scholarly journals Tolerance Volume Due to Joint Variable Errors in Robots

1989 ◽  
Vol 111 (4) ◽  
pp. 597-604 ◽  
Author(s):  
Woo-Jong Lee ◽  
T. C. Woo
Keyword(s):  
Confidence Level ◽  
Degrees Of Freedom ◽  
Probabilistic Approach ◽  
Automatic Generation ◽  
Linear Mapping ◽  
Precision Engineering ◽  
Probability Of Error ◽  
Robot Configuration ◽  
Joint Variable ◽  
Locational Uncertainty

The locational uncertainty of a manipulator is largely due to the errors of the joint variables. But these errors cannot be easily compensated for because they are dependent on the operation (i.e., robot-configuration). Motivated by the need to conduct precision engineering and the intellectual curiosity of geometric uncertainty, the probabilistic tolerance volume due to joint errors is investigated. By defining the locational uncertainty in Cartesian space as a tolerance volume, the investigation focuses on the automatic generation of the tolerance volume from a given confidence level. For this purpose, the linear mapping form Δq space to Δd space through Jacobian matrix is analyzed probabilistically. Probabilistic approach is advantageous since the tolerance volume by the deterministic approach is found to be unnecessarily large. With the assumption of normality of joint variables, this paper begins with the computation of the confidence level for a given tolerance volume. A fast analytic procedure, which gives a considerable time-reduction compared to the commonly used Monte-Carlo simulation, is presented. Based on the monotonic relation between confidence level and tolerance volume, the procedure is used to generate the tolerance volume covering the desired confidence level. The scheme is tested with the six degrees-of-freedom Stanford manipulator and shows a significant (more than 5 times) reduction in the size of the tolerance volume with a 0.3 percent probability of error.

PSEUDO PROBABILISTIC APPROACH TO TEST ISOMORPHISM AMONG KINEMATIC CHAINS

1997 ◽  
Vol 21 (2) ◽  
pp. 65-83 ◽  
Author(s):  
S. Shubhashis ◽  
M. Choubey ◽  
A.C. Rao
Keyword(s):  
Numerical Scheme ◽  
Degrees Of Freedom ◽  
Probabilistic Approach ◽  
Kinematic Chain ◽  
Single Degree Of Freedom ◽  
Reliable Test ◽  
Kinematic Chains ◽  
Single Degree ◽  
Unique Method ◽  
P Matrix

There is no dearth of methods to test isomorphism amongst kinematic chains. Search for a computationally easier, logically simple and unique method is still on. Present work is in quest of a reliable test to detect isomorphism among kinematic chains. Work presented here is more versatile as it incorporates more features of the kinematic chain which were not included earlier such as number and type of links, their relative dispositions in the kinematic chain, nature of adjacent links etc. The method proposed is based on the concept of pseudo-probability (pseudo means it appears to be, but not exactly. The approach does not follow in-toto the principles of probability and considerable liberty has been taken in interpreting the word probability hence the word pseudo is used along with the probability schemes). Using the resemblance of different coloured balls in an urn for the number and type of links in a kinematic chain, a matrix (named P-Matrix) representing the kinematic chain in totality is generated. For the sake of comparison a numerical scheme named, pseudo probability scheme, P-Scheme, is developed from the above P-Matrix and is used for testing isomorphism. In fact the method is more powerful in the sense that each row of the proposed P-Matrix is capable of representing the respective kinematic chain distinctly and can be used to compare the kinematic chains with same link assortments, uniquely. The proposed method, besides possessing the potential of testing the isomorphism among simple-joint, single degree of freedom kinematic chains is also capable of multi degrees of freedom and multiple-joint kinematic chains.

Automatic Generation of Equations of Motion of Mechanical Systems

2014 ◽  
Vol 611 ◽  
pp. 40-45
Author(s):  
Darina Hroncová ◽  
Jozef Filas
Keyword(s):  
Computer Simulation ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Mechanical Systems ◽  
Automatic Generation ◽  
Lagrange Equations ◽  
Kinematic Chains ◽  
Transformation Matrices

The paper describes an algorithm for automatic compilation of equations of motion. Lagrange equations of the second kind and the transformation matrices of basic movements are used by this algorithm. This approach is useful for computer simulation of open kinematic chains with any number of degrees of freedom as well as any combination of bonds.

