GyroWheel™ - An Innovative New Actuator/Sensor for 3-axis Spacecraft Attitude Control

The Bristol Gyro Wheel is an innovative attitude control system device that provides both an angular momentum bias and control torques about three axes while at the same time measuring the spacecraft angular rates about two axes. The principles of operation of this device are explained and the flight model design is described that is targeted at small satellite applications which is currently under development. A fully functional prototype of the GyroWheel has been developed that has demonstrated the actuator and rate sensing capabilities and some of the test results are given. One of the key advantages of the Gyro Wheel is that, for earth pointing applications, it can be used with a single 2- axis earth sensor to provide fine pointing control in all three axes. This allows for reducing the mass, power above all cost of this class of ACS system. A Gyro Wheel based ACS design is developed for an example case consisting of a small earth pointing microsat mission. Performance simulations are given that show that the pointing control can be maintained within 0.1 degrees in all axes. The Gyro Wheel promises to fulfill the need for low cost, low mass, high reliability and high accuracy attitude control systems for applications such as communications, remote sensing, and space science

Error Analysis and Error Allocation for Turntable Systems Used in GyroWheel Calibration Tests

Calibration tests are of great importance to ensure rate-sensing accuracy of GyroWheel, an innovative attitude determination and control device. In the process of calibration tests, turntable errors are inevitable, which hinder the calibration accuracy and rate-sensing capability. Hence, error analysis for GyroWheel calibration tests is conducted, and the relationship between the calibration accuracy and the orientation error is established based on analytical derivation and numerical simulations. Subsequently, an error model of the turntable system is derived using rigid body kinematics, by which the relationship between the orientation error and turntable errors is described. According to sensitivity analysis and manufacturing capability, an error allocation method is proposed to determine the accuracy requirement of the test turntable, and the effectiveness of the proposed method is verified by repeated simulation tests. Based on the presented analysis and proposed method in this paper, the effects of various turntable errors on the calibration accuracy can be obtained quantitatively, and a theoretical basis for the determination of the turntable accuracy is provided, which are of great significance to guide the calibration tests and improve the calibration accuracy of GyroWheel

The bicycle design concept

Diplomová práce obsahuje stručný úvod do problematiky navrhování cyklistických kol. Krátká čast práce je věnována samotné historii a členění kol do skupin a jejich zařazení podle předepsaných topologií. Dále v práci uvádím SWOT analýzu, kde srovnám současná řešení cyklistických kol a zhodnotím výsledky a praktičnost kol "uměleckých". Praktická část pojednává o návrhu a konstrukci cyklistického kola. Do samotného návrhu zahrnuji také návrh loga, které daný produkt ponese, a návrh dalších elementárních částí. Konečnou částí bude zakomponování inteligentních systémů pro zvýšení bezpečnosti cyklisty. Navrhování bude probíhat pomocí skic a modelovacích programů, jako jsou např. Catia V5 nebo 3Ds Max.The thesis contains a brief introduction to the design of a bicycle. The short part is dedicated to the history and structure of rounds into groups and their classification according to prescribed topologies. Furthermore, I mention SWOT analysis, where I compare the solutions of bicycles and evaluate the results and practicality of "art" bikes. The practical part deals with the actual design and construction of bicycle. By itself, the proposal also includes logo design, that this product shall bear a draft other elementary parts. The final part will be the incorporation of intelligent systems to enhance the safety of cyclists. Drafting will be done by sketching and modeling with programs such as Catia V5 or 3Ds Max

Volume 52 - Issue 3 - October, 1942

https://scholar.rose-hulman.edu/technic/1189/thumbnail.jp

You Can Ride Too! An Exploration of the Guided Discovery of Two-wheeled Cycling Skills by Youth with Intellectual Disabilities

Learning to ride a bike is an important milestone in the life of a child, yet many children with disabilities never have the opportunity to experience this success. Few studies have examined how to teach this skill to individuals with intellectual disabilities, with techniques that do not use specialized bicycles. The main purpose of this thesis was to explore the applicability of Cognitive Orientation to daily Occupational Performance (CO-OP) for teaching cycling to individuals with intellectual disabilities. Two studies were completed: a single case multiple baseline design across seven participants (ages 10-19), and an in-depth analysis of one of the cases. In the first study the seven youth—six with a diagnosis of Down syndrome, one with Smith-Lemli-Opitz syndrome—were videotaped over the course of the baseline, intervention and follow-up phases. Cycling skills and the maximum distance and time ridden were assessed and analyzed using the non-overlap of all pairs (NAP) method. Completion of the CO-OP intervention coincided with significant improvements in all measures for six of the seven participants. At follow-up, cycling distances for these 6 youth ranged from 31-1756m, time cycled extended from 11 seconds to over 9 minutes, and an average of over 10 of 20 independent cycling skills were gained. One participant did not learn how to ride and one did not participate in two-wheeled cycling after follow-up. In the second study involving the oldest participant with Down syndrome, the youth’s trajectory of learning and cycling skill acquisition was described along with the key features of CO-OP used to facilitate his learning. The results of these studies provide proof of principle that CO-OP may be an effective way to teach cycling to individuals with intellectual disabilities. Further evaluation is warranted to determine its potential use with others with intellectual disabilities or when teaching other skills

Saturn S-4B-505N stage flight evaluation report

Postflight analysis of prelaunch countdown, powered flight, and orbital phases of S-4B-505N stage of Apollo 10 launch vehicl

Angular Rate Sensing with GyroWheel Using Genetic Algorithm Optimized Neural Networks

GyroWheel is an integrated device that can provide three-axis control torques and two-axis angular rate sensing for small spacecrafts. Large tilt angle of its rotor and de-tuned spin rate lead to a complex and non-linear dynamics as well as difficulties in measuring angular rates. In this paper, the problem of angular rate sensing with the GyroWheel is investigated. Firstly, a simplified rate sensing equation is introduced, and the error characteristics of the method are analyzed. According to the analysis results, a rate sensing principle based on torque balance theory is developed, and a practical way to estimate the angular rates within the whole operating range of GyroWheel is provided by using explicit genetic algorithm optimized neural networks. The angular rates can be determined by the measurable values of the GyroWheel (including tilt angles, spin rate and torque coil currents), the weights and the biases of the neural networks. Finally, the simulation results are presented to illustrate the effectiveness of the proposed angular rate sensing method with GyroWheel

Dynamical Modelling and Vibration Analysis of the Non-coplanarity of the Orthogonal Support of Gyrowheel

Abstract In the engineering implementation of gyrowheel, the influence of orthogonal support non-coplanar is inevitable. However, when the gyrowheel is used for satellite inertial angular velocity measurement, this non-ideal factor will inevitably have an adverse impact on the accuracy of angular velocity measurement. Therefore, the dynamic model of gyrowheel with non-coplanar orthogonal support is established, and the influence of the non-coplanarity support on the vibration frequency is analysed. Finally, the correctness of this research is verified by simulation.</jats:p