scholarly journals Calibration, Compensation and Accuracy Analysis of Circular Grating Used in Single Gimbal Control Moment Gyroscope

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1458 ◽  
Author(s):  
Yue Yu ◽  
Lu Dai ◽  
Mao-Sheng Chen ◽  
Ling-Bo Kong ◽  
Chao-Qun Wang ◽  
...  
Keyword(s):  
Low Cost ◽  
Angular Position ◽  
Compensation Method ◽  
Position Measurement ◽  
Control Moment Gyroscope ◽  
Control Precision ◽  
Control Moment ◽  
Single Reading ◽  
Calibration Experiment ◽  
Circular Grating

The accuracy of the circular grating is the key point for control precision of the single gimbal control moment gyroscope servo system used in civilian micro-agile satellites. Instead of using the multi reading heads to eliminate eccentricity errors, an algorithm compensation method based on a calibration experiment using a single reading head was proposed to realize a low-cost and high accuracy angular position measurement. Moreover, the traditional hardware compensation method using double reading heads was also developed for comparison. Firstly, the single gimbal control moment gyroscope system of satellites was introduced. Then, the errors caused by the installation of the reading head were studied and the mathematic models of these errors were developed. In order to construct the compensation function, a calibration experiment using the autocollimator and 24-sided prism was performed. Comparison of angle error compensation using the algorithm and hardware method was presented, and results showed that the algorithm compensation method proposed by this paper achieved the same accuracy level as the hardware method. Finally, the proposed method was further verified through a control system simulation.

scholarly journals Design and Structural Analysis of a Control Moment Gyroscope (CMG) Actuator for CubeSats

Aerospace ◽  
2020 ◽  
Vol 7 (5) ◽  
pp. 55
Author(s):  
Alexis Gaude ◽  
Vaios Lappas
Keyword(s):  
Structural Analysis ◽  
Low Cost ◽  
Mechanical Assembly ◽  
Physical Size ◽  
Control Moment Gyroscope ◽  
Control Moment ◽  
Global Trend ◽  
Electronic Board ◽  
Stepper Motors ◽  
Low Mass

Following a global trend towards miniaturization, the population of nano- and micro-satellite continues to increase. CubeSats are standardized small size satellites based on 10 × 10 × 10 cm cube modules (1U) and are becoming sophisticated platforms despite their very small size. This paper details the design and the structural analysis of a Control Moment Gyroscope (CMG) actuator for agile CubeSats with a physical size up to 12U, which require high torque actuators. CMGs have inherited torque amplification capabilities and the recent advances in motor miniaturization make them ideal candidates for small satellite missions with slew rate requirements. The system’s requirements are derived based on conceptual agility requirements for an agile (highly maneuverable) CubeSat which needs to achieve a 90° maneuver in 90 s. With specific cost, mass and volume requirements, the proposed CMG design is based on some of the smallest available off-the-shelf electric motors and uses a light aluminum casing design. The proposed design uses stepper motors for the gimbal mechanism as a low cost, compact and low power solution, contributing to an overall low mass of the full CMG cluster. Static and dynamic analyses were performed to assess the mechanical integrity of the system for launch loads. Apart from a necessary custom control electronic board, the complete mechanical assembly has been designed including electrical hardware. Analyses demonstrate that the overall stress levels acting on the system are manageable by the CMG design. Bolted joints are critical and should be studied independently as the chosen model created singularities around these areas. Each individual CMG of the designed pyramidal cluster is shown to weigh about 35 g. Using the proposed CMG design with a customized avionics board, the complete CMG system is shown to weigh 250 g and occupies slightly more than ½U volume for a CubeSat, indicating the feasibility of CMGs for agile CubeSats.

