Torque generation system, attitude control system for spacecraft, and relative position and velocity control system for spacecraft

Abstract

A torque generation system includes: a plurality of solar array panels and/or solar array panel divisions; and a torque controller configured to control an electricity generation ratio of each of the plurality of solar array panels and/or solar array panel divisions to generate torque.

What is claimed is: 
     
         1 . A torque generation system, comprising:
 a plurality of solar array panels and/or solar array panel divisions; and   a torque controller configured to control an electricity generation ratio of each of the plurality of solar array panels and/or solar array panel divisions to generate torque.   
     
     
         2 . The torque generation system according to  claim 1 , wherein
 the electricity generation ratio is controlled by turning on, turning off, or switching a shunt switch provided for each of the plurality of solar array panels and/or solar array panel divisions.   
     
     
         3 . The torque generation system according to  claim 1 , wherein
 the electricity generation ratio is controlled by switching a maximum output state and a shunt state in each of solar cell groups whose regions are smaller than each of the plurality of solar array panels and/or solar array panel divisions.   
     
     
         4 . The torque generation system according to  claim 1 , wherein
 the torque controller puts at least one of the plurality of solar array panels and/or solar array panel divisions in a shunt state.   
     
     
         5 . The torque generation system according to  claim 1 , wherein
 the torque controller puts at least one of the plurality of solar array panels and/or solar array panel divisions in a maximum output state.   
     
     
         6 . The torque generation system according to  claim 1 , wherein
 each of the solar array panels has a light receiving surface significantly higher in temperature than a surface opposites to the light receiving surface of each of the solar array panels during operation.   
     
     
         7 . The torque generation system according to  claim 6 , wherein
 a member with small thermal conductivity is arranged between the light receiving surface of each of the solar array panels and the surface opposite to the light receiving surface of each of the solar array panels.   
     
     
         8 . The torque generation system according to  claim 1 , wherein
 the surface opposite to the light receiving surface is smaller in thermal emissivity than the light receiving surface.   
     
     
         9 . The torque generation system according to  claim 8 , wherein
 the surface opposite to the light receiving surface of each of the solar array panels is coated with aluminum.   
     
     
         10 . An attitude control system for a spacecraft, comprising:
 a plurality of solar array panels and/or solar array panel divisions; and   an attitude controller configured to control an electricity generation ratio of each of the plurality of solar array panels and/or solar array panel divisions to generate torque used to control an attitude of the spacecraft.   
     
     
         11 . The attitude control system according to  claim 10 , wherein
 the electricity generation ratio is controlled by turning on, turning off, or switching a shunt switch provided for each of the plurality of solar array panels and/or solar array panel divisions.   
     
     
         12 . The attitude control system according to  claim 10 , wherein
 the electricity generation ratio is controlled by switching a maximum output state and a shunt state in each of solar cell groups whose regions are smaller than each of the plurality of solar array panels and/or solar array panel divisions.   
     
     
         13 . The attitude control system according to  claim 10 , further comprising
 an attitude detector configured to detect the attitude of the spacecraft; and   a target attitude setting unit configured to set a target attitude of the spacecraft, wherein   the attitude controller controls the electricity generation ratio of each of the plurality of solar array panels and/or solar array panel divisions to generate torque that decreases a difference between a current attitude detected by the attitude detector and the target attitude.   
     
     
         14 . The attitude control system according to  claim 13 , wherein
 the attitude is an attitude angle, and   the attitude controller performs feedback control based on the attitude angle.   
     
     
         15 . The attitude control system according to  claim 13 , wherein
 the target attitude is an attitude whereby the spacecraft points to the sun.   
     
     
         16 . The attitude control system according to  claim 10 , further comprising
 a disturbance torque estimation unit configured to estimate disturbance torque, wherein   the attitude controller controls the electricity generation ratio of each of the plurality of solar array panels and/or solar array panel divisions to generate torque that suppresses the disturbance torque estimated by the disturbance torque estimation unit.   
     
     
         17 . The attitude control system according to  claim 10 , wherein
 the plurality of solar array panels and/or solar array panel divisions are arranged to generate torque for rotating the spacecraft around one predetermined axis.   
     
     
         18 . The attitude control system according to  claim 17 , wherein
 the one predetermined axis extends in a travelling direction of the spacecraft or in a center of the earth direction.   
     
