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Design and experimental analysis of an adjustable geometry vehicle with independent drive-steering for energy efficiency optimisation
(The University of Waikato, 2026) Shang, Ray; McGuinness, Benjamin
Agricultural vehicles operating in orchard and pasture environments are required to perform frequent low-speed turning manoeuvres on uneven, grass-covered terrain - conditions under which steering strategy and vehicle geometry are major determinants of energy consumption. Despite a well-developed body of mathematical models predicting these effects, experimental validation has remained limited due to the absence of physical platforms that combine adjustable wheelbase, adjustable track width, and switchable steering strategies within a single vehicle. This thesis addresses that gap through the design, construction, and experimental evaluation of a fully electric, adjustable-geometry agricultural robot platform. The vehicle employs four independent in-wheel drive-steer modules, each integrating a brushless DC drive motor and a dedicated steering motor, mounted at the corners of a reconfigurable semi-monocoque chassis. Both wheelbase and track width can be independently adjusted across three values - 400 mm, 600 mm, and 800 mm - yielding a full 3×3 factorial matrix of nine geometric configurations. Six distinct steering modes are supported: two-wheel steering arc turn (R = 1.5 m), four-wheel steering arc turn (R = 1.5 m), skid-steer arc turn (R = 1.5 m), two-wheel point turn (R = 0), four-wheel point turn (R = 0), and skid-steer point turn (R = 0). Motor current is continuously logged at all eight drive and steer motor channels via a dedicated data acquisition system, enabling direct electrical energy quantification as E = Σ|I|·V·Δt. Controlled field experiments were conducted on two terrain conditions representative of New Zealand orchard and pasture environments: near-horizontal grass (mean inclination 0.216°) and a steep grass slope (mean inclination 17.618°). On flat terrain, all nine geometric configurations were tested across all six steering modes. On the slope, three full-width-track configurations (B = 800 mm) were evaluated for safety. Experimental results demonstrate that wheelbase L is the dominant geometric parameter governing turning energy consumption, with strong positive correlation across most steering modes (Pearson r = 0.80-0.90). Short-wheelbase configurations (L = 400 mm) consistently achieve 25-35% lower turning energy than long-wheelbase equivalents (L = 800 mm). The globally optimal configuration - B600×L400 and B800×L400 in four-wheel point-turn mode - achieves a minimum turning energy of approximately 707-710 J, representing a 31% reduction relative to the worst-performing configuration. Among all tested platforms, B800×L400 (track width 800 mm, wheelbase 400 mm, B/L = 2.00) produced the most outstanding overall performance across both flat and sloped terrain, exhibiting superior agility, smooth and rapid manoeuvre execution, and excellent directional stability, including on the 18° incline. Skid-steering modes uniformly incur the highest energy penalties across all geometric configurations (3-25× relative to the optimal equivalent mode), and a predictive L²/B parameter is shown to capture skid-steer energy with high accuracy (r = 0.86-0.98). Four-wheel steering consistently outperforms two-wheel and skid-steering strategies, and the arc four-wheel steering mode exhibits near-constant energy (~1,016 J, CV = 14%) across all nine configurations, making it the most geometrically robust steering choice. On slope terrain, arc-path manoeuvres incur substantially higher energy (+38% to +98%) relative to flat-ground equivalents due to gravitational work along the arc path, while pivot-type skid-steering energy is reduced by up to 22% due to decreased wheel-ground normal force. A systematic rearward shift in axle load distribution is identified during arc manoeuvres on slope, with rear-axle drive motors carrying up to 2.7× the energy of front-axle motors - a mechanically significant finding for rear-axle motor sizing in slope-capable platforms. Bivariate regression models of the form E = f(B, L) are derived for all six steering modes, achieving R² = 0.70-0.98 and providing practical engineering formulae for early-stage energy estimation from geometric parameters. The platform, its instrumentation methodology, and the experimental dataset collectively constitute a validated experimental foundation for steering-related energy research in electric agricultural vehicles. The findings directly inform design guidelines for energy-efficient small-scale agricultural robots, with particular relevance to orchard and vineyard applications in which turning energy represents a critical fraction of total operational energy.
