Low latency vision-based control for robotics : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Mechatronics at Massey University, Manawatu, New Zealand

In this work, the problem of controlling a high-speed dynamic tracking and interception system using computer vision as the measurement unit was explored. High-speed control systems alone present many challenges, and these challenges are compounded when combined with the high volume of data processing required by computer vision systems. A semi-automated foosball table was chosen as the test-bed system because it combines all the challenges associated with a vision-based control system into a single platform. While computer vision is extremely useful and can solve many problems, it can also introduce many problems such as latency, the need for lens and spatial calibration, potentially high power consumption, and high cost. The objective of this work is to explore how to implement computer vision as the measurement unit in a high-speed controller, while minimising latencies caused by the vision itself, communication interfaces, data processing/strategy, instruction execution, and actuator control. Another objective was to implement the solution in one low-latency, low power, low cost embedded system. A field programmable gate array (FPGA) system on chip (SoC), which combines programmable digital logic with a dual core ARM processor (HPS) on the same chip, was hypothesised to be capable of running the described vision-based control system. The FPGA was used to perform streamed image pre-processing, concurrent stepper motor control and provide communication channels for user input, while the HPS performed the lens distortion mapping, intercept calculation and “strategy” control tasks, as well as controlling overall function of the system. Individual vision systems were compared for latency performance. Interception performance of the semi-automated foosball table was then tested for straight, moderate-speed shots with limited view time, and latency was artificially added to the system and the interception results for the same, centre-field shot tested with a variety of different added latencies. The FPGA based system performed the best in both steady-state latency, and novel event detection latency tests. The developed stepper motor control modules performed well in terms of speed, smoothness, resource consumption, and versatility. They are capable of constant velocity, constant acceleration and variable acceleration profiles, as well as being completely parameterisable. The interception modules on the foosball table achieved a 100% interception rate, with a confidence interval of 95%, and reliability of 98.4%. As artificial latency was added to the system, the performance dropped in terms of overall number of successful intercepts. The decrease in performance was roughly linear with a 60% in reduction in performance caused by 100 ms of added latency. Performance dropped to 0% successful intercepts when 166 ms of latency was added. The implications of this work are that FPGA SoC technology may, in future, enable computer vision to be used as a general purpose, high-speed measurement system for a wide variety of control problems

African women as effective managers in the Free State Provincial Government: addressing performance determinants

ThesisChange is a process which, although feared and resisted by many, is unfortunately often inevitable. South Africa, with all its diversity, was no exception, and had to experience its fair share of change with the quantum leap from an Apartheid regime to a democratic government where equality reigns supreme. Democracy in South Africa has brought many benefits, particularly for previously disadvantaged citizens such as African women, who until 1994 had never experienced westernised democracy as professional women in South Africa. Several mechanisms in the South African areas of government and academia have paved the way for African women to enter the labour force as managers in the past decade. Legislation was one area in which gender equality was aggressively promoted. However, it soon became apparent that legislation per se would not be enough to ensure the level of equality that these professional women had hoped for. Several factors influenced the lives and performance of African women managers. This study focused on cultural history, demographic variables and certain operational factors as areas which have had an influence on African women managers in respect of their ability to perform effectively and to deliver effective services. Although it is true that cherished cultures and traditions can enrich a country, some traditions have a detrimental effect on advancement of any kind and should rather be changed so as to benefit all individuals belonging to a certain culture. Examples of such traditions include the customary law, in terms of which an African woman immediately reverted to the status of a minor after marriage, and the "ubuntu" prinCiple, which fosters collective group identity and emotional dependence. These two traditions have undeniably influenced the effective functioning of African women managers negatively. This study has touched on the effect of several of these customary practices, as well as the impact of legislation that was passed after the 1994 elections. Through this investigation, it became evident that a major breakthrough has nevertheless been made regarding the rights and status of professional African women. A survey questionnaire targeting the 79 African women managers in the Free State Provincial Administration was conducted. This was followed by a focus group discussion amongst eight participant from the original sample, as a supporting method of data collection. On a demographic level, significant information was derived from the research. It became apparent that African women managers in the Free State Provincial Administration functioned independently in the social, economic and professional spheres of their lives. The respondents were all well educated, finanCially independent, career-orientated and valued having children of their own. They preferred a lifestyle that would fulfil their needs, while also contributing to the enhancement of their skills and effectiveness as professional women. In the work environment, African women managers experienced factors that influenced their managerial effectiveness both negatively and positively. It was apparent that not all of them were involved in crucial managerial actions that would normally be expected of them; and also that they were sometimes still deliberately denied exposure as managers. This resulted in a lack of basic managerial skills, such as change management, on the part of African women managers. On the positive side, they all had confidence in their judgement and competence to function effectively; but indicated that they wished to enhance their managerial skills. Following the findings of the survey and focus group an appraisal model was firstly introduced, in order to measure the performance of African women managers in the Free State Provincial Administration by means of a competency checklist. This model makes it possible for the African woman manager to evaluate her own performance and also enables the institution, in turn, to measure her managerial effectiveness in terms of the key performance areas stipulated in the checklist. Secondly, the research proposes a quality assurance model to i) provide standards of service excellence for the measurement and subsequent improvement of the actual level of managerial competence within the institution; and ii) create an integrated human resource skills development framework for managers. Both these models aim to create mechanisms to enhance the managerial effectiveness of the African woman manager and the quality of service delivery of the institution as continuously demanded by a democratic dispensation

