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• ##### Speed Variation along an Imposed Linear Trajectory, for Robotic Arms Motion
495-502
Views:
77

The paper describes a method of speed (velocity) computation, named mixt profile, during a motion upon an imposed linear trajectory. The method assures an accurate positioning at the end of motion (movement), in a well determinate time lapse. The described method is linked with position vector computation, about a robotic arm.

• ##### Displacement: Translation and Rotation. Differences and Similarities in the Discrete and Continuous Models
104-124
Views:
138

The motion (displacement) of the Euclidean space can be decomposed into translation and rotation. The two kinds of motion of the Euclidean space based on two structures of the Euclidean space: The first one is the topological structure, the second one is the idea of distance. The motion is such a (topological) map, that the distance of any two points remains the same. The bounded and closed domain of the Euclidean space is taken as a model of the rigid body. The bounded and closed domain of the Euclidean space is also taken as a model of the deformable solid body. The map – i.e. the displacement field – of the deformable solid body is continuous, but is not (necessarily) motion; the size and the shape of body can change. The material has atomic-molecular structure. In compliance with it, the material can be comprehended as a discrete system. In this case the elements of the material, as an atom, molecule, grain, can be comprehended as either material point, or rigid body. In the first case the kinematical freedom is the translation, in the latter case the translation and the rotation. In the paper we analyse how the kinematical behaviour of the discrete and continuous mechanical system can be characterise by translation and rotation. In the discrete system the two motions are independent variable. At the same time they characterise the movement of the body different way. For instance homogeneous local translation gives the global translation, but the homogeneous local rotation does not give the global rotation. To realise global rotation in a discrete system on one hand global rotation of the position of the discrete elements, on the other hand homogeneous local rotations of the discrete elements in harmony with global rotation are required. In the continuous system the two kinds of movement cannot be interpreted: a point cannot rotate, a rotation of surrounding of a point or direction can be interpreted. The kinematical characteristics, as the displacement (practically this is equal to translation) of (neighbourhood of) point, the rotation of surrounding of that point and the rotation of a direction went through that point are not independent variables: the translation of a point determines the rotation of the surrounding of that point as well as the rotation of a direction went through that point. With accordance this statement the displacement (practically translation) (field) as the only kinematical variable can be interpreted in the continuous medium.

• ##### Flexibility Analysis Of Inventory Cost Model With Ergonomics
166-173
Views:
133

The economic and environmental sustainability issues in supply chain management have integrated by many researchers in the past decades. The ergonomics as a social aspect of sustainability had received a little attention by researchers. Therefore, the aim of the paper is analyzing the flexibility of developed inventory cost model with relaxation allowance and endurance time as a social aspect of sustainability. The effects of distance, unit weight of item and total number of items on relaxation allowance, the total cost of logistics operation and the EOQ model were investigated. The analyzed mathematical model was a single operator-single material model which covered transportation of fixed amount of raw materials from storage plant to production plant by manual material handling with simple cart and picking, storing, pushing and pushing back with empty cart for manual handling of the products. The different parameter values applied for analysis such as total amount of handled items (Q) changes between 500 pcs to 2750 pcs, unit weight of item (w) changes between 0.1 kg to 1 kg, distance of movement by manual material handling for picking and storing motions (d1) changes between 2 m to 3 m and the distance between the storing equipment and the supermarket of the production line for pushing motion (d2) changes between 15 m to 20 m. The results of the analysis indicated that the longer the distance of movement for all motions leads to decrease in savings of the model compared to EOQ model. The increase in unit weight of item is increase the savings obtained from application of our model and decrease the optimal lot size. There was no specific change on savings or optimal lot size as the total amount of handled item is increase. The compared results indicated that an increase in d1 and d2 lead to an increase in optimal lot size and increase in total cost of the model. Consequently, the analysis has shown that a decrease in lot size would be the better way to improve both ergonomic conditions and total cost of production in any different parameter values. Finally, the analysis of the inventory model with ergonomics were proved that this model is suitable for different industrial practices.

• ##### Examining the Movement Differences in the Behavior of Normal and Rack Railway Vehicle
96-103
Views:
273

The rack railway is a special type of railroad. There weren”t much built worldwide, and their number is decreasing. Now, in Budapest, there is a possibility to create an interoperable vehicle, based upon the experience gained from the previously operated line, and all the research regarding its unique characteristics. One from the many important sector of its operation, is the rail/rack/vehicle system. Its mechanical model is far more complex than a traditional railroad vehicle. We will demonstrate its behaviorial differences from a traditional railroad vehicle.

• ##### Vehicle Dynamics Simulation in Matlab/Simulink Environment
36-41
Views:
275

In the following we are researching different methods of vehicle dynamics simulations. Starting from a simple two-wheeled vehicle model, we are showing ways to simulate the movement of vehicles with real suspensions on any surfaces. MATLAB, Simulink and Simscape provide very suitable resources for the above mentioned purposes. The benefits of such vehicle model become obvious because of the fact during the physics simulation we can access all the data we need to simulate any control algorithms for vehicles: in this article we are presenting a simple ABS control simulation.

• ##### Principles of Three-Dimensional Computer Design for Understanding Impossible Figures
167-173
Views:
162

For a better understanding of the impossible figures, it is advisable to use modern technological means by which the design of the geometry of the models gives a complete understanding of how they are made. Computer-aided 3D design completely solves this problem. That is, on the one hand, the ultimate visual variant of impossible figures is created, on the other hand, there is the possibility for real manipulation, movement, rotation and other models of space. In this study, 3D models of impossible figures are fully constructed, which are applied in the educational process in order to develop logical thinking. The steps of creating 3D geometry using open source software Blender 3D are described in details.

• ##### Automation Capabilities for the Logistics Service of Jobshop Production System
210-221
Views:
447

One of the most important subsystems of manufacturing is the logistics system for transporting materials between technological phase. It is integrated depending on the production structure. The special feature of highly flexible workshop system production is that the material handling system is typically separate and the movement needs occur independently of each other, so the flexibility of the material handling system is required to achieve the expected production goal. In practice, therefore, the organization and execution of material handling is to a considerable extent dependent on the human factor. The purpose of this research is to explore the potential for automation of material handling activities in this particular production environment.

• ##### What is worth knowing about the establishment from a work safety point of view
24-31
Views:
121

Under establishment, we mean the process that results in the creation of a new unit (eg factory, plant, office, etc.), a workplace or an existing one what will be renewed, expanded or restructured, or installed; installed on a machine, plant, appliance, whether or not for productive or non-productive purposes. It is generally true that the design, construction, use and subsequent operation of workplaces, facilities, technology, materials, energy, personal protective equipment; production, distribution, import, transportation, movement, use and use of workplaces; in the absence of these, the requirements of the scientific-technical standard can be expected. An employer, operator, and service provider must adapt to market conditions. Accordingly, it should monitor the expectations of customers, business partners, market changes, trends to adapt to expectations, and therefore constantly develop their products, services, produce reliable quality, ensure that quality meets the market expectations providing personal and material conditions to ensure that employees can effectively and safely meet market expectations. The recognized business perception of the employer is to accomplish the above, the objectives to be achieved must be formulated, priority should be given to the potential risks (with particular regard to occupational safety risks) to be measured, measures to be taken to ensure effectiveness, short-, medium- and long-term planning, investment.

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