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Kinematic Synthesis Of Spatial Mechanisms Using Algebra Of Exponential Rotation MatricesSoltani, Fariborz 01 February 2005 (has links) (PDF)
The major part of this thesis has been devoted to path and motion generation synthesis of spatial mechanisms. For the first time kinematic synthesis methods have been developed based on the algebra of exponential rotation matrices. Besides modeling spatial pairs such as spheric, cylindric and Hook' / s joints by combinations of revolute and prismatic joints and applying Denavit-Hartenberg' / s convention, general loop closure equations have been presented for path and motion generation synthesis of any spatial mechanism with lower kinematic pairs. In comparison to the existing synthesis methods the main advantage of the methods presented in this thesis is that, general loop closure equations have been presented for any kind of spatial mechanism with lower kinematic pairs. Besides these methods enable the designer to benefit the advantages of the algebra of exponential rotation matrices.
In order to verify the applicability of the synthesis methods presented in this thesis, the general loop closure equations of RSHR, RCCR and RSSR-SC mechanisms have been determined and then using these equations six numerical examples have been solved. Some tables have been presented based on the determined loop closure equations which reveal useful information about the number of precision points or positions that can be considered for the kinematic synthesis of the above mentioned mechanisms and the number of free parameters.
In numerical examples, the mechanisms have been synthesized based on the general loop closure equations and the synthesis algorithms presented in the thesis. Although in some cases semi-analytical solutions have been obtained, in most of the cases, the loop closure equations were solved by computer programs written by Mathcad. The input angle-output angle diagrams drawn at the end of each numerical example illustrate the motion continuity of the mechanisms and that branching has been avoided. Detailed information has been given about the computer programs and the difficulties which may arise while synthesizing spatial mechanisms.
In addition to the above mentioned points, a mobility analysis has been done for the RCCR mechanism and some inequalities have been obtained in terms of the link lengths. The swing angle diagram of the RCCR linkage has been drawn too.
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Orientation estimation and movement recognition using low cost sensorsLópez Revuelta, Álvaro January 2017 (has links)
Orientation estimation is a very well known topic in many fields such as in aerospace or robotics. However, the sensors used are usually very ex- pensive, heavy and big, which make them not suitable for IoT (Internet of Things) based applications. This thesis presents a study of how different sensor fusion algorithms perform in low cost hardware and in high acceler- ation scenarios. For this purpose, an Arduino MKR1000 is used together with an accelerometer, gyroscope and magnetometer. The objective of the thesis is to choose the most suitable algorithm for the purposed practical application, which consists on attaching the device to a moving object, such as a skate board or a bike. Once the orientation is estimated, a movement recognition algorithm that was developed is able to match what trick or movement was performed. The algorithm chosen was the Madgwick one with some minor adjustments, which uses quaternions for the estimation and is very resilient when the device is under strong external accelerations.
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