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3. Stair Climbing using the Angular Momentum Linear Inverted Pendulum Model and Model Predictive Control

Author

Dosunmu-Ogunbi, Oluwami, Shrivastava, Aayushi, Gibson, Grant, and Grizzle, Jessy W

Subjects
Computer Science - Robotics, Electrical Engineering and Systems Science - Systems and Control
Abstract

A new control paradigm using angular momentum and foot placement as state variables in the linear inverted pendulum model has expanded the realm of possibilities for the control of bipedal robots. This new paradigm, known as the ALIP model, has shown effectiveness in cases where a robot's center of mass height can be assumed to be constant or near constant as well as in cases where there are no non-kinematic restrictions on foot placement. Walking up and down stairs violates both of these assumptions, where center of mass height varies significantly within a step and the geometry of the stairs restrict the effectiveness of foot placement. In this paper, we explore a variation of the ALIP model that allows the length of the virtual pendulum formed by the robot's stance foot and center of mass to follow smooth trajectories during a step. We couple this model with a control strategy constructed from a novel combination of virtual constraint-based control and a model predictive control algorithm to stabilize a stair climbing gait that does not soley rely on foot placement. Simulations on a 20-degree of freedom model of the Cassie biped in the SimMechanics simulation environment show that the controller is able to achieve periodic gait.

Published
2023
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4. Exploring Kinodynamic Fabrics for Reactive Whole-Body Control of Underactuated Humanoid Robots

Author

Adu-Bredu, Alphonsus, Gibson, Grant, and Grizzle, Jessy W.

Subjects
Computer Science - Robotics
Abstract

For bipedal humanoid robots to successfully operate in the real world, they must be competent at simultaneously executing multiple motion tasks while reacting to unforeseen external disturbances in real-time. We propose Kinodynamic Fabrics as an approach for the specification, solution and simultaneous execution of multiple motion tasks in real-time while being reactive to dynamism in the environment. Kinodynamic Fabrics allows for the specification of prioritized motion tasks as forced spectral semi-sprays and solves for desired robot joint accelerations at real-time frequencies. We evaluate the capabilities of Kinodynamic fabrics on diverse physically challenging whole-body control tasks with a bipedal humanoid robot both in simulation and in the real-world. Kinodynamic Fabrics outperforms the state-of-the-art Quadratic Program based whole-body controller on a variety of whole-body control tasks on run-time and reactivity metrics in our experiments. Our open-source implementation of Kinodynamic Fabrics as well as robot demonstration videos can be found at this url: https://adubredu.github.io/kinofabs.

Published
2023

6. Terrain-Adaptive, ALIP-Based Bipedal Locomotion Controller via Model Predictive Control and Virtual Constraints

Author

Gibson, Grant, Dosunmu-Ogunbi, Oluwami, Gong, Yukai, and Grizzle, Jessy

Subjects
Computer Science - Robotics, Electrical Engineering and Systems Science - Systems and Control
Abstract

This paper presents a gait controller for bipedal robots to achieve highly agile walking over various terrains given local slope and friction cone information. Without these considerations, untimely impacts can cause a robot to trip and inadequate tangential reaction forces at the stance foot can cause slippages. We address these challenges by combining, in a novel manner, a model based on an Angular Momentum Linear Inverted Pendulum (ALIP) and a Model Predictive Control (MPC) foot placement planner that is executed by the method of virtual constraints. The process starts with abstracting from the full dynamics of a Cassie 3D bipedal robot, an exact low-dimensional representation of its center of mass dynamics, parameterized by angular momentum. Under a piecewise planar terrain assumption and the elimination of terms for the angular momentum about the robot's center of mass, the centroidal dynamics about the contact point become linear and have dimension four. Importantly, we include the intra-step dynamics at uniformly-spaced intervals in the MPC formulation so that realistic workspace constraints on the robot's evolution can be imposed from step-to-step. The output of the low-dimensional MPC controller is directly implemented on a high-dimensional Cassie robot through the method of virtual constraints. In experiments, we validate the performance of our control strategy for the robot on a variety of surfaces with varied inclinations and textures.