Service delivery and ethical conduct in the public service: the missing links

There are a multitude of policies, strategies and programmes directed at the rendering of effective services to the citizens of South Africa by public service managers. However, in spite of the pursuit of effectiveness and the condemning of unethical behaviour by public service managers, scandals still occur and allegations are still made. So, where are the missing links? In this article, a brief description is given of some ethical concepts viewed as important in addressing the question posed. The concluding remarks are twofold: public service organisations need to provide continuous commitment, enforcement, and modelling of leadership in professional ethics by means of, among other things, policy structures; and public service managers need to realise the importance of changing their own mindset and accepting the ethical standards that are established by the public service organisation, even if these differ from their own beliefs and culture

The history of professional African women : a South African perspective

Published ArticleThis article reviews the perspectives on the rights, roles and endeavours of women in the South African work environment. In an attempt to achieve this objective, the article commences with a holistic approach on the evolution of women's rights and roles. The remainder gives perspectives on the South African labour force and finally outlines the importance of South African legislation on the advancement of women. The situation of African women is, in particular referred to, as it was evident during 1995 and earlier that African females were considerably under-represented in various sectors of the workforce. African women were, for example, introduced into the management environment as recently as the 1980s, while supportive legislation only came into place in the 1990s

Assessing the implementation of employment equity in a Category C district municipality

Published ArticleThe South African Public Sector is based on democratic values and principles enshrined in the Constitution. One of those crucial principles is the promotion of efficiency and the economic and effective utilisation of resources. By implication, the achievement of this principle is only possible if people with the correct skills, qualifications and knowledge are selected to lead government projects and programmes. However, the country's unrepresentative labour force, as well as their disadvantage with regard to skills, poses a challenge within the Public Sector. The purpose of this paper is to assess the implementation of employment equity in a category C District Municipality. Focus-group discussions targeting the respective District Municipalities were conducted. The interview schedule demarcated three sections. The first focused on the respondents' awareness of legislative directives, the second on the implementation of a 2005 Employment Equity Plan, and the third on the importance of relevant legislation that was passed by the Government to address imbalances in employment equity. Results indicate that even though some progress was evident, the implementation of the 2005 Employment Equity Plan was slow and consequently the District Municipality under investigation was unable to reach its set targets. Although several reasons are given for this state of affairs, the biggest concern is the absence of the commitment of the Municipal Council in implementing the Plan

Short communication Dairy farm borehole water quality in the greater Mangaung region of the Free State Province, South Africa

