DETERMINING HEAD POSITION TO ASSIST ELECTRIC-POWERED WHEELCHAIR OPERATION FOR PERSONS WITH TRAUMATIC BRAIN INJURY

Monitoring head position in persons with a traumatic brain injury may provide a means for independent powered mobility. Given the often limited residual functions of attending, visual processing, and motor control, the operation of an electric-powered wheelchair must be constantly monitored to ensure the safety of these users. Human-directed support is not always available and does not encourage independent mobility. The solution proposed for this problem is placement of a magnet on the rear of the person's head. Strategically placed linear analog Hall effect sensors that are fixed in a stationary headrest can then track the magnet; thus, accurately determining head positioning. With this proposed head tracking, a specialized interface to the electric-powered wheelchair controller can be used to ensure the person's head is attending the direction of travel asserted by a conventional, direction-sensing joystick

Navigation Errors Introduced By Ground Vehicle Dynamics

An analysis of navigational accuracy when influenced by ground vehicle dynamics is presented. Tests beds outfitted with various sensor suites were used to collect data when normal and extreme driving maneuvers are executed. The data was run through an extended Kalman filter to produce a navigation solution. The Kalman filter inputs varied on each test bed, using both automotive and tactical grade Inertial Measurement Units (IMU). The position, velocity, and course measurements were obtained from a DGPS unit mounted on the vehicles and used as a truth measurement when exploring dead reckoning error. Additional measurements, such as wheel speed, radar speed, and magnetometer heading, were added to improve the robustness and reliability of the solution. The results of the work show the effect of both longitudinal and lateral vehicle slip on the navigation solution. In addition, the attempt of the various sensors to correct the errors is investigated. Reprinted with permission from The Institute of Navigation (http://ion.org/) and The Proceedings of the 18th International Technical Meeting of the Satellite Division of The Institute of Navigation, (pp. 302-316). Fairfax, VA: The Institute of Navigation

The Relationship Between Counseling Students’ Theoretical Orientation and Treatment Outcomes

A MANCOVA was conducted to determine differences in client treatment outcomes based on counseling students’ theoretical orientations. Results indicated that at a training clinic, clients demonstrated statistically significant improvement and, students’ theoretical orientation did not significantly affect client outcomes. Pedagogical strategies are suggested for counselor educators and supervisors

On the vehicle sideslip angle estimation: a literature review of methods, models and innovations

Typical active safety systems controlling the dynamics of passenger cars rely on real-time monitoring of the vehicle sideslip angle (VSA), together with other signals like wheel angular velocities, steering angle, lateral acceleration, and the rate of rotation about the vertical axis, known as the yaw rate. The VSA (aka attitude or “drifting” angle) is defined as the angle between the vehicle longitudinal axis and the direction of travel, taking the centre of gravity as a reference. It is basically a measure of the misalignment between vehicle orientation and trajectory therefore it is a vital piece of information enabling directional stability assessment, in transients following emergency manoeuvres for instance. As explained in the introduction the VSA is not measured directly for impracticality and it is estimated on the basis of available measurements like wheel velocities, linear and angular accelerations etc. This work is intended to provide a comprehensive literature review on the VSA estimation problem. Two main estimation methods have been categorised, i.e. Observer-based and Neural Network-based, focusing on the most effective and innovative approaches. As the first method normally relies on a vehicle model, a review of the vehicle models has been included. Advantages and limitations of each technique have been highlighted and discussed

Action module planning and Cartesian based control of an experimental climbing robot

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997.Includes bibliographical references (leaves 88-95).by David M. Bevly.M.S

LONGITUDINAL TIRE FORCE ESTIMATION WITH UNKNOWN INPUT OBSERVER

ABSTRACT This paper presents the development of a longitudinal tire force estimation algorithm. Rather than using highly nonlinear tire-road friction models, we propose a decentralized estimation algorithm which treats the longitudinal tire force of the individual wheel as an unknown input signal for the one-DOF wheel dynamic model. Two types of unknown input observers are designed to estimate the longitudinal tire force based on the wheel speed measurement in this study. To make the estimated tire force signals also satisfy the longitudinal dynamic model of the vehicle, the estimation results of the unknown input observer are integrated with the longitudinal acceleration measurement by using a projection method

Effect of modified atmosphere packaging on the quality and bioactive compounds of Chinese cabbage (Brasicca rapa L. ssp. chinensis)

BACKGROUND : The perishability of Brassica chinensis poses a major challenge to distribution and marketing. The aim of this work was to select a suitable modified atmosphere packaging to retain the overall quality and bioactive compounds during storage. RESULTS : Four types of biorientated polypropylene packaging (BOPP) – BOPP03, BOPP04, BOPP05 and BOPP06 – with different perforations were evaluated regarding the maintenance of quality parameters (weight loss, leaf yellowing, colour L*, C*, h°), decay, chlorophyll a, chlorophyll b, bioactive compounds (carotenoids, ascorbic acid, total phenolic compounds), antioxidant scavenging activity, overall appearance and odour evaluation, at 10°C at 2, 4, 6, 8 and 10 days. Leaves were packed in BOPP (two 2-mm holes) and packed and unpacked leaves were included for comparison. The modified atmosphere created (2% O2 and 7% CO2) inside the BOPP05 reduced leaf yellowing (higher h°), improved the overall appearance with acceptable odour, moderately maintained chlorophyll a and b, bioactive compounds and antioxidant scavenging activity, and remained marketable for up to 10 days at 10°C. Gas composition within the packages influenced the retention of bioactive compounds and overall quality. CONCLUSION : Application of BOPP05 is a promising method for extending the shelf life of B. chinensis leaves in order to promote its utilisation and commercialisation via urban fresh-produce markets.The National Research Foundation (NRF), South Africa as well as the postgraduate bursary award from the Tshwane University of Technology Research & Innovation Directorate, Pretoria, South Africa, to Ms Bevly Mmakatane Mampholo.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-0010hb2016Biochemistr