Published
2021
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18. Understanding the challenges associated with finding and accessing restricted data in Canada: a mixed methods study

Author

Read, Kevin B., Gibson, Grant, Leahey, Amber, Peterson, Lynn, Rutley, Sarah, Shi, Julie, Smith, Victoria, and Stathis, Kelly

Abstract

Data that are restricted are historically challenging for researchers to find and even more difficult to access. While efforts to support open data have expanded in Canada, the same cannot be said for restricted data. To better understand the landscape of restricted data in Canada, this study aimed to accomplish two primary goals: (1) identify data sources where data were restricted and (2) assess a subset of health sciences data sources to determine how well they make their data discoverable and accessible. Our study identified 137 Canadian data sources, where 48 health sciences sources were evaluated for discoverability/accessibility. Data sources received poor grades with respect to data discovery due to a lack of metadata standards (38/48, 79%), an inability to find datasets through searching and browsing (32/46, 70%), and a lack of data documentation to support reuse (27/48, 56%). The absence of pricing information (31/48, 65%) and opaque dataset restrictions (25/48, 52%) were identified as key barriers to the data access request process. This study highlights significant room for improvement with respect to improving the discovery of and access to restricted data in Canada and makes recommendations for how to better support restricted data sources on a national scale.

Published
2024
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21. Men's experiences of living with Parkinson's disease

Author

Gibson, Grant

Subjects
362.196833
Abstract

The goal of this thesis is to explore men's experiences of living with Parkinson's Disease, a progressive neurological disorder predominantly affecting men in older age. Research into PO has been predominantly informed by a biomedical, neurological model. Although bringing significant benefit to PO's treatment, this approach fails to adequately consider the question of PO's lived experience, leading to major gaps in our knowledge of the condition and its effects on sufferer's lives. In addition, although making up the majority of sufferers, the specific needs of older men with PO have been neglected within wider research into PD. Using a phenomenological methodology concerned with men's experience of the lifeworld, and how this experience is influenced by gender and ageing, this study used narrative interviews combined with a photographic elicitation approach to ascertain the lived experiences of 15 men, from a number of different areas and of differing ages. The findings of this thesis indicate that PO is more than simply a movement disorder. Instead it should be understood as a condition which disrupts the unity of the body, self and world. PO brings about particular challenges to men's experience of the lived body and lived time, distancing them from a shared experience of the lifeworld. Men also found ways to try and cope with their PO, but these approaches had to continually change as men moved through the illness. Finally, men's lived experience was intertwined with ageing and masculinity. PO posed a threat to men's masculine status; however men could also use masculinity as a resource to understand PO's various effects on their lives. How well men could respond to these changes had key implications for their continued well-being and quality of life, therefore giving insights into how future PO services can be improved. ThiS thesis concludes by making recommendations for the development of person and gender sensitive services in PD. These include paying greater attention to PO's lived experience and the stories men tell of their illness; engaging with the problems men identify that PO causes in their lives; and the greater provision of forms of information and psychosocial support which recognises all of PO's effects; including non-motor symptoms, psychosocial consequences and medication induced side effects.

Published
2013
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28. Canadian data source identification and evaluation datasets

Author

Read, Kevin, Gibson, Grant, Leahey, Amber, Peterson, Lynn, Rutley, Sarah, Smith, Victoria, Stathis, Kelly, and Shi, Julie

Abstract

This page contains all datasets generated over the course of a project aimed to identify and evaluate restricted health data sources in Canada for the purposes of improving the discovery of, and access to research data.

Published
2022
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29. Access-Limited Data Source Grading Rubric

Author

Read, Kevin, Gibson, Grant, Leahey, Amber, Peterson, Lynn, Rutley, Sarah, Smith, Victoria, and Stathis, Kelly

Abstract

A grading rubric for evaluating access-limited data sources based on their ability to make their data clearly discoverable and accessible. This grading rubric was applied to 53 Canadian health data sources.

Published
2022
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35. “It Is Part of Belonging”: Walking Groups to Promote Social Health amongst People Living with Dementia

Author

Paths for All, Robertson, Jane M., Gibson, Grant, Pemble, Catherine, Harrison, Rog, Strachan, Kim, Thorburn, Sheila, Paths for All, Robertson, Jane M., Gibson, Grant, Pemble, Catherine, Harrison, Rog, Strachan, Kim, and Thorburn, Sheila

Abstract

People with dementia often report experiencing a ‘shrinking world’ connected with reduced opportunities to access physical and social spaces. This article applies the framework of social health (Dröes et al., 2017; Huber et al., 2011) as a theoretical lens through which to consider how inclusive walking groups can facilitate access to places and spaces to support people with dementia to remain connected in their communities. Findings are reported from walking interviews and focus group discussions with people with dementia, family carers, volunteers and walk leaders who participated in a national programme of dementia-friendly walking groups in Scotland. Thematic analysis of the data demonstrates that participation has a positive impact on social health, supporting people living with dementia to fulfil their potential, to engage in meaningful activity and to manage both their condition and their wider lives. Benefits include providing a context for continuing social participation and relationships for people with dementia and family carers. Additionally, groups provide a safe space where people with dementia can walk with autonomy and help to reinforce a sense of capacity and agency. Wider implications include the role of walking groups in fostering interdependencies between people with dementia and their wider communities by promoting an enabling ethos of dementia ‘inclusiveness.’ The benefits of developing an inclusive and supportive approach to involving people living with dementia in walking groups could extend more broadly to the wider community, with such initiatives acting as a catalyst for growing levels of social participation.

