1,721,053 research outputs found
Perancangan laluan robot menggunakan fungsi harmonik melalui kaedah lelaran sapuan suku
No full textKertas kajian ini mengemukakan aplikasi fungsi harmonik dalam menyelesaikan masalah perancangan laluan robot. Fungsi harmonik diperolehi dengan menyelesaikan persamaan Laplace. Dalam kajian ini, fungsi-fungsi harmonik bertindak sebagai nilai-nilai potensi pada setiap titik dalam persekitaran robot. Nilai-nilai potensi ini kemudiannya digunakan untuk mencari laluan dari titik mula sehinggalah ke titik destinasi yang telah ditetapkan. Bagi mendapatkan fungsi-fungsi harmonik ini, pendekatan yang paling biasa digunakan adalah kaedah beza terhingga iaitu lelaran Jacobi, Gauss-Seidel dan Successive Over-relaxation (SOR). Namun, kaedah-kaedah lelaran yang lazim ini terlalu perlahan, terutamanya apabila melibatkan persekitaran yang luas. Oleh itu, kajian ini mencadangkan kaedah yang lebih pantas menggunakan gabungan teknik lelaran sapuan suku dengan lelaran SOR. Keputusan ujikaji menunjukkan kaedah-kaedah yang dicadangkan ini telah berjaya mengurangkan masa pengiraan fungsi-fungsi harmonik secara drastik. Ini secara langsung telah meningkatkan prestasi keseluruhan algoritma perancangan laluan, terutamanya aspek masa perlaksanaan
Path planning simulation using harmonic potential fields through four point-edgsor method via 9-point laplacian
No full textRobot path planning using family of SOR iterative methods with laplacian behaviour-based control
Full text linkA truly autonomous robot must have the capability to find path from its start point to a specified goal point. This study proposed a robot path planning technique that relies on the use of Laplace's equation to constrain the generation of potential values. It is based on the theory of heat transfer, when there exist a temperature gradient within a surface, heat energy will flow from the region of high temperature at heat source to the region of low temperature at heat sink. In this model, high Laplacian potentials are assigned to outer boundary, inner walls and obstacles. Whilst, the goal point is assigned the lowest and no Laplacian potentials are assigned to all other free spaces. The Laplacian potentials for nodes on free spaces are then computed iteratively using numerical techniques. In the literature, computing these Laplacian potentials using numerical techniques produced encouraging results. The numerical implementations of these previous works, however, were only based on family of point iterative methods i.e. Jacobi, Gauss-Seidel and Successive Overrelaxation (SOR). These standard methods are too slow when handling large environment. Therefore, this study introduces the concepts of half-sweep and quarter-sweep iterations, and initiates the first application of using family of Point SOR and family of Four Point-Block SOR iterative methods for computing the Laplacian potentials to solve the path planning problem. The implementations employ two finite difference discretization schemes that are based on 5-Point and 9-Point Laplacian. Within the family of Point SOR iterative methods, the simulation results shows that the application of half-sweep and quarter-sweep concepts reduced the computational complexities of the algorithms by approximately 50% and 75%, respectively. Significantly, simulations with family of Four Point-Block SOR iterative methods provide even faster computation. In terms of iterations count, the iterative methods based on the 9-Point Laplacian give the less number of iterations than the 5-Point Laplacian. Whilst, in terms of execution time, the speed difference between iterative methods based on 5-Point and 9-Point Laplacian is very minimal. Once the Laplacian potentials are obtained, the standard Gradient Descent Search (GDS) technique is performed for path tracing to the goal point. The existing GDS, however, suffers from the occurrence of flat region in a more difficult environment which causing the path generation to fail. Thus, this study proposes a new control known as Laplacian Behaviour-Based Control (LBBC) to overcome such problem. Due to its robustness, the LBBC successfully generated smooth path even in a more complex configuration space. Therefore in conclusion, the significant contribution of this study is in introducing for the first time the fast half-sweep and quarter-sweep iterative methods using families of Point SOR and Four Point-Block SOR methods via 5-Point and 9-Point Laplacian. These faster iterative methods overcome the slow performances of the existing standard methods, particularly when handling large environment. In addition, the newly proposed LBBC overcomes the drawback of the existing GDS that face difficulty when handling complex environment. Finally, the path planning problem is solved by combining the fast iterative method with the robust path searching LBBC technique, so that the path planning algorithm is capable of handling large and complex environment
Indoor path planning using harmonic functions via half-sweep arithmetic mean method
Full text linkThis paper presents the application of a two-stage Half-Sweep Arithmetic Mean (HSAM) iterative method to obtain the Harmonic functions to solve the path planning problem in a 2D indoor environment. Several path planning simulations in a known indoor environment were conducted to examine the effectiveness of the proposed method. It is shown that the proposed path planning algorithm is capable of generating smooth paths from various start and goal positions. Also, numerical results show that the proposed HSAM method converges much faster than the existing iterative methods, thus it drastically improves the overall performance of the path planning algorith
Path planning for mobile robot using 4EGSOR via Nine-Point Laplacian (4EGSOR9L) iterative method
Full text linkThis paper presents an attempt to solve path planning problem for a mobile robot operating in indoor environment model using iterative numerical technique. It is based on the use of Laplace’s Equation to compute the potential functions in the environment grid model of the robot. The proposed block iterative method, better known as Four Point-Explicit Group via Nine-Point Laplacian (4EGSOR9L), employs a finite difference scheme to compute the potential functions to be used in generating smooth path between start and goal points. The simulation results demonstrate that the proposed 4EGSOR9L method performs faster than the previous
methods in computing the potential functions of the
environment model
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Path planning for indoor mobile robot using half-sweep SOR via nine-point Laplacian (HSSOR9L)
Full text linkThis paper proposed fast Half-Sweep SOR via Nine-Point Laplacian (HSSOR9L) iterative method for solving path planning problem for a mobile robot operating in indoor environment model. It is based on the use of Laplace’s Equation to constraint the distribution of potential values in the environment of the robot. Fast computation with half-sweep iteration is obtained by considering only half of whole points in the configuration model. The inclusion of SOR and 9-point Laplacian into the formulation further speeds up the computation. The simulation results show that HSSOR9L performs much faster than the previous iterative methods in computing the potntial values to be used for generating smooth path from a given initial point to a specified goal position
Path Planning in Structured Environment Using Harmonic Potentials via Half-Sweep Modified AOR Method
No full textPath planning of indoor mobile robot using harmonic potentials via half-sweep modified SOR method
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