Matching Items (113)

132888-Thumbnail Image.png

Design and Simulation of Controllers for Multi-Robot Transport over Inclines

Description

The goal of this thesis is designing controllers for swarm robots transport a payload over inclines. Several fields of study are related to this study, including control theory, dynamic modeling and programming. MATLAB, a tool of design controller and simulation,

The goal of this thesis is designing controllers for swarm robots transport a payload over inclines. Several fields of study are related to this study, including control theory, dynamic modeling and programming. MATLAB, a tool of design controller and simulation, is used in this thesis.

To achieve this goal, a model of swarm robots transportation should be designed, which is cruise control for this scenario. Secondly, based on free body diagram, force equilibrium equation can be deduced. Then, the function of plant can be deduced based on cruise control and force equilibrium equations. Thirdly, list potential controllers, which may implement desired controls of swarm robots, and test their performance. Modify value of gains and do simulations of these controller. After analyzing results of simulation, the best controller can be selected.

In the last section, there is conclusion of entire thesis project and pointing out future work. The section of future work will mention potential difficulties of building entire control system, which allow swarm robots transport over inclines in real environment.

Contributors

Agent

Created

Date Created
2019-05

132909-Thumbnail Image.png

Design and Fabrication of a Low-Cost Gripper for a Swarm Robotic Platform

Description

This thesis details the design and construction of a torque-controlled robotic gripper for use with the Pheeno swarm robotics platform. This project required expertise from several fields of study including: robotic design, programming, rapid prototyping, and control theory. An electronic

This thesis details the design and construction of a torque-controlled robotic gripper for use with the Pheeno swarm robotics platform. This project required expertise from several fields of study including: robotic design, programming, rapid prototyping, and control theory. An electronic Inertial Measurement Unit and a DC Motor were both used along with 3D printed plastic components and an electronic motor control board to develop a functional open-loop controlled gripper for use in collective transportation experiments. Code was developed that effectively acquired and filtered rate of rotation data alongside other code that allows for straightforward control of the DC motor through experimentally derived relationships between the voltage applied to the DC motor and the torque output of the DC motor. Additionally, several versions of the physical components are described through their development.

Contributors

Created

Date Created
2019-05

132937-Thumbnail Image.png

Attitudes Towards Autonomous Vehicles (AVs): Insights Gained through Surveys and Proposed Experiments on a Small-Scale Traffic Testbed

Description

In the next decade or so, there will be a shift in the industry of transportation across the world. Already today we have autonomous vehicles (AVs) tested in the Greater Phoenix area showing that the technology has improved to a

In the next decade or so, there will be a shift in the industry of transportation across the world. Already today we have autonomous vehicles (AVs) tested in the Greater Phoenix area showing that the technology has improved to a level available to the public eye. Although this technology is not yet released commercially (for the most part), it is being used and will continue to be used to develop a safer future. With a high incidence of human error causing accidents, many expect that autonomous vehicles will be safer than human drivers. They do still require driver attention and sometimes intervention to ensure safety, but for the most part are much safer. In just the United States alone, there were 40,000 deaths due to car accidents last year [1]. If traffic fatalities were considered a disease, this would be an epidemic. The technology behind autonomous vehicles will allow for a much safer environment and increased mobility and independence for people who cannot drive and struggle with public transport. There are many opportunities for autonomous vehicles in the transportation industry. Companies can save a lot more money on shipping by cutting the costs of human drivers and trucks on the road, even allowing for simpler drop shipments should the necessary AI be developed.Research is even being done by several labs at Arizona State University. For example, Dr. Spring Berman’s Autonomous Collective Systems Lab has been collaborating with Dr. Nancy Cooke of Human Systems Engineering to develop a traffic testbed, CHARTopolis, to study the risks of driver-AV interactions and the psychological effects of AVs on human drivers on a small scale. This testbed will be used by researchers from their labs and others to develop testing on reaction, trust, and user experience with AVs in a safe environment that simulates conditions similar to those experienced by full-size AVs. Using a new type of small robot that emulates an AV, developed in Dr. Berman’s lab, participants will be able to remotely drive around a model city environment and interact with other AV-like robots using the cameras and LiDAR sensors on the remotely driven robot to guide them.
Although these commercial and research systems are still in testing, it is important to understand how AVs are being marketed to the general public and how they are perceived, so that one day they may be effectively adopted into everyday life. People do not want to see a car they do not trust on the same roads as them, so the questions are: why don’t people trust them, and how can companies and researchers improve the trustworthiness of the vehicles?