The care and cultivation of poisonous plants
(The University of Waikato, 2026-06-26) Berridge, Sandra; Chidgey, Catherine; Slaughter , Tracey
Set in London in 1932, The Care and Cultivation of Poisonous Plants is a historical crime novel centred on the murder of Cynthia Greenaway within the private residents' garden of St Mary's Square. While employing the framework of the traditional cosy mystery, the novel uses the enclosed community of the garden square to explore themes of female agency, trauma, identity, social control and belonging in the interwar period. The communal garden functions as both setting and organising metaphor. Interwoven throughout the narrative are extracts from the writings of the gardener, Brandon McSweeney, whose observations on cultivation, decay, adaptation and renewal provide a commentary on the lives of the residents and the unfolding investigation. Through this structure, the novel examines the interconnectedness of individual lives and the ways in which personal choices, social expectations and historical forces shape human behaviour. The narrative follows Gráinne Redman as she investigates a series of deaths linked to the square while confronting questions surrounding women's autonomy, reproductive rights and the gendered power structures of early twentieth-century Britain. The novel further engages with contemporary and historical debates surrounding eugenics, bodily autonomy and social conformity, exploring how individuals respond to trauma through resistance, accommodation or self-destruction. By combining conventions of Golden Age detective fiction with literary historical fiction, The Care and Cultivation of Poisonous Plants contributes to traditions of female-authored crime writing while reimagining the role of the woman detective as both investigator and advocate. The novel serves as the first in a projected series examining transgressive roles for women and the limitations imposed upon them within twentieth-century society.
Understanding the psychosocial impact of endometriosis-related persistent pain in Aotearoa New Zealand
(The University of Waikato, 2026) Mouton, Estie-Lomé; Curtis, Cate
Endometriosis-related persistent pain is often understood through biomedical frameworks focused on diagnosis, lesions, surgery, and symptom management. However, persistent pain also has emotional, cognitive, social, relational, and healthcare-mediated dimensions that shape how pain is lived and made meaningful over time. This qualitative study explored the psychosocial factors, dynamics, and processes that shape the lived experience of endometriosis-related persistent pain among women in Aotearoa New Zealand. In particular, it examined how emotional distress, meaning-making, interpersonal relationships, social recognition, support, and healthcare experiences influenced the ways in which pain was understood, managed, and lived with. The study was informed by a biopsychosocial understanding of persistent pain and sensitised by feminist health perspectives on gendered pain, legitimacy, and healthcare dismissal. Thirteen women with clinically diagnosed endometriosis and endometriosis-related persistent pain participated in in-depth semi-structured interviews. Data were analysed using reflexive thematic analysis. Five themes were developed: “No amount of pain should be normal”: struggling to legitimise pain; Waiting in pain: care pathways, uncertainty, and the cost of access; Living with an unpredictable and invisible body; Carrying pain internally: distress, self-doubt, and self-compassion; and Making pain liveable: support, relief, and whole-person care. Together, these themes showed an analytic movement from pain being questioned, to pain being prolonged, socially managed, internally carried, and made more liveable. Participants’ accounts showed that persistent pain was not only endured in the body, but also negotiated through healthcare systems, relationships, social expectations, internal meaning-making, and access to support. The findings suggest that endometriosis-related persistent pain cannot be understood through symptom severity, diagnosis, or treatment history alone. Instead, it is shaped by recognition, waiting, invisibility, distress, self-trust, and the forms of care and support that help restore agency, participation, and liveability.
Quaternary stratigraphy of the Tauranga basin
(The University of Waikato, 1983) Harmsworth, Garth; Nelson, Campbell S.; Briggs, Roger M.; Kamp, Peter J.J.