Studi Komparatif Pendapatan Usaha Abon Ikan Dan UsahaIkan KayuChipdi Desa Lampulo Kecamatan Kuta Alam Kota Banda Aceh

2016 ◽  
Vol 1 (1) ◽  
pp. 621-630
Author(s):  
Nazilla Ulfa Nazilla ◽  
Irwan Irwan ◽  
Akhmad Baihaqi
Keyword(s):  
Confidence Level ◽  
Research Method ◽  
Degrees Of Freedom ◽  
Wood Chip ◽  
T Test ◽  
Wood Chips ◽  
Entire Population ◽  
Sampling Techniques ◽  
Average Income ◽  
Banda Aceh

Abstract - Fish floss and wood chip fish are the proceeded product made up from fish that is processed by using tuna. This research was aimed at determining how big the differences of income of fish floss and wood chip fish business. The research method used the taking sample with saturated sampling techniques (census), where the entire population was used as the sample. The results showed that the average income of fish floss was Rp 4.953.300 million, while the average income of wood chips fish was Rp 2.075.283 and after doing the statistic testing t free samples  test (Independent Samples t Test) produced tcount ttable (3.382 1.860), at the degrees of freedom (df) = 8 and a 95% confidence level. This was appropriate with the hypothesis that meant accept Ha was the income of the business of fish floss was bigger than the income of the business of wood chip fish. Keywords: Fish Floss, Wood Chip Fish, IncomeAbstrak - Abon ikan dan ikan kayu chip merupakan produk olahan berbahan dasar ikan yang diolah dengan menggunakan ikan tongkol. Tujuan penelitian ini untuk mengetahui berapa besar perbedaan pendapatan usaha abon ikan dengan usaha ikan kayu chip. Metode penelitian menggunakan pengambilan sampel dengan teknik sampling jenuh (sensus), dimana seluruh populasi dijadikan sebagai sampel. Hasil penelitian menunjukkan bahwa rata-rata pendapatan abon ikan adalah sebesar Rp 4.953.300sedangkan rata-rata pendapatan ikan kayu chip adalah sebesar Rp 2.075.283 dan setelah dilakukan pengujian statistic uji t sampel bebas (Independent Sampels t Test) menghasilkan nilai thitung ttabel (3,3821,860), pada derajat kebebasan (df) = 8 dan tingkat kepercayaan 95%. Ini sesuai dengan hipotesis yang berarti terima Ha yaitu pendapatan usaha abon ikan lebih besar dibandingkan dengan pendapatan usaha ikan kayu chip. Kata Kunci: Abon Ikan, Ikan Kayu Chip, PendapatanAbstract - Fish floss and wood chip fish are the proceeded product made up from fish that is processed by using tuna. This research was aimed at determining how big the differences of income of fish floss and wood chip fish business. The research method used the taking sample with saturated sampling techniques (census), where the entire population was used as the sample. The results showed that the average income of fish floss was Rp 4.953.300 million, while the average income of wood chips fish was Rp 2.075.283 and after doing the statistic testing t free samples  test (Independent Samples t Test) produced tcount ttable (3.382 1.860), at the degrees of freedom (df) = 8 and a 95% confidence level. This was appropriate with the hypothesis that meant accept Ha was the income of the business of fish floss was bigger than the income of the business of wood chip fish. Keywords: Fish Floss, Wood Chip Fish, IncomeAbstrak - Abon ikan dan ikan kayu chip merupakan produk olahan berbahan dasar ikan yang diolah dengan menggunakan ikan tongkol. Tujuan penelitian ini untuk mengetahui berapa besar perbedaan pendapatan usaha abon ikan dengan usaha ikan kayu chip. Metode penelitian menggunakan pengambilan sampel dengan teknik sampling jenuh (sensus), dimana seluruh populasi dijadikan sebagai sampel. Hasil penelitian menunjukkan bahwa rata-rata pendapatan abon ikan adalah sebesar Rp 4.953.300sedangkan rata-rata pendapatan ikan kayu chip adalah sebesar Rp 2.075.283 dan setelah dilakukan pengujian statistic uji t sampel bebas (Independent Sampels t Test) menghasilkan nilai thitung ttabel (3,3821,860), pada derajat kebebasan (df) = 8 dan tingkat kepercayaan 95%. Ini sesuai dengan hipotesis yang berarti terima Ha yaitu pendapatan usaha abon ikan lebih besar dibandingkan dengan pendapatan usaha ikan kayu chip. Kata Kunci: Abon Ikan, Ikan Kayu Chip, Pendapatan

Design of parallel robots in microrobotics

Robotica ◽  
1997 ◽  
Vol 15 (4) ◽  
pp. 417-420 ◽  
Author(s):  
Eric Pernette ◽  
Simon Henein ◽  
Ivo Magnani ◽  
Reymond Clavel
Keyword(s):  
High Precision ◽  
Degrees Of Freedom ◽  
Design Guidelines ◽  
Parallel Robots ◽  
Precision Engineering ◽  
The Past ◽  
Elastic Joints ◽  
Increasing Demand ◽  
Very High

During the past few years, there has been an increasing demand in the field of precision engineering for fine motion in multi-degrees of freedom systems. These applications motivated the development of a new robotics field called microrobotics. In this paper, we review both the design guidelines for microrobots and the advantages of using parallel robots in very high precision applications. Parallel micromanipulators using elastic joints as well as structures manufactured in single solid and metallic bellows are introduced.