Published
2020

36. 'It Is Part of Belonging': Walking Groups to Promote Social Health amongst People Living with Dementia

Author

Robertson, Jane M., Gibson, Grant, Pemble, Catherine, Harrison, Rog, Strachan, Kim, Thorburn, Sheila, Robertson, Jane M., Gibson, Grant, Pemble, Catherine, Harrison, Rog, Strachan, Kim, and Thorburn, Sheila

Abstract

People with dementia often report experiencing a ‘shrinking world’ connected with reduced opportunities to access physical and social spaces. This article applies the framework of social health (Dröes et al., 2017; Huber et al., 2011) as a theoretical lens through which to consider how inclusive walking groups can facilitate access to places and spaces to support people with dementia to remain connected in their communities. Findings are reported from walking interviews and focus group discussions with people with dementia, family carers, volunteers and walk leaders who participated in a national programme of dementia-friendly walking groups in Scotland. Thematic analysis of the data demonstrates that participation has a positive impact on social health, supporting people living with dementia to fulfil their potential, to engage in meaningful activity and to manage both their condition and their wider lives. Benefits include providing a context for continuing social participation and relationships for people with dementia and family carers. Additionally, groups provide a safe space where people with dementia can walk with autonomy and help to reinforce a sense of capacity and agency. Wider implications include the role of walking groups in fostering interdependencies between people with dementia and their wider communities by promoting an enabling ethos of dementia ‘inclusiveness.’ The benefits of developing an inclusive and supportive approach to involving people living with dementia in walking groups could extend more broadly to the wider community, with such initiatives acting as a catalyst for growing levels of social participation.

Published
2020

37. Optimum activity of the phosphofructokinase from Ascaris suum requires more than one metal ion

Author

Gibson, Grant E., Harris, Ben G., and Cook, Paul F.

Subjects
Ascaris -- Genetic aspects, Phosphorylation -- Analysis, Fructosediphosphate aldolase -- Chemical properties, Biological sciences, Chemistry
Abstract

Initial rate and isotope partitioning studies are carried out as a function of Mg(super 2+) in the absence and presence of fructose 2,6-bisphosphate (F26P2) in order to determine whether more than one Mg(super 2+) is required for optimum activity of phosphofructokinase (PFK). The results show that the kinetic mechanism changes from ordered to random as the Mg(super 2+) concentration decreases and in the presence of F26P2, the mechanism becomes random as a result of an increase in the affinity of F6P (fructose 6-phosphate).

Published
2006

38. The scope for qualitative methods in research and clinical trials in dementia

Author

Gibson, Grant, Timlin, Alison, Curran, Stephen, and Wattis, John

Subjects
Methodology -- Evaluation, Aged patients -- Care and treatment, Dementia -- Research, Clinical trials -- Usage, Alzheimer's disease -- Research, Health, Psychology and mental health, Seniors, Social sciences
Published
2004

40. 'It gives you a reason to be in this world': the interdependency of communities, environments and social justice for quality of life in older people.

Author

Robertson, Jane M., Gibson, Grant, Greasley-Adams, Corinne, McCall, Vikki, Gibson, Joan, Mason-Duff, Janice, and Pengelly, Ro

Subjects
*WELL-being, *FOCUS groups, *SOCIAL justice, *ECOLOGY, *HUMAN services programs, *QUALITY of life, *COMMUNITY-based social services, *ACTION research, *POLICY sciences, *SECONDARY analysis
Abstract

Research regarding quality of life among older people has predominantly focused on functional elements experienced at individual or dyadic level despite the complex interplay of factors that contribute to quality of life. Perspectives which explore interdependencies within communities and the intersecting environments in which older people exercise agency have seen less study. They do, however, play an important role in influencing quality of life as experienced by older people across community settings. Qualitative data from a co-produced study of dimensions influencing quality of life in older people was subjected to secondary analysis using a critical human ecological approach. Findings demonstrate the importance of community interdependencies in supporting individual quality of life, the expression of active agency to foster quality of life within and across communities, and the importance of state infrastructures and service provision within these interdependencies. This article argues for a movement beyond functional conceptualisations of quality of life towards the inclusion of perspectives regarding communal wellbeing, alongside the role differing types of community play in influencing quality of life. Through developing conceptions of quality of life in social relations and community cohesion, in particular how quality of life is influenced by perceptions of solidarity and social justice including across generations, assessing quality of life at community level will assist in driving cultural change in policy making and practice. [ABSTRACT FROM AUTHOR]