A 1:25000 scale geological map of the southern part of the Tauranga Basin is presented together with numerous stratigraphic columns to illustrate the late Cenozoic stratigraphic development and depositional patterns of the Basin. The Tauranga Basin lies 40 km north of the Taupo Volcanic Zone and immediately east of the Kaimai Range where Beesons Island Volcanics, aged 16 - 7 m.y. B.P., outcrop as an effective basement to the west and south of the Basin. The Basin originated by the northeast tilting of a large fault block, the western upturned edge now comprises the Kaimai Range and the Quaternary sequence infills the downtilted eastern margin. The tilting and hence age of the Basin mainly post-dates emplacement of the Waiteariki Ignimbrite, aged 0.84 m.y. B.P., which now immediately underlies both the Whakamarama Plateau of the southeastern Kaimai Range and the Quaternary succession in the Basin. At a few localities within the Basin Waiteariki Ignimbrite surrounds and laps onto Minden Rhyolite (4.34 m.y. B.P.) and Aongatete Ignimbrite (∼1.26 - 0.86 m.y. B.P.); these older rocks are sometimes overlain by Pleistocene deposits. The Matua Subgroup is formally erected to classify the Quaternary sequence within the Tauranga Basin. It comprises up to 240 m of terrestrial and estuarine sediments with interdigitating pyroclastic deposits both of an air-fall and flow origin (ignimbrites). The ignimbrites are classified and mapped as formations where they are subaerially exposed, and in stratigraphic order are: Wairoa Ignimbrite (∼0.6 m.y. B.P.), Te Puna Ignimbrite (∼0.4 m.y. B.P.), Te Ranga (∼0.3 m.y. B.P.) and the Waimakariri Ignimbrite (∼0.18 m.y. B.P.). The ignimbrites are unwelded and have suffered substantial post-depositional erosion thus providing the major source of the interstratified sediments of the Matua Subgroup. In many cases individual sedimentary units throughout the stratigraphic succession can be related by petrofacies studies to source ignimbrites. This enables the discrete tongues and lenses of sediments to be mapped as post-ignimbrite units. However these sedimentary units have not been formally defined as formations. A sequence of white to grey rhyolitic tephras up to 20 m thick and named the Pahoia tephras, are invariably part of the upper 40 m of the Subgroup and are intercalated with or overlie fluvial and pyroclastic flow deposits. Brown Hamilton Ash beds inturn overlie the Pahoia tephras and/or Matua Subgroup. The 42,000 yr B.P. Rotoehu Ash and younger Late Pleistocene-Holocene tephras mantle the present topography, and may overlie any of the stratigraphically older units. The pyroclastic flow deposits of the Matua Subgroup each show distinct but different textural and morphologic characteristics. These deposits are distinguished from air-fall units by their poorly sorted nature, coarser grain-sizes, and valley ponded distribution. The air-fall units are invariably thinner, shower bedded and mantle the paleo-topography. The fluvial sediments are dominated by planar stratification (Lenticular, Horizontal parallel, Horizontal discontinuous, Graded), and cross-stratification (Rho, Nu, and Alpha), and are interpreted as mainly braided river facies. The Taupo Volcanic Zone is considered the source of the Waiteariki Ignimbrite and younger pyroclastic flow deposits of the Matua Subgroup. A more northern, Coromandel Range, source is suggested for the older Aongatete Ignimbrite (∼1.26 - 0.86 m.y. B.P.). The Quaternary geological history of the region has been informally considered as three main periods: early Ignimbrite period (0.84 - 0.50 m.y. B.P.), a late Ignimbrite period (0.50 - 0.14 m.y. B.P.), and an upper Matua Subgroup period (∼0.16 m.y. B.P. - Present). The principal influences on the stratigraphic development and depositional patterns of the Basin are attributed to block faulting and tilting of the basement and adjacent Kaimai Range, volcanic activity in the Taupo Volcanic Zone, and to a lesser extent, climatic and glacio-eustatic sea-level changes.
Social surveys
(Taylor & Francis, 2020) Greenhalgh, Charlotte; Dobson, Miriam; Ziemann, Benjamin
From the late nineteenth century, social survey researchers used door-to-door interviews to advance knowledge of everyday life and to transform methods in their field. Historians read social survey archives for the data they contain; to analyse how and why researchers selected particular topics, categories, and populations; and to uncover the labour, technologies, and personal interactions that created these authoritative records of social life. The University of Melbourne Social Survey visited well over 7,000 households between 1941 and 1943. Its interviewers worked on a piecework basis as they spoke with Melburnians and co-produced social science data that were never published in full. The Melbourne archive showcases their intellectual contributions and underlines what historians gain when they analyse raw data and research notes.