Brachiating power line inspection robot: controller design and implementation

The prevalence of electrical transmission networks has led to an increase in productivity and prosperity. In 2014, estimates showed that the global electric power transmission network consisted of 5.5 million circuit kilometres (Ckm) of high-voltage transmission lines with a combined capacity of 17 million mega-volt ampere. The vastness of the global transmission grid presents a significant problem for infrastructure maintenance. The high maintenance costs, coupled with challenging terrain, provide an opportunity for autonomous inspection robots. The Brachiating Power Line Inspection Robot (BPLIR) with wheels [73] is a transmission line inspection robot. The BPLIR is the focus of this research and this dissertation tackles the problem of state estimation, adaptive trajectory generation and robust control for the BPLIR. A kinematics-based Kalman Filter state estimator was designed and implemented to determine the full system state. Instrumentation used for measurement consisted of 2 Inertial Measurement Units (IMUs). The advantages of utilising IMUs is that they are less susceptible to drift, have no moving parts and are not prone to misalignment errors. The use of IMU's in the design meant that absolute angles (link angles measured with respect to earth) could be estimated, enabling the BPLIR to navigate inclined slopes. Quantitative Feedback Control theory was employed to address the issue of parameter uncertainty during operation. The operating environment of the BPLIR requires it to be robust to environmental factors such as wind disturbance and uncertainty in joint friction over time. The resulting robust control system was able to compensate for uncertain system parameters and reject disturbances in simulation. An online trajectory generator (OTG), inspired by Raibert-style reverse-time symmetry[10], fed into the control system to drive the end effector to the power line by employing brachiation. The OTG produced two trajectories; one of which was reverse time symmetrical and; another which minimised the perpendicular distance between the end gripper and the power line. Linear interpolation between the two trajectories ensured a smooth bump-less trajectory for the BPLIR to follow

Role of security guards in healthcare settings: a protocol for a systematic review

Introduction There is a paucity of literature on the comprehensive roles of security guards in healthcare, regardless of day-to-day observations of security guards playing an extensive role in this field. Thus, this review will systematically explore the roles of security guards in healthcare contexts to create a centred body of evidence.Methods and analysis The study will systematically review existing quantitative and qualitative peer-reviewed literature on security guards in institutional healthcare so as to understand their roles. We will conduct the systematic review on 10 electronic databases: BioMed Central, SocIndex, ScienceDirect, Google Scholar, JSTOR, PsycARTICLES, PsycINFO, Scopus, Web of Science and PubMed. Data extraction will be in the form of a word document. Mendeley software will be used to keep track of references, while the systematic review software, Rayyan, will be used for the screening, inclusion and exclusion of articles. If necessary, reviewer number 3 will conduct a third review should any disputes arise between the two initial reviewers. Quality assessment of the articles will be measured with the Critical Appraisal Skills Programme tool for articles in terms of the research aims, methodology used, sample, data analysis, presentation of findings, values of the research, as well as trustworthiness if it is a qualitative study or reflexiveness if it is a quantitative study. Studies dating back 32 years will be incorporated for a comprehensive review.Ethics and dissemination This systematic review will use publicly available peer-reviewed data from electronic databases and will, therefore, not require an ethical review, but rather, an ethics waiver. The systematic review protocol will be submitted for ethics waiver clearance from the Stellenbosch University Health Research Ethics Committee. The findings from this review will be disseminated through peer-reviewed publications and conferences.PROSPERO registration number CRD42022353653