Obstacle Block Research Articles

Radom Intermediate Points Based Path Planning in Unknown Environment

This paper presents RandomBug, a novel real-time path planning algorithm, for an autonomous mobile agent in completely unknown environment. According to this algorithm, all the planned paths are described and stored in the form of vectors. When the agent moves along the planned paths, it only considers the rotation angle and the movement distance in a single direction. The algorithm combines range sensor data with a safety radius to determine the blocking obstacles and calculate the shorter path by choosing the random intermediate points. When there is obstacle blocking in the current path, the intermediate points will be calculated randomly and the planned path will be regenerated by inserting the selected random intermediate points. Simulation results are given to show the effectiveness of the proposed algorithm.

Evolving patterns of internal security cooperation: lessons from the Schengen and Prüm laboratories

This article discusses evolving patterns of internal security cooperation that start in the realm of international public law and end up more or less entirely in the treaty framework of the European Union. By applying the theory of clubs (Buchanan) it shows the fertility as well as limitations of a public goods approach to analyse and explain such instances of differentiated integration and to assess their effectiveness. By way of the comparative analysis of the Schengen regime and the Prüm Treaty it analyses five main stages of an internal security club's life circle from the causing obstacle (blocking of a certain policy) to the final incorporation endgame. Both clubs under investigation produced so-called network goods with negative rivalry logic, i.e. the more members participate and ‘consume’ the good the higher the benefit for all. However, it is also shown that club formation and expansion could not only be understood as a strategically rational process, and that various contextual costs inhibited the formation and eventual expansion of the clubs. The article concludes that incorporation efforts necessarily lead to pick-and-choose situations that preclude full uniformity; consequently, outside treaty clubs tend to create á la carte fragmentation to a certain degree.

A new ant colony-based routing algorithm with unidirectional link in UV mesh communication wireless network

Aiming at the unidirectional links coming from nodes with different transmitting power and the obstacle blocking in UV mesh wireless communication network and the traditional ant colony algorithm only supporting bidirectional links, a new ant colony based routing algorithm with unidirectional link in UV mesh communication wireless network is proposed. The simulation results show that the proposed algorithm can improve the overall network connectivity and the survivability by supporting the combination of unidirectional link and bidirectional link.

New electro-vibroimpact system

In this paper, a new vibro-impact mechanism based on a solenoid-actuated vibrator and its optimization are presented. The vibratory unit deploying electro-mechanical interactions of a conductor with oscillating magnetic field has been realized. The combination of resonance in an RLC circuit and a solenoid is found to create an oscillatory motion to the metal bar within the solenoid. This results in impacts of the metal bar on an obstacle block. Unanimously, the electromagnetic force generated within the solenoid acts as a non-linear electromagnetic spring. Hence, a vibro-impact mechanism gets created. This system is improved by adding a solid-state relay in series to the RLC circuit, which switches the power supply on and off periodically in accordance to a train of square waves produced by a function generator. This new control over the supplied harmonic voltage allows a small scale in the geometry of the vibratory unit but significantly increases the magnitude of impact forces and the progression rates obtained. This implies a very promising deployment of the mechanism in actual soil conditions.

Experimental study and mathematical modelling of a new of vibro-impact moling device

In this paper experimental study and mathematical modelling of newly designed vibro-impact moling rig are presented. The design is based on electro-mechanical interactions of a conductor with an oscillating magnetic field. The rig consists of a metal bar placed within a solenoid which is connected to an RLC circuit, and an obstacle block positioned nearby. Both the solenoid and the block are attached to a base board. Externally supplied alternating voltage causes the bar to oscillate and hit the block resulting in the forward motion of the base board mimicking a mole penetration through the soil. By varying the excitation voltage and the capacitance in the circuit, a variety of system responses can be obtained. In the paper the rig design and experimental procedure are explained in detail, and the mathematical modelling of the rig is described. Then the obtained coupled electro-mechanical equations of motion are integrated numerically, and a comparison between experimental results and numerical predictions is presented.