Contributors

Agent

Created

Date Created
2019-05

133580-Thumbnail Image.png

Image Processing for an Autonomous Throwing Arm and Smart Catching System

Description

In this paper, we propose an autonomous throwing and catching system to be developed as a preliminary step towards the refinement of a robotic arm capable of improving strength and motor function in the limb. This will be accomplished by

In this paper, we propose an autonomous throwing and catching system to be developed as a preliminary step towards the refinement of a robotic arm capable of improving strength and motor function in the limb. This will be accomplished by first autonomizing simpler movements, such as throwing a ball. In this system, an autonomous thrower will detect a desired target through the use of image processing. The launch angle and direction necessary to hit the target will then be calculated, followed by the launching of the ball. The smart catcher will then detect the ball as it is in the air, calculate its expected landing location based on its initial trajectory, and adjust its position so that the ball lands in the center of the target. The thrower will then proceed to compare the actual landing position with the position where it expected the ball to land, and adjust its calculations accordingly for the next throw. By utilizing this method of feedback, the throwing arm will be able to automatically correct itself. This means that the thrower will ideally be able to hit the target exactly in the center within a few throws, regardless of any additional uncertainty in the system. This project will focus of the controller and image processing components necessary for the autonomous throwing arm to be able to detect the position of the target at which it will be aiming, and for the smart catcher to be able to detect the position of the projectile and estimate its final landing position by tracking its current trajectory.

Contributors

Agent

Created

Date Created
2018-05

134271-Thumbnail Image.png

Robotic 3D Mapping for Virtual Reality Implementation

Description

In recent years, environment mapping has garnered significant interest in both industrial and academic settings as a viable means of generating comprehensive virtual models of the physical world. These maps are created using simultaneous localization and mapping (SLAM) algorithms that

In recent years, environment mapping has garnered significant interest in both industrial and academic settings as a viable means of generating comprehensive virtual models of the physical world. These maps are created using simultaneous localization and mapping (SLAM) algorithms that combine depth contours with visual imaging information to create rich, layered point clouds. Given the recent advances in virtual reality technology, these generated point clouds can be imported onto the Oculus Rift or similar headset for virtual reality implementation. This project deals with the robotic implementation of RGB-D SLAM algorithms on mobile ground robots to generate complete point clouds that can be processed off-line and imported into virtual reality engines for viewing in the Oculus Rift. This project uses a ground robot along with a Kinect sensor to collect RGB-D data of the surrounding environment to build point cloud maps using SLAM software. These point clouds are then exported as object or polygon files for post-processing in software engines such as Meshlab or Unity. The point clouds generated from the SLAM software can be viewed in the Oculus Rift as is. However, these maps are mainly empty space and can be further optimized for virtual viewing. Additional techniques such as meshing and texture meshing were implemented on the raw point cloud maps and tested on the Oculus Rift. The aim of this project was to increase the potential applications for virtual reality by taking a robotic mapping approach to virtual reality environment development. This project was successful in achieving its objective. The following report details the processes used in developing a remotely-controlled robotic platform that can scan its environment and generate viable point cloud maps. These maps are then processed off line and ported into virtual reality software for viewing through the Oculus Rift.

Contributors

Created

Date Created
2017-05

134393-Thumbnail Image.png

Implementation of Variable Damping to Gait Rehabilitation Technology

Description

Walking ability is a complex process that is essential to humans, critical for performing a range of everyday tasks and enables a healthy, independent lifestyle. Human gait has evolved to be robust, adapting to a wide range of external stimuli,

Walking ability is a complex process that is essential to humans, critical for performing a range of everyday tasks and enables a healthy, independent lifestyle. Human gait has evolved to be robust, adapting to a wide range of external stimuli, including variable walking surface compliance. Unfortunately, many people suffer from impaired gait as a result of conditions such as stroke. For these individuals, recovering their gait is a priority and a challenge. The ASU Variable Stiffness Treadmill (VST) is a device that is able to the change its surface compliance through its unique variable stiffness mechanism. By doing this, the VST can be used to investigate gait and has potential as a rehabilitation tool. The objective of this research is to design a variable damping mechanism for the VST, which addresses the need to control effective surface damping, the only form of mechanical impedance that the VST does not currently control. Thus, this project will contribute toward the development of the Variable Impedance Treadmill (VIT), which will encompass a wider range of variable surface compliance and enable all forms of impedance to be con- trolled for the first time. To achieve this, the final design of the mechanism will employ eddy current damping using several permanent magnets mounted to the treadmill and a large copper plate stationed on the ground. Variable damping is obtained by using lead screw mechanisms to remove magnets from acting on the copper plate, which effectively eliminates their effect on damping and changes the overall treadmill surface damping. Results from experimentation validate the mechanism's ability to provide variable damping to the VST. A model for effective surface damping is generated based on open-loop characterization experiments and is generalized for future experimental setups. Overall, this project progresses to the development of the VIT and has potential applications in walking surface simulation, gait investigation, and robot-assisted rehabilitation technology.