Published ArticleMost dairy farm effluent is discharged onto pastures and land by irrigation and poses a risk of enriching groundwater including borehole drinking water. Nitrate, coliforms and Escherichia coli (E. coli), in particular, may cause disease in humans and animals drinking contaminated water. The aim of this study was to obtain an understanding of the status of borehole drinking water quality, including physical, chemical and microbiological properties, on 75 dairy farms in the greater Mangaung region of the Free State, South Africa. Borehole drinking water samples were collected during autumn and spring of 2009 and the physical, chemical and microbiological parameters analysed and compared to the required standards prescribed by the South Africa National Standards (SANS) 241 of 2006. Most farms were compliant; however for combined nitrate and nitrite N, 37 of the farms exceeded the prescribed limit. Similarly, for total coliforms, 45 and for E. coli, 22 of the farms exceeded the acceptable limits. Nine of the farm boreholes were contaminated by N and E. coli. On one farm all of the bacteriological parameters and four of the chemical parameters exceeded the prescribed limits, and on two other farms four and five of the chemical parameters were exceeded. Further studies on water and waste management on dairy farms in the Manguang region of the Free State are suggested

The contribution of fatty acids to the composition of the total lipids in juvenile Cape hake fillets - research

Published ArticleDue to the decline in fish stocks more juvenile fish are being caught. The aim of this study was to investigate the contribution of short and medium chain length fatty acids to the composition of the total lipids in juvenile Cape hake fillets and the impact thereof the nutritional value. The fatty acids that most contributed to the total fatty acid composition were palmitic acid (C16:0) (46.52%), docosahexaenoic acid (C22:6) (25.68%) and stearic acid (C18:0) (9.4%). Saturated fatty acid contribution to the total lipid content was found to be higher than reported in literature in other hake species and no eicosapentaenoic acid was detected. Eicosanoic acid, was detected only in the medium sized hake fillets, indicating reduced nutritional value in juvenile hake fillets. The challenges of the fishing industry is thus not only to control the sustainability of fish resources, but also the size of the total allowable catch to ensure the best nutritional level

Advancing democracy via responsive tertiary public administration offerings

Some foremost authors have suggested that democracy is not what we have but what we do, and that democracy and sustainability are two intangible drivers of economic growth and prosperity. Although the literature points to the importance of citizen participation in the governance of a democracy, it is evident that participation does not always prove to be effective and that members of society are not always aware of what is expected of them in order to sustain and strengthen a democracy. This article reports on a survey targeting students enrolled for modules in Public Administration at a South African university, to establish what the current generation (Generation Y) is doing to contribute to and strengthen the South African democracy. The findings show that the issues of participation, education, job creation and equality were considered important by the respondents

Microbial counts of food contact surfaces at schools depending on a feeding scheme

Published ArticleThe prominence of disease transmission between individuals in confined environments is a concern, particularly in the educational environment. With respect to school feeding schemes, food contact surfaces have been shown to be potential vehicles of foodborne pathogens. The aim of this study was to assess the cleanliness of the surfaces that come into contact with food that is provided to children through the National School Nutrition Programme in central South Africa. In each school under study, microbiological samples were collected from the preparation surface and the dominant hand and apron of the food handler. The samples were analysed for total viable counts, coliforms, Escherichia coli, Staphylococcus aureus and yeasts and moulds. The criteria specified in the British Columbia Guide for Environmental Health Officers were used to evaluate the results. Total viable counts were high for all surfaces, with the majority of colonies being too numerous to count (over 100 colonies per plate). Counts of organisms were relatively low, with 20% of the surfaces producing unsatisfactory enumeration of S. aureus and E. coli and 30% unsatisfactory for coliforms. Yeast and mould produced 50% and 60% unsatisfactory counts from preparation surfaces and aprons, respectively. Statistically significant differences could not be established amongst microbial counts of the surfaces, which suggests cross-contamination may have occurred. Contamination may be attributed to foodstuffs and animals in the vicinity of the preparation area rather than to the food handlers, because hands had the lowest counts of enumerated organisms amongst the analysed surfaces