Generalized Two Color Map Theorem -- Complete Theorem of Robust Gait Plan for a Tilt-rotor

Gait plan is a procedure that is typically applied on the ground robots, e.g., quadrupedal robots; the tilt-rotor, a novel type of quadrotor with eight inputs, is not one of them. While controlling the tilt-rotor relying on feedback linearization, the tilting angles (inputs) are expected to change over-intensively, which may not be expected in the application. To help suppress the intensive change in the tilting angles, a gait plan procedure is introduced to the tilt-rotor before feedback linearization. The tilting angles are specified with time in advance by users rather than given by the control rule. However, based on this scenario, the decoupling matrix in feedback linearization can be singular for some attitudes, combinations of roll angle and pitch angle. It hinders the further application of the feedback linearization. With this concern, Two Color Map Theorem is established to maximize the acceptable attitude region, where the combinations of roll and pitch will give an invertible decoupling matrix. That theorem, however, over-restricts the choice of the tilting angles, which can rule out some feasible robust gaits. This paper gives the generalized Two Color Map Theorem; all the robust gaits can be found based on this generalized theorem. The robustness of three gaits that satisfy this generalized Two Color Map Theorem (while violating Two Color Map Theorem) are analyzed. The results show that Generalized Two Color Map Theorem completes the search for the robust gaits for a tilt-rotor

Advanced Feedback Linearization Control for Tiltrotor UAVs: Gait Plan, Controller Design, and Stability Analysis

Three challenges, however, can hinder the application of Feedback Linearization: over-intensive control signals, singular decoupling matrix, and saturation. Activating any of these three issues can challenge the stability proof. To solve these three challenges, first, this research proposed the drone gait plan. The gait plan was initially used to figure out the control problems in quadruped (four-legged) robots; applying this approach, accompanied by Feedback Linearization, the quality of the control signals was enhanced. Then, we proposed the concept of unacceptable attitude curves, which are not allowed for the tiltrotor to travel to. The Two Color Map Theorem was subsequently established to enlarge the supported attitude for the tiltrotor. These theories were employed in the tiltrotor tracking problem with different references. Notable improvements in the control signals were witnessed in the tiltrotor simulator. Finally, we explored the control theory, the stability proof of the novel mobile robot (tilt vehicle) stabilized by Feedback Linearization with saturation. Instead of adopting the tiltrotor model, which is over-complicated, we designed a conceptual mobile robot (tilt-car) to analyze the stability proof. The stability proof (stable in the sense of Lyapunov) was found for a mobile robot (tilt vehicle) controlled by Feedback Linearization with saturation for the first time. The success tracking result with the promising control signals in the tiltrotor simulator demonstrates the advances of our control method. Also, the Lyapunov candidate and the tracking result in the mobile robot (tilt-car) simulator confirm our deductions of the stability proof. These results reveal that these three challenges in Feedback Linearization are solved, to some extents.Comment: Doctoral Thesis at The University of Toky

Modeling, Analysis and Control of Underwater Vehicle SROV

A new type of Remotely Operated Vehicle (ROV) has been designed by Marin Mätteknik (MMT) in cooperation with Reach Subsea and Kystdesign AS; the Surveyor ROV. Although MMT is successfully using the SROV in day-to-day operations, no mathematical model describing the system has previously been derived. In this thesis project, a mathematical model describing the SROV is developed through system identification techniques. Experiments to facilitate parameter estimation of the model are designed and consequently performed. The gathered data sets are investigated to determine how well they are suited for parameter estimation. Estimation of the continuous-time model parameters are carried out using a Kalman filter running on the input-output data obtained through the experiments. Comparisons between this method and results obtained through a subspacebased identification Matlab method are performed. Model validation is carried out using numerous performance measures. The thesis has shown that a coupled LPV model may be a feasible approach to the modeling problem, and also makes suggestions that could possiblyimprove on the results. As an alternative to the current control system, simulations of closed-loop responses of the identified system model using a Model Predictive Control (MPC) structure are undertaken and presented. The simulations show that good performance is achievable using the MPC lgorithm. Noticeably, the current control system has difficulties attenuating deviations from angular velocity set points. The MPC scheme has been shown to effectively suppress such control errors in simulations

