2-pulse gas generator and method of measuring propellant combustion surface position

A 2-pulse gas generator comprising:

• a pressure vessel provided with a combustion space therein;
• a first solid propellant arranged inside the pressure vessel, wherein a first end surface of the first solid propellant is exposed to the combustion space:
• a first igniter configured to ignite the first end surface of the first solid propellant:
• a barrier membrane provided to cover a surface of the first solid propellant other than any combustion surface such that a combustion surface of the first solid propellant moves in a predetermined first direction as combustion of first solid propellant advances,
• a position sensor device configured to detect a position of the combustion surface in the predetermined first direction;
• and
• a processing device configured to estimate a consumption amount of the first solid propellant based on a detection result of the position of the combustion surface,
• wherein the pressure vessel comprises:
• a thruster section configured to exhaust out a combustion gas generated by the combustion of the first solid propellant from the pressure vessel through an area adjustable opening section;
• and
• a pressure sensor device configured to measure a combustion pressure in the combustion space,
• wherein the processing device calculates a setting value of the combustion pressure necessary to combust out the first solid propellant by a desired time based on the detection result of the position of the combustion surface and a measurement result of the combustion pressure,
• wherein the 2-pulse gas generator further comprises:
• a control device configured to adjust the combustion pressure based on the setting value by adjusting an area of the opening section of the thruster section;
• a second solid propellant arranged inside the pressure vessel;
• and
• a second igniter configured to ignite the second solid propellant at the desired time,
• wherein the position sensor device detects the position of the combustion surface in the predetermined first direction at a timing controlled by the control device,
• wherein the pressure sensor device is arranged to oppose the combustion surface across the combustion space, and configured to function as the position sensor device which measures the combustion pressure, and
• wherein the processing device analyzes frequency components of the combustion pressure measured by the pressure sensor device, and calculates a distance from the pressure sensor device to the combustion surface based on a frequency component having the maximum amplitude of the frequency components.

A 2-pulse gas generator comprising:

• a pressure vessel provided with a combustion space therein:
• a first solid propellant arranged inside the pressure vessel, wherein a first end surface of the first solid propellant is exposed to the combustion space;
• a first igniter configured to ignite the first end surface of the first solid propellant;
• a barrier membrane provided to cover a surface of the first solid propellant other than any combustion surface such that a combustion surface of the first solid propellant moves in a predetermined first direction as combustion of first solid propellant advances;
• a position sensor device configured to detect a position of the combustion surface in the predetermined first direction;
• and
• a processing device configured to estimate a consumption amount of the first solid propellant based on a detection result of the position of the combustion surface,
• wherein the pressure vessel comprises:
• a thruster section configured to exhaust out a combustion gas generated by the combustion of the first solid propellant from the pressure vessel through an area adjustable opening section, and
• a pressure sensor device configured to measure a combustion pressure in the combustion space,
• wherein the processing device calculates a setting value of the combustion pressure necessary to combust out the first solid propellant by a desired time based on the detection result of the position of the combustion surface and a measurement result of the combustion pressure,
• wherein the 2-pulse gas generator further comprises:
• a control device configured to adjust the combustion pressure based on the setting value by adjusting an area of the opening section of the thruster section;
• a second solid propellant arranged inside the pressure vessel, and
• a second igniter configured to ignite the second solid propellant at the desired time,
• wherein the position sensor device detects that the combustion surface has reached a predetermined position in the predetermined first direction when the combustion surface has reached the predetermined position in the predetermined first direction,
• wherein the first solid propellant has:
• a second end surface arranged to oppose the first end surface in the predetermined first direction;
• and
• a cavity having one end arranged at the predetermined position in the predetermined first direction, extending in the predetermined first direction to be apart from the first end surface and having an other end reaching the second end surface, and
• wherein the position sensor device comprises a non-contact thermometer arranged at the other end of the cavity, and configured to detect the temperature of the combustion gas when the combustion of the first solid propellant advances so that the combustion surface has reached the predetermined position.

A 2-pulse gas generator comprising:

• a pressure vessel provided with a combustion space therein:
• a first solid propellant arranged inside the pressure vessel, wherein a first end surface of the first solid propellant is exposed to the combustion space;
• a first igniter configured to ignite the first end surface of the first solid propellant;
• a barrier membrane provided to cover a surface of the first solid propellant other than any combustion surface such that a combustion surface of the first solid propellant moves in a predetermined first direction as combustion of first solid propellant advances,
• a position sensor device configured to detect a position of the combustion surface in the predetermined first direction;
• and
• a processing device configured to estimate a consumption amount of the first solid propellant based on a detection result of the position of the combustion surface,
• wherein the pressure vessel comprises:
• a thruster section configured to exhaust out a combustion gas generated by the combustion of the first solid propellant from the pressure vessel through an area adjustable opening section, and
• a pressure sensor device configured to measure a combustion pressure in the combustion space,
• wherein the processing device calculates a setting value of the combustion pressure necessary to combust out the first solid propellant by a desired time based on the detection result of the position of the combustion surface and a measurement result of the combustion pressure,
• wherein the 2-pulse gas generator further comprises:
• a control device configured to adjust the combustion pressure based on the setting value by adjusting an area of the opening section of the thruster section;
• a second solid propellant arranged inside the pressure vessel, and
• a second igniter configured to ignite the second solid propellant at the desired time,
• wherein the position sensor device detects that the combustion surface has reached a predetermined position in the predetermined first direction when the combustion surface has reached the predetermined position in the predetermined first direction, and
• wherein the position sensor device comprises:
• a main unit having airtightness;
• a pressure guiding pipe embedded inside the first solid propellant, and having one end connected with the main unit in an airtight manner and an other end arranged at the predetermined position;
• a piston arranged inside the main unit, and configured to move inside the main unit by the combustion gas flowing into from the other end when the combustion of the first solid propellant advances so that the combustion surface has reached the predetermined position;
• and
• a limit switch arranged inside the main unit, and configured to generate a detection signal based on the movement of the piston, and to transmit to the processing device.

