Design and manufacturing of a research magnetic torquer rod

Abstract

Microsatellites are the lowest price spacecrafts for lunch to their orbit. As a result, recently they are extensively employed in space missions. In these satellites it has been tried to use less heavy and simple hardware with higher reliability and energy efficiency. Magnetorquers are mainly used in Satellite Attitude Control Systems (ASC) as a control actuator. These actuators generate desired controllable torques. The Magnetorquers have the characteristics of a relatively lightweight and they also require no moving parts, expendables, and complex hardware. These minimum requirements have motivated scientific community to employ actuators in spacecrafts extensively. This paper presents Design procedures and manufacturing of a research magnetorquer in Aerospace Research Laboratory of K.N.Toosi University of Technology, Iran. Firstly, a mathematical model for design of a magnetorquer is explained, and the significant parameters for manufacturing of an efficient actuator are extended. Then Strategic Planning for design of a magnetorquer is expanded. At the end driver and demagnetization circuits are presented and the research magnetorquer with its participant circuits are discussed.

Demagnetizing correction in permeability measurements of cylinders

“…When χ is large, the above feature of equation ( 6) becomes less important, and the accurate determination of χ requires sufficiently large γ , as in the situation of equation ( 2) for the magnetometric case. Although ring samples with circular magnetization (so without demagnetizing effects) are standard for the case of high χ , direct measurements of midplane and volume-averaged μ ext on a long cylinder to study χ and its uniformity are especially important for certain magnetic devices, such as the magnetic core of a self-inductance or a magnetic torquer rod for spacecraft attitude control [13]. In such devices, large values of material χ are required throughout the entire core or rod and are realized by optimizing material composition and heat treatment.…”

Advanced fault detection and diagnosis in spacecraft attitude control systems: Current state and challenges

“…The ACS provides the required pointing accuracy and stability of payloads and antennas that need to be directed in a precise and/or specific orientation. Typically, a three-axis stabilized ACS consists of three main parts that include the following:(1) A set of actuators (spinning mechanisms) such as reaction wheels, 29,30 momentum wheels, magnetic torque rods, 31 or thrusters;(2) A set of sensors (optical part) such as Sun sensors, star trackers, Earth sensors, or magnetometers; 28 (3) Software for control law calculations and determination of spacecraft attitude information that can be interpreted by sensor measurements. 32,33 …”

“…(1) A set of actuators (spinning mechanisms) such as reaction wheels, 29,30 momentum wheels, magnetic torque rods, 31 or thrusters;…”

“…(1) A set of actuators (spinning mechanisms) such as reaction wheels, 29,30 momentum wheels, magnetic torque rods, 31 or thrusters; (2) A set of sensors (optical part) such as Sun sensors, star trackers, Earth sensors, or magnetometers; 28 (3) Software for control law calculations and determination of spacecraft attitude information that can be interpreted by sensor measurements. 32,33 Many strategies for ACSs have been proposed, but the FDD aspect of these systems remains a crucial and open subject.…”