Produktutvikling av ROV ramme, elektronikkhus og flyter

Denne bachelpor oppgaven har som mål å designe, produsere og konstruere en ROV-ramme, elektronikk hus og en vitenskapelig flyter ved hjelp av produktutviklingsprosessen. Oppgaven er en del av et større prosjektsamarbeid med åtte andre bacheloroppgaver fra tre fagområder knyttet sammen gjennom studentorganisasjonen UiS Subsea. De endelige produktene fra det overordnede prosjektet vil konkurrere i TAC- og MATE-challenge i juni 2023. UiS Subsea er en organisasjon med faste etiske retningslinjer og et begrenset budsjett. Derfor dreier oppgaven seg om å minimere kostnadene, miljøpåvirkningen og tidsskjemaet for hver beslutning som er involvert i produkt- og produktutviklingsprosessen, samtidig som de tar hensyn til de andre delproduktene i oppgavene. Produktutvikling er en metode som er konstruert for å designe og utvikle nye produkter på en tidseffektiv og kostnadseffektiv måte. I denne oppgaven blir de de viktigste fasene implementert: planlegging, konseptutvikling, systemdesign på overordnet nivå, detaljdesign og testing og forbedring, med alle fasene som inneholder mindre delfaser og trinn relevante for produktet. Ettersom UiS Subsea allerede hadde fullført deler av planleggingsfasen før prosjektstart, handlet denne fasen om å undersøke og forske på de ulike målene og begrensningene de ulike interessentene hadde for prosjektet, inkludert UiS Subsea selv og MATE ROV-konkurransen. Denne forskningen gjorde det enklere og mer tidseffektivt å utvikle konseptene, ettersom behovene og forventningene ble utforsket og etablert. Konsepter kunne dermed effektivt utvikles, forkastes og velges basert på målspecifikasjonen, beregninger og simuleringer. Systemdesignet kunne deretter fokusere på å koble sammen og montere alle delene som trengs til et fungerende endelig produkt. Etter å ha utviklet en fungerende montering på systemnivå, fokuserte detaljdesignet på endelige forbedringer, fastsettelse av endelige dimensjoner gjennom analyse og simuleringer, valg av materiale for hver komponent, og beregninger knyttet til oppdrift og stabilitet. Alle valg av materiale og endelige dimensjoner ble verifisert for å være sterke nok til å tåle alle forventede krefter og belastninger, samtidig som de oppfylte produktets krav til styrke, oppdrift, miljøpåvirkning og kostnader. Når det ble verifisert, ble de endelige delene produsert, montert og gjennomgikk ikke-destruktiv testing. Basert på resultatene fra testene, ble forbedringer og endringer gjort for å produsere best mulig produkt. Alt i alt hjalp produktutviklingsprosessen med planlegging, koordinering, kreativitet og den generelle strukturen i prosjektet, noe som var til nytte i et tverrfaglig prosjekt. Den standardiserte produktutviklingsprosessen hadde mange trinn som ikke var nødvendige for hvert prosjekt, så hver bedrift og hvert prosjekt bør velge trinnene som passer best for deres prosjekt for å utnytte metoden best mulig. For denne avhandlingen innebar det å utlede egne mål og målsettinger for hver fase basert på innholdet i den standardiserte prosessen og streve for å oppfylle disse målene. De endelige produktene var tilfredsstillende totalt sett, presterte godt under testing og fullførte nødvendige oppgaver for å kvalifisere seg for MATE-konkurransen. Produktene er designet og passer godt for neste års avgangsstudenter