Theses and Dissertationshttp://nur.nu.edu.kz:80/handle/123456789/11672024-03-29T10:39:32Z2024-03-29T10:39:32ZRobotic Construction of Tensegrity StructuresIssa, Margulanhttp://nur.nu.edu.kz:80/handle/123456789/35932021-02-05T07:23:51Z2017-04-01T00:00:00ZRobotic Construction of Tensegrity Structures
Issa, Margulan
Tensegrity based design is emerging as an active research field. Tensegrity structures
can be constructed with minimal weight compared to the traditional ones. They can
also have stability and durability without relying on gravity. These merits make them
ideal for the construction of orbital structures such as space stations. Even though
the researchers have recently crafted elegant theories for the statics and dynamics of
tensegrity, there are many hurdles for their active utilization in space construction.
Due to the need for attaching strings in complex geometries and precise tensioning of
these, the labor and skill intensive construction of these tensegrities in space cannot
be accomplished by humans. With recent advances in robotics especially in embedded
computing, sensing and motion planning, robots can be summoned to tackle the
automated construction problem of tensegrities. To the best of the author’s knowledge,
an automated construction framework for tensegrities does not exist. This
thesis focuses on this problem. Firstly, we describe our assembly-friendly tensegrity
struts with integrated strings and tensioners. Secondly, we present the development
and implementation of a specialized robot end-effector for tensegrity construction.
This end-effector with embedded sensors and computation is capable of measuring
the string tension based on vibration frequency, attaching/detaching strings and also
tensioning them. Using these components, we developed a framework for robotic
construction of tensegrity structures. We show the efficacy of our framework by realworld
experiments. In particular, we constructed a 3-strut and 9-string tensegrity
prism which can serve as a building block for more complex structures.
2017-04-01T00:00:00ZMechanical Design and Kinematic Analysis of a Spherical Parallel Manipulator with Coaxial Input ShaftsTursynbek, Iliyashttp://nur.nu.edu.kz:80/handle/123456789/35922021-02-05T07:23:51Z2017-05-01T00:00:00ZMechanical Design and Kinematic Analysis of a Spherical Parallel Manipulator with Coaxial Input Shafts
Tursynbek, Iliyas
In this thesis a spherical parallel manipulator with coaxial input shafts (Coaxial SPM)
is under study. It is a part of a bigger family of spherical parallel manipulators (SPM)
with a special feature of unlimited roll rotation around its axis. This feature makes
the Coaxial SPM of high interest for applications in motion control system. First, an
approach for obtaining unique forward and inverse kinematics solutions is introduced,
in order to relate the angular position of the manipulator servomotors to the position
and orientation of Coaxial SPM mobile platform and vice versa. Then, a configuration
space of the manipulator is defined by using a numerical procedure, in order to
guarantee the absence of singularities and of collision between the manipulator links
during the manipulator motion. Afterwards, the Cartesian space of the manipulator
is generated. Results of these analyses are applied to the assembled mechanical
prototype of Coaxial SPM for experimental verifications.
2017-05-01T00:00:00ZData Aggregation in Wireless Sensor Networks with Multiple SinksYestemirova, Gaukharhttp://nur.nu.edu.kz:80/handle/123456789/35892021-02-05T07:23:49Z2017-04-01T00:00:00ZData Aggregation in Wireless Sensor Networks with Multiple Sinks
Yestemirova, Gaukhar
The invention of wireless sensor networks (WSNs) has caused a technological breakthrough
in almost all industry fields that need to acquire regular and reliable real-time
data from the field of interest. Today WSNs are used in many applications, including
environmental, industrial, health care, and military.
A WSN is a network comprised of sensors devices, usually called nodes, and a
designated device called a sink to which nodes transmit their sensed data. Nodes are
low-cost, battery-powered devices with limited memory and computational power.
Usually WSNs are deployed and left unattended for a long time. During this time the
WSN can experience different faulty scenarios. For example, nodes and sink can crash
or communication between them can go down. In such cases, the network becomes
useless as the sink will not be able to collect data from nodes. One way to increase the
reliability of such WSNs is to deploy them with more than one sink so that when one
sink goes down other sinks could forward collected data. A number of data collection
protocols have been proposed so far. However, they have been proposed mainly for
WSNs with a single sink. Existing protocols developed for WSNs with a single sink
does not show the similar system efficiency to WSNs with multiple sinks.
