied to efficiently design such system, from requirement definition to HIL testing. The valves modeling is discussed along with the system level model. Moreover, in order to study the wheel-slide protection device, a model of the wheel-rail interface has been...

In this paper, an original expandable mechanism for unfolding wheels is proposed. This mechanism combines two elementary mechanisms. One allows the deployment of the rim while the other one ensuring the contact shape adaptation. In a first section, we analyse the different deployment mechanisms already proposed in the literature. Then, the design of the rim expansion mechanism is described and ...

Soft soil contact models developed for planetary exploration rovers play an important role in the study of rover mobility. Nowadays, most of the existing contact models are based on Bekker theory which requires the evaluation of several soil parameters usually measured via bevameter tests. However, substantial differences existing between the plate-soil contact scenario and the wheel-soil conta...

Introduction: Allergic and irritant compounds are frequent in nature, and the environmental allergic factors which can induce or exacerbate eczema are different and often unknown in different areas. The aim of this study was to determine the frequency of contact dermatitis in patients with chronic dermatitis referring to dermatology clinics in kerman. Methods: In this descriptive study, standar...

We present 7 cases of postsurgical contact dermatitis due to povidone iodine. The diagnosis was based on the clinical manifestations, the history of exposure, the site of the lesions, and the results of patch tests. This type of dermatitis can develop in the area of surgery or at distant sites exposed to povidone iodine during the surgical intervention. Patch tests with 10% povidone iodine in p...

Methods Demonstrate SNAS which is characterized by contact dermatitis to nickel and systemic reactions after ingestion of rich foods nickel.We evaluated adult patients with ages between 18 and 65 years, positive patch test for nickel, grades 3 and 4, and who had symptoms suggestive of SNAS.These patients had eczematous lesions of contact dermatitis did not disappear. That even with the exclusio...

The geometry of the tracks left by a bicycle has received much attention recently [9, 10, 11, 18, 20, 27]. In this paper we discuss the connection between the motion of a bicycle and that of a curious device known as a hatchet planimeter, and we will prove a conjecture about this planimeter that was made in 1906. Bicycle. We use a very simple model of a bicycle as a moving segment in the plane....

Patch testing is a well-established method of diagnosing contact allergy wherein patients with a history and clinical picture of contact dermatitis are re-exposed to the suspected allergens under controlled conditions to verify the diagnosis [1]. The results of first innovative patch-testing technique were presented by the German dermatologist, Josef Jadassohn (1863-1936) in 1895. The safety an...

In this paper we derive a new dynamic friction force model for the longitudinal road/tire interaction for wheeled ground vehicles. The model is based on a dynamic friction model developed previously for contact-point friction problems, called the LuGre model [1]. By assuming a contact patch between the tire and the ground we develop a partial differential equation for the distribution of the fr...

Mobile robots are increasingly being developed for highrisk missions in rough terrain situations, such as planetary exploration. Here a rough-terrain control (RTC) methodology is presented that exploits the actuator redundancy found in multi-wheeled mobile robot systems to improve ground traction and reduce power consumption. The methodology “chooses” an optimization criterion based on the loca...