Contributors

Agent

Created

Date Created
2017-05

134544-Thumbnail Image.png

An Adaptive Boundary Coverage Control Strategy for Swarm Robotic Systems

Description

This thesis presents an approach to design and implementation of an adaptive boundary coverage control strategy for a swarm robotic system. Several fields of study are relevant to this project, including; dynamic modeling, control theory, programming, and robotic design. Tools

This thesis presents an approach to design and implementation of an adaptive boundary coverage control strategy for a swarm robotic system. Several fields of study are relevant to this project, including; dynamic modeling, control theory, programming, and robotic design. Tools and techniques from these fields were used to design and implement a model simulation and an experimental testbed. To achieve this goal, a simulation of the boundary coverage control strategy was first developed. This simulated model allowed for concept verification for different robot groups and boundary designs. The simulation consisted of a single, constantly expanding circular boundary with a modeled swarm of robots that autonomously allocate themselves around the boundary. Ultimately, this simulation was implemented in an experimental testbed consisting of mobile robots and a moving boundary wall to exhibit the behaviors of the simulated robots. The conclusions from this experiment are hoped to help make further advancements to swarm robotic technology. The results presented show promise for future progress in adaptive control strategies for robotic swarms.

Contributors

Agent

Created

Date Created
2017-05

134095-Thumbnail Image.png

Stability of the Human Ankle with Respect to Environmental Mechanics

Description

This study presents quantification of ankle stability as affected by environmental conditions in two degrees of freedom (DOF) with three distinct analysis techniques. Additionally, this study presents gender-specific trends for comparison. Intuitively, ankle stability decreased in less stable environments with

This study presents quantification of ankle stability as affected by environmental conditions in two degrees of freedom (DOF) with three distinct analysis techniques. Additionally, this study presents gender-specific trends for comparison. Intuitively, ankle stability decreased in less stable environments with a negative simulated stiffness. Female subjects generally suffered a greater loss of stability in moderately and highly unstable environments. Both gender groups exhibited greater stability in the sagittal plane than the frontal plane across the entire range of simulated stiffness's. Outcomes of this study are useful in the design of controllers for lower extremity physically-interactive robotics, understanding situations in which the ankle is likely to lose stability, and understanding the strengths and weaknesses of unique analysis techniques.

Contributors

Created

Date Created
2017-12

134121-Thumbnail Image.png

Design and Testing of a Low-Cost Force Sensor for a Small Robotic Manipulator

Description

This thesis details the process of developing a force feedback system for a small robotic manipulator in order to prevent damage to manipulators and the objects they are grasping, which is a desired feature in many autonomous robots. This includes

This thesis details the process of developing a force feedback system for a small robotic manipulator in order to prevent damage to manipulators and the objects they are grasping, which is a desired feature in many autonomous robots. This includes the research, design, fabrication, and testing of a custom force-sensing resistor and a custom set of jaws to implement the feedback system on. In order to complete this project, extensive research went to designing and building test beds for the commercial and custom force sensors to determine if force values could even be obtained. Then the sensors were implemented on a manipulator and were evaluated for ease of use during assembly and testing, accuracy, and repeatability of results using a test bed designed during the course of this research. Afterwards the custom jaws were designed and fabricated based on problems encountered during testing with the initial set of jaws. The new jaws were then tested on the test bed with the sensors and the force feedback system was implemented on it. The overall system was then evaluated for any current limitations and improvements that could be made in the future to further develop this research and assist with its implementation on other robots. The results of this experiment show that a low-cost force sensor that is easy to mass produce can be implemented on an autonomous robot to add force feedback capabilities to it. It is hopeful that the results from the experiments conducted are implemented on robotic manipulators so the area of force sensing technologies research can be expanded upon and improved.

Contributors

Created

Date Created
2017-12

129392-Thumbnail Image.png

Design of Ant-Inspired Stochastic Control Policies for Collective Transport by Robotic Swarms

Description

In this paper, we present an approach to designing decentralized robot control policies that mimic certain microscopic and macroscopic behaviors of ants performing collective transport tasks. In prior work, we used a stochastic hybrid system model to characterize the observed

In this paper, we present an approach to designing decentralized robot control policies that mimic certain microscopic and macroscopic behaviors of ants performing collective transport tasks. In prior work, we used a stochastic hybrid system model to characterize the observed team dynamics of ant group retrieval of a rigid load. We have also used macroscopic population dynamic models to design enzyme-inspired stochastic control policies that allocate a robotic swarm around multiple boundaries in a way that is robust to environmental variations. Here, we build on this prior work to synthesize stochastic robot attachment–detachment policies for tasks in which a robotic swarm must achieve non-uniform spatial distributions around multiple loads and transport them at a constant velocity. Three methods are presented for designing robot control policies that replicate the steady-state distributions, transient dynamics, and fluxes between states that we have observed in ant populations during group retrieval. The equilibrium population matching method can be used to achieve a desired transport team composition as quickly as possible; the transient matching method can control the transient population dynamics of the team while driving it to the desired composition; and the rate matching method regulates the rates at which robots join and leave a load during transport. We validate our model predictions in an agent-based simulation, verify that each controller design method produces successful transport of a load at a regulated velocity, and compare the advantages and disadvantages of each method.

Contributors

Agent

Created

Date Created
2014-12-01