scholarly journals Probabilistic estimation of glacier volume and glacier bed topography: the Andean glacier Huayna West

2013 ◽  
Vol 7 (4) ◽  
pp. 3931-3967
Author(s):  
V. Moya Quiroga ◽  
A. Mano ◽  
Y. Asaoka ◽  
K. Udo ◽  
S. Kure ◽  
...  
Keyword(s):  
Confidence Level ◽  
Probabilistic Approach ◽  
Glacier Retreat ◽  
Probabilistic Estimation ◽  
Bed Topography ◽  
Plastic Behaviour ◽  
The Mean ◽  
Optimal Approach ◽  
Basal Shear ◽  
Lognormal Probability

Abstract. Glacier retreat will increase sea level and decrease fresh water availability. Glacier retreat will also induce morphologic and hydrologic changes due to the formation of glacial lakes. Hence, it is important not only to estimate glacier volume, but also to understand the spatial distribution of ice thickness. There are several approaches for estimating glacier volume and glacier thickness. However, it is not possible to select an optimal approach that works for all locations. It is important to analyse the relation between the different glacier volume estimations and to provide confidence intervals of a given solution. The present study presents a probabilistic approach for estimating glacier volume and its confidence interval. Glacier volume of the Andean glacier Huayna West was estimated according to different scaling relations. Besides, glacier volume and glacier thickness were estimated assuming plastic behaviour. The present study also analysed the influence of considering a variable glacier density due to ice firn densification. It was found that the different estimations are described by a lognormal probability distribution. Considering a confidence level of 90%, the estimated glacier volume is 0.0275 km3 ± 0.0052 km3. Considering a confidence level of 90%, the estimated glacier thickness is 24.98 m with a confidence of ±4.67 m. The mean basal shear stress considering plastic behaviour is 82.5 kPa. The reconstruction of glacier bed topography showed the future formation of a glacier lake with a maximum depth of 32 m.

scholarly journals PENGARUH LOAN TO DEPOSIT RATIO (LDR) TERHADAP EARNING PER SHARE (EPS) DI PT BNI Tbk. PERIODE 2008-2017

2020 ◽  
Vol 3 (2) ◽  
pp. 133-141
Author(s):  
R. Deden Adhianto
Keyword(s):  
Correlation Coefficient ◽  
Confidence Level ◽  
Degrees Of Freedom ◽  
Quantitative Method ◽  
Pearson Correlation ◽  
Coefficient Of Determination ◽  
Pearson Correlation Coefficient ◽  
Test Results ◽  
Know How ◽  
Strong Relation

This research aims to know how much the effetc of loan to deposit ratio (LDR) against earning per share (EPS) at PT Bank BNI Tbk. The method that is used in this research is quantitative method. By taking samples of research from 2008 to 2017. Based on the analysis of the data, it indicates that the loan to deposit ratio has strong relation with earning per share as of the value of pearson correlation coefficient is 0,902%. Loan to deposit ratio also has positive and significan effect on the earning per share with a coefficient of determination amounted to 81,36 % and T test results showes t calculate>t table amounted to (5,898>2,360) confidence level (0,05) with degrees of freedom 8 therefore Ho rejected and H1 accepted. The suggestion given to maintain level the BI’ LDR standar, to avoid problem decrease in CAR standar and result high EP.

scholarly journals A New Model to Study Fatigue in Dental Implants Based on Probabilistic Finite Elements and Cumulative Damage Model

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
María Prados-Privado ◽  
José Antonio Bea ◽  
Rosa Rojo ◽  
Sérgio A. Gehrke ◽  
José Luis Calvo-Guirado ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Load Transfer ◽  
Probabilistic Approach ◽  
Damage Model ◽  
Cumulative Damage ◽  
Occlusal Plane ◽  
Good Precision ◽  
Principal Stresses ◽  
Internal Connection ◽  
Cumulative Damage Model

The aim of this study was to predict the fatigue life of two different connections of a dental implant as in load transfer to bone. Two three-dimensional models were created and assembled. All models were subjected to a natural masticatory force of 118 N in the angle of 75° to the occlusal plane. All degrees of freedom in the inferior border of the cortical bone were restrained, and the mesial and distal borders of the end of the bone section were constrained. Fatigue material data and loads were assumed as random variables. Maximum principal stresses on bone were evaluated. Then, the probability of failure was obtained by the probabilistic approach. The maximum principal stress distribution predicted in the cortical and trabecular bone is 32 MPa for external connection and 39 MPa for internal connection. A mean life of 103 and 210 million cycles were obtained for external and internal connection, respectively. Probability cumulative function was also evaluated for both connection types. This stochastic model employs a cumulative damage model and probabilistic finite element method. This methodology allows the possibility of measured uncertainties and has a good precision on the results.

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