for å oppgradere og forbedre produktene.This thesis aspires to design, manufacture and construct a ROV frame, an electronic enclosure, and a scientific float by using the product development process. The thesis is part of a larger project collaboration with eight other bachelor theses from three disciplines connected through the student organization UiS Subsea. The final products of the overall project will compete in TAC and MATE challenge in June 2023. UiS Subsea is an organization with set moral guidelines and a limited budget. Therefore the thesis revolves around minimizing the cost, environmental impact, and timetable of every decision involved in the product and product development process while accommodating the other theses sub-products. Product development is a method constructed for designing and developing new products in a timely and cost-efficient way. This thesis includes its main phases: planning, concept development, system level design, detail level design, and testing and refinement, with all phases containing smaller sub-phases and steps relevant to the product. As UiS Subsea already had completed parts of the planning phase before the start of the project, this phase revolved around investigating and researching the different targets and limitations the different stakeholders had for the project, including UiS Subsea themselves and the MATE ROV competition. This research made the concept development phase easier and time efficient since the needs and expectations were explored and established. Concepts could therefore be effectively created, discarded, and selected based on the target specification, calculations, and simulations. The system level design could thereby focus on connecting and assembling all the parts needed together into a functioning final product. After developing a functioning assembly in system level design, the detail design focused on final improvements, setting final dimensions through analysis and simulations, material choice for each component, and calculations surrounding buoyancy and stability. All material choices and final dimensions were verified to be strong enough to withstand all expected forces and loads while fulfilling the product’s strength, buoyancy, environmental and cost requirements. When verified, the final parts were manufactured, assembled, and underwent non-destructive testing. Based on the results of the tests and improvements, altercations were made to the final products. Overall, the product development process helped with planning, coordination, creativity, and overall structure of the project, which were beneficial during an interdisciplinary project. The standard product development process had many steps that were not necessary for every project, so each company and project should select the steps best suited to their project for the best utilization of the method. For this thesis, that included deriving each phase’s own targets and goals based on the standard process’s contents and striving to fulfill these goals. The final products were satisfactory overall, did well during testing, and completed the necessary tasks to qualify for the MATE competition. However, improvements and altercations could always be made to enhance the products further. The products are designed and well-suited for next year’s graduates to upgrade and improve

