초록 ▼

A system for avoiding singularities in a control moment gyro (CMG) array of a satellite uses closed and open loop control of the CMGs for reorientation of the satellite. A control system detects when closed loop control according to pseudo inverse rules will cause a singularity and issues a signal.

A system for avoiding singularities in a control moment gyro (CMG) array of a satellite uses closed and open loop control of the CMGs for reorientation of the satellite. A control system detects when closed loop control according to pseudo inverse rules will cause a singularity and issues a signal. The CMGs are then controlled open loop to avoid the singularity. The pseudo inverse singularity problem arises where there are more actuators than dimensions in the controlled space. Accordingly, the invention may also be used in a robotic arm manipulator.

대표청구항 ▼

[ What is claimed is:] [1.] A satellite attitude control comprising a plurality of control moment gyros, an attitude controller comprising signal processing means for providing a gimbal rate signal, for each control momentum gyro, to operate an actuator to rotate each control moment gyro to change t

[ What is claimed is:] [1.] A satellite attitude control comprising a plurality of control moment gyros, an attitude controller comprising signal processing means for providing a gimbal rate signal, for each control momentum gyro, to operate an actuator to rotate each control moment gyro to change the attitude of a vehicle from a first attitude to a second attitude in response to a commanded attitude signal and an inertial measurement unit for providing signals manifesting vehicle rotation, comprising:the signal processing means comprises:means for producing, for one of said control moment gyros, an error signal manifesting the difference between the commanded attitude and an actual attitude manifested by an attitude control signal, produced by the inertial measurement unit, and for producing from said error signal the gimbal rate signal according to a closed loop control and for producing a singularity signal manifesting that said closed loop produces a singularity for said error signal, for producing, in response to said singularity signal, said gimbal rate signal from an open loop control law sequence that causes said one control moment gyro to be rotated to apply its respective stored angular momentum in a direction that is approximated by a great circle between the first attitude and the second attitude on an imaginary sphere with a center at the center of rotation of the vehicle.