Published
2022
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45. Life at Home and Technology with Dementia

Author

Gibson, Grant, Astell, Arlene, Smith, Sarah Kate, and Joddrell, Phil

Abstract

First paragraph: Enabling people with dementia to live independently in their own homes is a key objective of contemporary dementia care policy and practice. Frequently referred to as ‘ageing in place’, current health care policy across many western countries focuses upon ensuring people with dementia can stay at home as their dementia progresses, thereby delaying, reducing or avoiding the use of state services such as residential or nursing care (Brittain et al 2010; Kenner 2008; Roberts et al 2012; Buffel et al 2012). Such policy objectives typically have the support of older people themselves, with the majority routinely stating that they would prefer to remain at home for as long as possible (Oldman 2003; Lui et al, 2009). In order to support this objective, assistive technologies have been posited as a means to support people with dementia to remain at home (Sixsmith & Sixsmith 2008). Products defined as assistive technology can include a whole range of mobility aids and household adaptations, however in the context of people living with dementia, the term assistive technology is most often associated with electronic devices or services which can monitor a person’s activities, or products that can assist a person with daily functions (Gibson et al 2016).

Published
2019

47. HLA-omics and cancer biomarkers: emerging tools and technologies for the medical laboratory

Author

Pogue, Gregory P., Gibson, Grant, and Capra, J. Donald

Subjects
Histocompatibility antigens -- Analysis, HLA histocompatibility antigens -- Analysis, Cancer -- Care and treatment
Abstract

CONTINUING EDUCATION To earn CEUs, see current test at www.mlo-online.com under the CE Tests tab. LEARNING OBJECTIVES Upon completion of this article, the reader will be able to recognize: 1. [...]

Published
2008

48. A stringent test for the nucleotide switch mechanism of carbamoyl phosphate synthetase

Author

Raushel, Frank M., Mullins, Leisha S., and Gibson, Grant E.

Subjects
Oxygen -- Research, Adenosine triphosphatase -- Research, Phosphates -- Research, Bicarbonates -- Research, Biosynthesis -- Research, Glutamine -- Research, Biological sciences, Chemistry
Abstract

Experiments were performed to measure the isotopic oxyen exchange between solvent water and bicarbonate during the bicarbonate-dependent ATPase reaction and the overall biosynthetic reaction catalyzed by carbamoyl phosphate synthase. Results showed that in the absence of added glutamine, an oxygen atom from bicarbonate exchanged with solvent water during every turnover of the bicarbonate-dependent ATPase reaction. Moreover, the reaction was found to be fully inhibited upon the addition of glutamine and the formation of carbamoyl phosphate.

Published
1998

49. Factors affecting the corrosion fatigue life in nickel based superalloys for disc applications

Author

Rosier Hollie, Perkins Karen, Girling Andrew, Leggett Jonathan, and Gibson Grant

Subjects
Engineering (General). Civil engineering (General), TA1-2040
Abstract

The nickel based superalloy 720Li is employed in the gas turbine due to its mechanical performance at elevated temperature. A comprehensive assessment of the materials behaviour under representative service conditions is reported to address the drive for ever increasing temperatures and more arduous environmental exposure. Fatigue experiments have been performed in an air and air/SOx environment at 700 ∘C containing a mixed salt as a contaminant. There is an intimate relationship between local salt level (flux), stress level and stress state, i.e. static or cyclic. The interaction with these variables with the work hardened layer present on the surface of all tested specimens as a result of the shot peening process directly affects the crack initiation process. If specific conditions of environment and stress are achieved, a significant reduction in fatigue life is observed.

Published
2014
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50. Isotope partitioning with Ascaris suum phosphofructokinase is consistent with an ordered kinetic mechanism

Author

Gibson, Grant E., Harris, Ben G., and Cook, Paul F.

Subjects
Enzyme kinetics -- Research, Enzymes -- Regulation, Biological sciences, Chemistry
Abstract

The kinetic mechanism of phosphofructokinase (PFK) from the parasitic helminth Ascaris suum is examined using isotope partitioning. Results indicate that the PFK has a steady-state ordered mechanism. Initial velocity studies provide further proof of this kinetic mechanism as they show that the mechanism is predominately steady-state. The Ascaris suum PFK shows allosteric substrate inhibition by MgATP as well as homotropic cooperativity with F6P.

Published
1996

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