Produktutvikling av ROV ramme, elektronikk hus og flyter

Denne bachelpor oppgaven har som mål å designe, produsere og konstruere en ROV-ramme, elektronikk hus og en vitenskapelig flyter ved hjelp av produktutviklingsprosessen. Oppgaven er en del av et større prosjektsamarbeid med åtte andre bacheloroppgaver fra tre fagområder knyttet sammen gjennom studentorganisasjonen UiS Subsea. De endelige produktene fra det overordnede prosjektet vil konkurrere i TAC- og MATE-challenge i juni 2023. UiS Subsea er en organisasjon med faste etiske retningslinjer og et begrenset budsjett. Derfor dreier oppgaven seg om å minimere kostnadene, miljøpåvirkningen og tidsskjemaet for hver beslutning som er involvert i produkt- og produktutviklingsprosessen, samtidig som de tar hensyn til de andre delproduktene i oppgavene. Produktutvikling er en metode som er konstruert for å designe og utvikle nye produkter på en tidseffektiv og kostnadseffektiv måte. I denne oppgaven blir de de viktigste fasene implementert: planlegging, konseptutvikling, systemdesign på overordnet nivå, detaljdesign og testing og forbedring, med alle fasene som inneholder mindre delfaser og trinn relevante for produktet. Ettersom UiS Subsea allerede hadde fullført deler av planleggingsfasen før prosjektstart, handlet denne fasen om å undersøke og forske på de ulike målene og begrensningene de ulike interessentene hadde for prosjektet, inkludert UiS Subsea selv og MATE ROV-konkurransen. Denne forskningen gjorde det enklere og mer tidseffektivt å utvikle konseptene, ettersom behovene og forventningene ble utforsket og etablert. Konsepter kunne dermed effektivt utvikles, forkastes og velges basert på målspecifikasjonen, beregninger og simuleringer. Systemdesignet kunne deretter fokusere på å koble sammen og montere alle delene som trengs til et fungerende endelig produkt. Etter å ha utviklet en fungerende montering på systemnivå, fokuserte detaljdesignet på endelige forbedringer, fastsettelse av endelige dimensjoner gjennom analyse og simuleringer, valg av materiale for hver komponent, og beregninger knyttet til oppdrift og stabilitet. Alle valg av materiale og endelige dimensjoner ble verifisert for å være sterke nok til å tåle alle forventede krefter og belastninger, samtidig som de oppfylte produktets krav til styrke, oppdrift, miljøpåvirkning og kostnader. Når det ble verifisert, ble de endelige delene produsert, montert og gjennomgikk ikke-destruktiv testing. Basert på resultatene fra testene, ble forbedringer og endringer gjort for å produsere best mulig produkt. Alt i alt hjalp produktutviklingsprosessen med planlegging, koordinering, kreativitet og den generelle strukturen i prosjektet, noe som var til nytte i et tverrfaglig prosjekt. Den standardiserte produktutviklingsprosessen hadde mange trinn som ikke var nødvendige for hvert prosjekt, så hver bedrift og hvert prosjekt bør velge trinnene som passer best for deres prosjekt for å utnytte metoden best mulig. For denne avhandlingen innebar det å utlede egne mål og målsettinger for hver fase basert på innholdet i den standardiserte prosessen og streve for å oppfylle disse målene. De endelige produktene var tilfredsstillende totalt sett, presterte godt under testing og fullførte nødvendige oppgaver for å kvalifisere seg for MATE-konkurransen. Produktene er designet og passer godt for neste års avgangsstudenter for å oppgradere og forbedre produktene.This thesis aspires to design, manufacture and construct a ROV frame, an electronic enclosure, and a scientific float by using the product development process. The thesis is part of a larger project collaboration with eight other bachelor theses from three disciplines connected through the student organization UiS Subsea. The final products of the overall project will compete in TAC and MATE challenge in June 2023. UiS Subsea is an organization with set moral guidelines and a limited budget. Therefore the thesis revolves around minimizing the cost, environmental impact, and timetable of every decision involved in the product and product development process while accommodating the other theses sub-products. Product development is a method constructed for designing and developing new products in a timely and cost-efficient way. This thesis includes its main phases: planning, concept development, system level design, detail level design, and testing and refinement, with all phases containing smaller sub-phases and steps relevant to the product. As UiS Subsea already had completed parts of the planning phase before the start of the project, this phase revolved around investigating and researching the different targets and limitations the different stakeholders had for the project, including UiS Subsea themselves and the MATE ROV competition. This research made the concept development phase easier and time efficient since the needs and expectations were explored and established. Concepts could therefore be effectively created, discarded, and selected based on the target specification, calculations, and simulations. The system level design could thereby focus on connecting and assembling all the parts needed together into a functioning final product. After developing a functioning assembly in system level design, the detail design focused on final improvements, setting final dimensions through analysis and simulations, material choice for each component, and calculations surrounding buoyancy and stability. All material choices and final dimensions were verified to be strong enough to withstand all expected forces and loads while fulfilling the product’s strength, buoyancy, environmental and cost requirements. When verified, the final parts were manufactured, assembled, and underwent non-destructive testing. Based on the results of the tests and improvements, altercations were made to the final products. Overall, the product development process helped with planning, coordination, creativity, and overall structure of the project, which were beneficial during an interdisciplinary project. The standard product development process had many steps that were not necessary for every project, so each company and project should select the steps best suited to their project for the best utilization of the method. For this thesis, that included deriving each phase’s own targets and goals based on the standard process’s contents and striving to fulfill these goals. The final products were satisfactory overall, did well during testing, and completed the necessary tasks to qualify for the MATE competition. However, improvements and altercations could always be made to enhance the products further. The products are designed and well-suited for next year’s graduates to upgrade and improve

