초록 ▼

An attitude control system for a spacecraft includes sensors for generating attitude control signals and logic for producing torque demand signals in the form of a Td matrix. The thrusters are oriented in complementary pairs about the center of mass for, when energized, producing mutually opposite t

An attitude control system for a spacecraft includes sensors for generating attitude control signals and logic for producing torque demand signals in the form of a Td matrix. The thrusters are oriented in complementary pairs about the center of mass for, when energized, producing mutually opposite torques. Information about the location of thrusters and their thrusts may be represented by a pulse-width-to-torque transformation matrix C. A weighted pseudo inverse of C is precalculated as Q=WC′(CWC′)-(13) and is stored in memory associated with the flight computer, thereby avoiding the need for the flight computer to perform the intensive calculations of Q. Thruster pulsewidth for attitude control is easily calculated by the flight computer as Dp=tpQTd (14) where tp is the control cycle time.

대표청구항 ▼

A satellite thruster control system, comprising: attitude sensing means for generating attitude signals representative of the 3-axis attitude of said spacecraft; a plurality of thrusters associated with said spacecraft, said thrusters being arranged in pairs which produce mutually opposed torques; m

A satellite thruster control system, comprising: attitude sensing means for generating attitude signals representative of the 3-axis attitude of said spacecraft; a plurality of thrusters associated with said spacecraft, said thrusters being arranged in pairs which produce mutually opposed torques; memory means located on said spacecraft, said memory means being loaded with a transformation matrix, which transformation matrix is the weighted pseudo inverse of the torque matrix, said torque matrix represents the maximum torque achievable by each of said thruster pairs, and its direction relative to said 3 axes; error signal generating means located on said spacecraft, and coupled to said attitude sensing means, for receiving said attitude signals, and for comparing said 3-axis attitude with a target attitude to generate error signals representative of the deviation of said 3-axis attitude from said target attitude; attitude control means located on said spacecraft, and coupled to said error signal generating means, for converting said error signals into torque demand signals in the form of a vector representative of the 3-axis torques required for moving said 3-axis attitude toward said target attitude; thruster control means located on said spacecraft, and coupled and to said attitude control means for multiplying said torque demand signals by said transformation matrix for generating a matrix of pulse width signals, the magnitudes of each of said pulse width signals of said matrix being proportional to the pulse width to be applied to one thruster of a pair of said thrusters producing mutually opposed thrust relative to said 3 axes, and the sign of each of said pulse width signals being representative to that one of said thrusters of each said pair which is to be energized in response to one of said pulse width signals; and pulse distribution logic means located on said spacecraft, and coupled to said thrusters and to said thruster control means for distributing each of said pulse width signals to one thruster of a corresponding one of said pairs of thrusters in accordance with said sign.