A 2-pulse gas generator comprising:

• a pressure vessel provided to have a combustion space therein;
• a first solid propellant arranged inside the pressure vessel, wherein a first end surface of the first solid propellant is exposed to the combustion space;
• a first igniter configured to ignite the first end surface of the first solid propellant a barrier membrane provided to cover a surface of the first solid propellant other than any combustion surface such that a combustion surface of the first solid propellant moves in a predetermined first direction as the combustion of first solid propellant advances;
• a position sensor device configured to detect a position of the combustion surface in the predetermined first direction;
• and
• a processing device configured to estimate a consumption amount of the first solid propellant based on a detection result of the position of the combustion surface,
• wherein the pressure vessel comprises:
• a thruster section configured to exhaust out a combustion gas generated by the combustion of the first solid propellant from the pressure vessel through an area adjustable opening section;
• and
• a pressure sensor device configured to measure a combustion pressure in the combustion space,
• wherein the processing device calculates a setting value of the combustion pressure necessary to combust out the first solid propellant by a desired time based on the detection result of the position of the combustion surface and a measurement result of the combustion pressure,
• wherein the 2-pulse gas generator further comprises:
• a control device configured to adjust the combustion pressure based on the setting value by adjusting an area of the opening section of the thruster section;
• a second solid propellant arranged inside the pressure vessel;
• and
• a second igniter configured to ignite the second solid propellant at the desired time,
• wherein the position sensor device detects the position of the combustion surface in the predetermined first direction at timing controlled by the control device,
• wherein the first solid propellant comprises:
• a first part having a predetermined first cross sectional area which is an area of a cross section orthogonal to the predetermined first direction;
• and
• a second part having another area of a cross section orthogonal to the predetermined first direction as a second cross sectional area which is different from the predetermined first cross sectional area, and
• wherein the processing device detects a change of the cross sectional area from a change of the measurement result of the combustion pressure.

A method of measuring a propellant combustion surface in a 2-pulse gas generator comprising:

• providing the 2-pulse gas generator, wherein the 2-pulse gas generator comprises:
• a pressure vessel provided with a combustion space therein:
• a first solid propellant arranged inside the pressure vessel, wherein a first end surface of the first solid propellant is exposed to the combustion space;
• a first igniter configured to ignite the first end surface of the first solid propellant:
• a barrier membrane provided to cover a surface of the first solid propellant other than any combustion surface such that a combustion surface of the first solid propellant moves in a predetermined first direction as combustion of first solid propellant advances;
• a position sensor device configured to detect a position of the combustion surface in the predetermined first direction;
• and
• a processing device configured to estimate a consumption amount of the first solid propellant based on a detection result of the position of the combustion surface,
• wherein the pressure vessel comprises:
• a thruster section configured to exhaust out a combustion gas generated by the combustion of the first solid propellant from the pressure vessel through an area adjustable opening section;
• and
• a pressure sensor device configured to measure a combustion pressure in the combustion space,
• wherein the processing device calculates a setting value of the combustion pressure necessary to combust out the first solid propellant by a desired time based on the detection result of the position of the combustion surface and a measurement result of the combustion pressure,
• wherein the 2-pulse gas generator further comprises:
• a control device configured to adjust the combustion pressure based on the setting value by adjusting an area of the opening section of the thruster section;
• a second solid propellant arranged inside the pressure vessel;
• and
• a second igniter configured to ignite the second solid propellant at the desired time,
• wherein the position sensor device detects the position of the combustion surface in the predetermined first direction at a timing controlled by the control device,
• wherein the position sensor device is another pressure sensor device which is comprises a high response pressure sensor arranged to oppose the combustion surface across the combustion space and configured to measure the combustion pressure, and
• wherein the processing device analyzes frequency components of the combustion pressure measured by the high response pressure sensor, and calculates a distance from the high response pressure sensor to the combustion surface based on a frequency component having the maximum amplitude of the frequency components, the method further comprising:
• arranging the first solid propellant inside the pressure vessel and covering the surface of the first solid propellant other than any combustion surface with the barrier membrane such that the combustion surface moves in the predetermined first direction as the combustion of the first solid propellant advances;
• igniting the first solid propellant by the first igniter;
• detecting the position of the combustion surface in the predetermined first direction by the position sensor device;
• and
• estimating the consumption amount of the first solid propellant based on the detection result of the position of the combustion surface by the processing device.