Produktutvikling av ROV ramme, elektronikkhus og float

Denne bachelpor oppgaven har som mål å designe, produsere og konstruere en ROV-ramme, elektronikk hus og en vitenskapelig flyter ved hjelp av produktutviklingsprosessen. Oppgaven er en del av et større prosjektsamarbeid med åtte andre bacheloroppgaver fra tre fagområder knyttet sammen gjennom studentorganisasjonen UiS Subsea. De endelige produktene fra det overordnede prosjektet vil konkurrere i TAC- og MATE-challenge i juni 2023. UiS Subsea er en organisasjon med faste etiske retningslinjer og et begrenset budsjett. Derfor dreier oppgaven seg om å minimere kostnadene, miljøpåvirkningen og tidsskjemaet for hver beslutning som er involvert i produkt- og produktutviklingsprosessen, samtidig som de tar hensyn til de andre delproduktene i oppgavene. Produktutvikling er en metode som er konstruert for å designe og utvikle nye produkter på en tidseffektiv og kostnadseffektiv måte. I denne oppgaven blir de de viktigste fasene implementert: planlegging, konseptutvikling, systemdesign på overordnet nivå, detaljdesign og testing og forbedring, med alle fasene som inneholder mindre delfaser og trinn relevante for produktet. Ettersom UiS Subsea allerede hadde fullført deler av planleggingsfasen før prosjektstart, handlet denne fasen om å undersøke og forske på de ulike målene og begrensningene de ulike interessentene hadde for prosjektet, inkludert UiS Subsea selv og MATE ROV-konkurransen. Denne forskningen gjorde det enklere og mer tidseffektivt å utvikle konseptene, ettersom behovene og forventningene ble utforsket og etablert. Konsepter kunne dermed effektivt utvikles, forkastes og velges basert på målspecifikasjonen, beregninger og simuleringer. Systemdesignet kunne deretter fokusere på å koble sammen og montere alle delene som trengs til et fungerende endelig produkt. Etter å ha utviklet en fungerende montering på systemnivå, fokuserte detaljdesignet på endelige forbedringer, fastsettelse av endelige dimensjoner gjennom analyse og simuleringer, valg av materiale for hver komponent, og beregninger knyttet til oppdrift og stabilitet. Alle valg av materiale og endelige dimensjoner ble verifisert for å være sterke nok til å tåle alle forventede krefter og belastninger, samtidig som de oppfylte produktets krav til styrke, oppdrift, miljøpåvirkning og kostnader. Når det ble verifisert, ble de endelige delene produsert, montert og gjennomgikk ikke-destruktiv testing. Basert på resultatene fra testene, ble forbedringer og endringer gjort for å produsere best mulig produkt. Alt i alt hjalp produktutviklingsprosessen med planlegging, koordinering, kreativitet og den generelle strukturen i prosjektet, noe som var til nytte i et tverrfaglig prosjekt. Den standardiserte produktutviklingsprosessen hadde mange trinn som ikke var nødvendige for hvert prosjekt, så hver bedrift og hvert prosjekt bør velge trinnene som passer best for deres prosjekt for å utnytte metoden best mulig. For denne avhandlingen innebar det å utlede egne mål og målsettinger for hver fase basert på innholdet i den standardiserte prosessen og streve for å oppfylle disse målene. De endelige produktene var tilfredsstillende totalt sett, presterte godt under testing og fullførte nødvendige oppgaver for å kvalifisere seg for MATE-konkurransen. Produktene er designet og passer godt for neste års avgangsstudenter for å oppgradere og forbedre produktene.This thesis aspires to design, manufacture and construct a ROV frame, an electronic enclosure, and a scientific float by using the product development process. The thesis is part of a larger project collaboration with eight other bachelor theses from three disciplines connected through the student organization UiS Subsea. The final products of the overall project will compete in TAC and MATE challenge in June 2023. UiS Subsea is an organization with set moral guidelines and a limited budget. Therefore the thesis revolves around minimizing the cost, environmental impact, and timetable of every decision involved in the product and product development process while accommodating the other theses sub-products. Product development is a method constructed for designing and developing new products in a timely and cost-efficient way. This thesis includes its main phases: planning, concept development, system level design, detail level design, and testing and refinement, with all phases containing smaller sub-phases and steps relevant to the product. As UiS Subsea already had completed parts of the planning phase before the start of the project, this phase revolved around investigating and researching the different targets and limitations the different stakeholders had for the project, including UiS Subsea themselves and the MATE ROV competition. This research made the concept development phase easier and time efficient since the needs and expectations were explored and established. Concepts could therefore be effectively created, discarded, and selected based on the target specification, calculations, and simulations. The system level design could thereby focus on connecting and assembling all the parts needed together into a functioning final product. After developing a functioning assembly in system level design, the detail design focused on final improvements, setting final dimensions through analysis and simulations, material choice for each component, and calculations surrounding buoyancy and stability. All material choices and final dimensions were verified to be strong enough to withstand all expected forces and loads while fulfilling the product’s strength, buoyancy, environmental and cost requirements. When verified, the final parts were manufactured, assembled, and underwent non-destructive testing. Based on the results of the tests and improvements, altercations were made to the final products. Overall, the product development process helped with planning, coordination, creativity, and overall structure of the project, which were beneficial during an interdisciplinary project. The standard product development process had many steps that were not necessary for every project, so each company and project should select the steps best suited to their project for the best utilization of the method. For this thesis, that included deriving each phase’s own targets and goals based on the standard process’s contents and striving to fulfill these goals. The final products were satisfactory overall, did well during testing, and completed the necessary tasks to qualify for the MATE competition. However, improvements and altercations could always be made to enhance the products further. The products are designed and well-suited for next year’s graduates to upgrade and improve