     
         19 . The attitude control system according to  claim 10 , wherein
 the plurality of solar array panels and/or solar array panel divisions are arranged to generate torque for rotating the spacecraft around two predetermined axes, respectively.   
     
     
         20 . The attitude control system according to  claim 19 , wherein
 the two predetermined axes extend in a travelling direction of the spacecraft and in a center of the earth direction.   
     
     
         21 . The attitude control system according to  claim 10 , wherein
 the plurality of solar array panels and/or solar array panel divisions are symmetrically arranged with respect to a body of the spacecraft.   
     
     
         22 . The attitude control system according to  claim 10 , wherein
 each of the solar array panels has a light receiving surface significantly higher in temperature than a surface opposite to the light receiving surface of each of the solar array panels during operation.   
     
     
         23 . The attitude control system according to  claim 22 , wherein
 a member with small thermal conductivity is arranged between the light receiving surface of each of the solar array panels and the surface opposite to the light receiving surface of each of the solar array panels.   
     
     
         24 . The attitude control system according to  claim 10 , wherein
 the surface opposite to the light receiving surface is smaller in thermal emissivity than the light receiving surface.   
     
     
         25 . The attitude control system according to  claim 24 , wherein
 the surface opposite to the light receiving surface of each of the solar array panels is coated with aluminum.   
     
     
         26 . A spacecraft, comprising the attitude control system according to  claim 10 . 
     
     
         27 . A system for controlling a relative position and/or a relative velocity of a first spacecraft and a second spacecraft, comprising:
 the first spacecraft and the second spacecraft each including a solar array panel; and   a relative position and velocity controller configured to control an electricity generation ratio of each of the solar array panels of the first spacecraft and the second spacecraft to cause each of the first spacecraft and the second spacecraft to generate thrust that changes the relative position and/or velocity of the first spacecraft and the second spacecraft.   
     
     
         28 . The system according to  claim 27 , further comprising
 a relative position and velocity setting unit configured to set a target relative position and/or a target relative velocity of the second spacecraft relative to the first spacecraft, wherein   the relative position and velocity controller controls the electricity generation ratio of each of the solar array panels of the first spacecraft and the second spacecraft to cause each of the first spacecraft and the second spacecraft to generate thrust that provides the target relative position and/or target relative velocity set by the relative position and velocity setting unit.   
     
     
         29 . The system according to  claim 27 , wherein
 the first spacecraft and the second spacecraft each includes a position detector configured to detect a position of its own spacecraft and to output position information,   the system further includes a relative position and velocity calculation unit configured to calculate the relative position and/or relative velocity of the second spacecraft relative to the first spacecraft based on the position information from the position detectors of the first spacecraft and the second spacecraft, and   the relative position and velocity controller controls the electricity generation ratio of each of the solar array panels of the first spacecraft and the second spacecraft based on the relative position and/or relative velocity of the second spacecraft relative to the first spacecraft calculated by the position and velocity calculation unit.   
     
     
         30 . The system according to  claim 27 , wherein
 the relative position and velocity controller puts the solar array panel of the second spacecraft in a shunt state.   
     
     
         31 . The system according to  claim 27 , wherein
 the relative position and velocity controller puts the solar array panel of the first spacecraft in a maximum output state.   
     
     
         32 . The system according to  claim 27 , wherein
 each of the solar array panels has a light receiving surface significantly higher in temperature than a surface opposite to the light receiving surface of each of the solar array panels during operation.   
     
     
         33 . The system according to  claim 32 , wherein
 a member with small thermal conductivity is arranged between the light receiving surface of each of the solar array panels and the surface opposite to the light receiving surface of each of the solar array panels.   
     
     
         34 . The system according to  claim 27 , wherein
 the surface opposite to the light receiving surface is smaller in thermal emissivity than the light receiving surface.   
     
     
         35 . The system according to  claim 34 , wherein
 the surface opposite to the light receiving surface of each of the solar array panels is coated with aluminum.   
     
     
         36 . The system according to  claim 27 , wherein
 an attitude of the first spacecraft and/or the second spacecraft is controlled to cause the solar array panels of the first spacecraft and/or the solar array panels of the second spacecraft to point to the sun.