In this thesis work, we propose three data aggregation protocols for WSNs with
multiple sinks: i) an adjusted form of Minimum Spanning Tree (MST); ii) two adjusted
forms of Shortest Path Tree (SPT) and i) Maximum Spanning Backbone (MSB)
that try to minimize the number of message transmissions during data collection. In
all cases we first build a tree and then highlight the set of nodes that connect all the
sinks and call them backbone nodes. These backbone nodes first collect the data from
the nodes, then send aggregated data to all the sinks. We show the performance of
our proposed protocols using simulation program. The simulation results from least
to most backbone nodes as the following: MSB, two adjustments of SPT and MST.
2017-04-01T00:00:00ZRobotic Assembly Planning of Tensegrity StructuresNurimbetov, Birzhanhttp://nur.nu.edu.kz:80/handle/123456789/35872021-02-05T07:23:48Z2017-04-01T00:00:00ZRobotic Assembly Planning of Tensegrity Structures
Nurimbetov, Birzhan
Tensegrity structures provide durability and stability with minimal weight. Thanks
to these properties, use of tensegrity structures for space applications is becoming
an active research area. One of the main challenges is the automated construction
of such structures in space. In this thesis, we present a framework for the automated
assembly planning of tensegrity structures using an industrial manipulator
(Staubli TX90XL) equipped with a purpose-specific end-effector. We leverage the
recent advances in sampling-based motion planning to create the motion plans (i.e.
the reference trajectories for the manipulator joints). Specifically, we divided the
assembly planning problem into three stages. In the first stage, the initial position
and orientation of the given tensegrity structure with respect to the assembly robot
is determined using a motion-planning integrated forward elimination search. In the
second stage, a feasible assembly sequence of the strings is found using backward
disassembly search. Lastly, individual robot motion plans for attaching each string
to the bars for the given tensegrity configuration is generated using RRT* algorithm.
The efficacy of the framework was demonstrated using an extensive set of simulation
and real-world experiments dealing with the assembly of a 3-strut and 9-string tensegrity
prism structure, which can be utilized as a building block of complex tensegrity
structures.
2017-04-01T00:00:00ZDevelopment of a Lightweight Biped RobotAubakir, Bauyrzhanhttp://nur.nu.edu.kz:80/handle/123456789/35862021-02-05T07:23:48Z2017-05-01T00:00:00ZDevelopment of a Lightweight Biped Robot
Aubakir, Bauyrzhan
Robotics, as a research and technical field, finds inspiration in nature. In particular,
bipedal robots, which structure and kinematics reproduce the lower limbs of a human
body, are the first step toward functional humanoid robots. This document describes
the development phases of a lightweight biped robot under construction at the department
of Robotics and Mechatronics in Nazarbayev University. The mechanical
design is the primary focus of this work; nevertheless, a big effort was also dedicated
to formalize and realize the electrical, sensorial and software subsystems. By using 3D
printing techniques and lightweight materials a lower power consumption and higher
power over weight ratio was reached in comparison with state-of-the-art robots having
comparable dimensions. Furthermore, thanks to a lower links inertia the system is
inherently safer when operating in environment where humans are present. A detailed
description of the robot kinematics and the methodology followed to dimension the
actuation system is provided together with preliminary results on the execution of
different postures and gaits.
2017-05-01T00:00:00ZDevelopment of a Neuromorphic Control System for a Biped RobotKeldibek, Aminahttp://nur.nu.edu.kz:80/handle/123456789/35842021-02-05T07:23:47Z2017-04-01T00:00:00ZDevelopment of a Neuromorphic Control System for a Biped Robot
Keldibek, Amina
Humanoid robots are developed around the world with the purpose to assist humans in their
domestic and public activities and operate in unstructured and hazardous environments. To
accomplish this effectively, intelligent humanoids should be autonomous, to accomplish
high-level human tasks without help, and adaptable, to be able to react to dynamic changes
and external disturbances in operating environments. The primary objective of this thesis is
to investigate how biologically plausible methods such as reservoir computing and rewardmodulated
learning can be used for generating robust sensory-motor outputs and achieving
adaptability of the biped system. Recurrent neural networks architecture is studied on
two robot systems: first is Asimo humanoid and second is biped developed at Nazarbayev
University.
2017-04-01T00:00:00Z