Optimisation of docking locations for remotely operated vehicles.

This thesis describes work aimed at developing practical methods for determining the best docking locations for an underwater remotely operated vehicle (ROV) when inspecting an offshore platform. ROVs are used extensively in the offshore oil and gas industry to conduct a large variety of intervention tasks such as visual inspection, operational monitoring, equipment installation and operation, debris recovery, and so on. However, they have found only limited use in the more difficult tasks such as the detailed inspection of complex weld geometries. These complex welds are, however, found extensively in the construction of the majority of offshore structures and platforms ('oil rigs'). Furthermore, there is a safety requirement to have them inspected regularly since failure of these welds can potentially lead to catastrophic failure of the structures, the majority of which are manned. A number of specialist ROV systems have been developed that are able to attach onto platform structures and use their manipulators to conduct inspection. However, due to the short reach of the manipulators and the complex geometry of the welds (often encumbered with protruding pipes and other fittings) the success of any inspection is crucially dependent on a good initial choice of ROV docking position. This thesis will describe the problems and current manual planning methods, and then detail the development of two new methods for automated optimisation of docking positions - firstly using neural networks, and secondly using more conventional numerical processing. This thesis will also review related work in the field, such as the development of neural networks and their applications in the general offshore environment and in the control of ROVs and robot manipulator arms, and other approaches to ROV docking. It will further describe the use of the system developed here for planning docking positions on example commercial ROV inspection work programmes

BALLET: Balloon Locomotion for Extreme Terrain

This report documents the work performed in our investigation into the BALLET (Balloon Locomotion for Extreme Terrain) concept. We focused on four areas in this Phase I effort. They were 1) identifying the science targets and objectives with the corresponding requisite instrumentation and operational capabilities that could be achieved with a BALLET mission, 2) developing an architecture for the deployment and operation of this concept for a future mission to a planetary body, 3) analyzing a parametric physical model of BALLET under the environmental conditions of Mars, Titan and Earth to determine its feasibility, and 4) developing and demonstrating coordinated control of the BALLET mobility system to enable locomotion over rugged terrain. The results of our investigations in these focus areas are documented in the following sections. A paper summarizing the preliminary results from this study has been accepted for publication and presentation at the 2019 IEEE Aerospace Conference [Nayar, 2019]