Oscillating Control Moment Gyroscope Experimental Results

2019 ◽  
Author(s):  
Burak Akbulut ◽  
Ozan Tekinalp ◽  
Ferhat Arberkli ◽  
Kivanc Azgin
Keyword(s):  
Experimental Results ◽  
Control Moment Gyroscope ◽  
Control Moment

scholarly journals Assessment of the Accuracy of Determining the Angular Position of the Unmanned Bathymetric Surveying Vehicle Based on the Sea Horizon Image

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4644 ◽  
Author(s):  
Naus ◽  
Marchel ◽  
Szymak ◽  
Nowak
Keyword(s):  
Angular Position ◽  
Complementary Metal Oxide Semiconductor ◽  
General Concept ◽  
Oxide Semiconductor ◽  
Position Measurement ◽  
The Matrix ◽  
Horizon Line ◽  
Aerial Vehicle ◽  
Line Slope ◽  
Further Development

The paper presents the results of research on assessing the accuracy of angular position measurement relative to the sea horizon using a camera mounted on an unmanned bathymetric surveying vehicle of the Unmanned Surface Vehicle (USV) or Unmanned Aerial Vehicle (UAV) type. The first part of the article presents the essence of the problem. The rules of taking the angular position of the vehicle into account in bathymetric surveys and the general concept of the two-camera tilt compensator were described. The second part presents a mathematical description of the meters characterizing a resolution and a mean error of measurements, made on the base of the horizon line image, recorded with an optical system with a Complementary Metal-Oxide Semiconductor (CMOS) matrix. The phenomenon of the horizon line curvature in the image projected onto the matrix that appears with the increase of the camera height has been characterized. The third part contains an example of a detailed analysis of selected cameras mounted on UAVs manufactured by DJI, carried out using the proposed meters. The obtained results including measurement resolutions of a single-pixel and mean errors of the horizon line slope measurement were presented in the form of many tables and charts with extensive comments. The final part presents the general conclusions from the performed research and a proposal of directions for their further development.

Towards Automated Bicycles: Achieving Self-Balance Using Steering Control

2018 ◽  
Author(s):  
Wenhao Deng ◽  
Skyler Moore ◽  
Jonathan Bush ◽  
Miles Mabey ◽  
Wenlong Zhang
Keyword(s):  
Autonomous Vehicles ◽  
Controller Design ◽  
Smart Cities ◽  
Autonomous Driving ◽  
Human Robot Interaction ◽  
Steering Control ◽  
Control Moment Gyroscope ◽  
Control Moment ◽  
Potential Applications ◽  
Electric Bicycle

In recent years, researchers from both academia and industry have worked on connected and automated vehicles and they have made great progress toward bringing them into reality. Compared to automated cars, bicycles are more affordable to daily commuters, as well as more environmentally friendly. When comparing the risk posed by autonomous vehicles to pedestrians and motorists, automated bicycles are much safer than autonomous cars, which also allows potential applications in smart cities, rehabilitation, and exercise. The biggest challenge in automating bicycles is the inherent problem of staying balanced. This paper presents a modified electric bicycle to allow real-time monitoring of the roll angles and motor-assisted steering. Stable and robust steering controllers for bicycle are designed and implemented to achieve self-balance at different forward speeds. Tests at different speeds have been conducted to verify the effectiveness of hardware development and controller design. The preliminary design using a control moment gyroscope (CMG) to achieve self-balancing at lower speeds are also presented in this work. This work can serve as a solid foundation for future study of human-robot interaction and autonomous driving.

scholarly journals MR Damper-Based Vibration Suppression Method for Control Moment Gyroscope

2018 ◽  
Vol 36 (5) ◽  
pp. 884-889
Author(s):  
Wendong Wang ◽  
Xing Ming ◽  
Yang Chu ◽  
Minghui Liu ◽  
Yikai Shi
Keyword(s):  
Active Control ◽  
Control Algorithm ◽  
Vibration Suppression ◽  
Control Method ◽  
Magnetorheological Damper ◽  
Magnetic Flux Density ◽  
Damping Force ◽  
Control Moment Gyroscope ◽  
Control Moment ◽  
Suppression Method

To restrain the interference of micro-vibration caused by Control Moment Gyroscope, a new control method based on Magnetorheological damper was proposed in this paper. A mechanical model based on the structure of the presented design was built, and the semi-active control algorithm of damping force was proposed for the designed Magnetorheological damper. The magnetic flux density and other magnetic field parameters were considered and analyzed in Maxwell, and also the related hardware circuit which implements the control algorithm was prepared to test the presented design and algorithm. The results of simulation and experiments show that the presented Magnetorheological damper model and semi-active control algorithm can complete the requirements, and the vibration suppression method is efficient for Control Moment Gyroscope.

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