CN209927258U

CN209927258U - Mass measuring instrument under weightlessness state

Info

Publication number: CN209927258U
Application number: CN201921011913.8U
Authority: CN
Inventors: 刘金生; 林瑞初; 凌波; 祝付帅; 牛岩; 赵东明; 李长福; 杨伟浩; 孔方舟; 马永洁; 张玉梅; 高美萍; 肖咏捷
Original assignee: China University of Metrology; China Astronaut Research and Training Center
Current assignee: China University of Metrology; China Astronaut Research and Training Center
Priority date: 2019-07-01
Filing date: 2019-07-01
Publication date: 2020-01-10
Anticipated expiration: 2029-07-01

Abstract

The utility model discloses a mass measuring instrument under weightless state, which comprises a measuring instrument host, a bearing bracket and a base mounting rack; the measuring instrument host is provided with a vibration free end and a mounting fixed end; the installation stiff end with base mounting bracket fixed connection, the vibration free end with bearing support swing joint, bearing support with the relative position of vibration free end is followed the vibration direction of vibration free end is fixed unchangeable, bearing support with the relative position of vibration free end is followed the perpendicular to the vibration direction of vibration free end is variable. The utility model discloses structural design is compact, light in weight, reliable operation, can realize the accurate measurement of human body or other object quality under the weightless condition.

Description

Mass measuring instrument under weightlessness state

Technical Field

The utility model relates to a space flight measurement technical field. In particular to a mass measuring instrument under the weightless state.

Background

Because the gravity does not exist, the human body mass of astronauts measured in the space weightless environment is greatly different from that of the astronauts measured on the ground, and the general weighing scale cannot be used for measurement. The idea of measuring the mass under the weightless environment is to move an object and measure the mass by measuring the physical quantity parameters related to the mass when the object moves. At present, the main methods for domestic and foreign research can be divided into three categories: spring oscillator principle, newton's second law, momentum theorem.

Compared with a method for measuring mass by using a vibration principle, the method for measuring mass by using the Newton's second law has the advantages that the method is small in non-rigid influence of an object and high accuracy is easily obtained, but for uniform acceleration linear motion, the motion stroke is short, a control device is required to stably move, and acceleration is difficult to accurately measure. If circular motion is adopted, the required space is large, and the circular motion type air-conditioning system is not suitable for narrow spaces such as space stations, airships and the like.

The method for measuring the mass by the momentum theorem still stays at the conceptual stage at present, and on-orbit verification is not carried out, the method has many difficulties that ① generally needs to measure two quantities of force and speed at the same time, and higher requirements are provided for measurement, ② generally generates collision, discomfort can be generated for human body measurement, non-rigid body irregular motion can be generated due to the collision, and the measurement of the speed and the force is influenced, ③ the collision process needs to strictly control the motion and the friction, and certain difficulty is realized.

SUMMERY OF THE UTILITY MODEL

Therefore, the technical problem to be solved by the present invention is to provide a mass measuring instrument under weightless state.

In order to solve the technical problem, the utility model provides a following technical scheme:

the mass measuring instrument under the weightlessness state comprises a measuring instrument host (100), a bearing support and a base mounting rack (1); the measuring instrument main body (100) is provided with a vibration free end and an installation fixed end; the installation stiff end with base mounting bracket (1) fixed connection, the vibration free end with bearing support swing joint, bearing support with the relative position of vibration free end is followed the vibration direction of vibration free end is fixed unchangeable, bearing support with the relative position of vibration free end is followed the perpendicular to the vibration direction of vibration free end is variable.

According to the mass measuring instrument in the weightless state, the bearing support comprises a support main body, and a connecting bearing seat (11) and an anti-rotation pin (14) are mounted on the vibration free end; the support trunk passes the hole (13) that floats from top to bottom on connecting bearing frame (11), and seted up on the surface of support trunk along the spout (12) that floats from top to bottom of support trunk axis direction, prevent that the one end of rotating pin (14) passes pinhole on connecting bearing frame (11) and stretch into in the spout (12) that floats from top to bottom, prevent rotating pin (14) with threaded connection between connecting bearing frame (11).

The mass measuring instrument under the weightlessness state is characterized in that the main machine (100) of the measuring instrument comprises a base (01), a bracket (09), a fixing ring (06), a spring vibration mechanism, a rotation limiting mechanism and a period calculating mechanism; the two ends of the support (09) are respectively fixedly connected with the base (01) and the fixing ring (06), the bottom of the spring vibration mechanism is fixedly installed on the base (01), the top of the spring vibration mechanism penetrates through the fixing ring (06), the rotation limiting mechanism comprises a fixed limiting part and a movable guiding part, the movable guiding part is fixedly installed on the spring vibration mechanism, and the fixed limiting part is fixedly installed on the support (09); the cycle calculating mechanism comprises a fixed part and a movable part, the fixed part of the cycle calculating mechanism is arranged on the bracket (09), and the movable part of the cycle calculating mechanism is arranged on the spring vibration mechanism.

The mass measuring instrument under the weightless state comprises a spring (02), a flange (03), a linear optical axis (04) and a linear flange bearing (05); the bottom of the spring (02) is fixedly arranged on the base (01), the top of the spring (02) is fixedly arranged on the lower bottom surface of the flange (03), and the bottom of the linear optical axis (04) is fixedly arranged on the upper surface of the flange (03); the flange portion of straight line flange bearing (05) with retainer plate (06) pass through bolt fixed connection, the bearing portion of straight line flange bearing (05) is located base (01) with between retainer plate (06), the top of sharp optical axis (04) is passed the shaft hole of straight line flange bearing (05) and towards keeping away from the direction of the bearing portion of straight line flange bearing (05) stretches out, flange (03) with spring (02) are located base (01) with between the bearing portion of straight line flange bearing (05).

According to the mass measuring instrument in the weightless state, the base (01) and the flange (03) are respectively provided with an annular mounting groove (01-1), the outer diameter of the annular mounting groove (01-1) is equal to the outer diameter of the spring (02), the inner diameter of the annular mounting groove (01-1) is equal to the inner diameter of the spring (02), and the bottom end of the spring (02) is fixedly mounted in the annular mounting groove (01-1).

In the mass measuring instrument under the weightless state, the base (01) and the flange (03) are respectively provided with four linear clamping pieces (01-2) crossing the annular mounting groove (01-1), and the four linear clamping pieces (01-2) are distributed at equal intervals along the circumferential direction of the annular mounting groove (01-1).

In the mass measuring instrument in the weightless state, the fixed limiting component is a sliding chute track (010) with a linear sliding chute, the movable guiding component comprises a rolling shaft (011-1) and a guiding wheel (011-2), one end of the rolling shaft (011-1) is fixedly arranged on the spring vibration mechanism through a shaft cover (014), the guiding wheel (011-2) is positioned in the linear sliding chute of the sliding chute track (010), and the guiding wheel (011-2) is arranged at the other end of the rolling shaft (011-1) through a bearing; the sliding groove rail (010) is installed on one side face, facing the spring vibration mechanism, of the support (09), and a linear sliding groove in the sliding groove rail (010) is parallel to the reciprocating direction of the spring vibration mechanism.

In the mass measuring instrument in the weightless state, the fixed part of the period calculating mechanism is a correlation photoelectric sensor (012), and the moving part of the period calculating mechanism is a shading plate (015); one end of the light screen (015) is fixedly arranged on the spring vibration mechanism, and the other end of the light screen (015) reciprocates between the emitting end (07) and the receiving end (08) of the correlation photoelectric sensor (012) along with the movement of the spring vibration mechanism; the support (09) is a linear vertical plate, and the linear vertical plate and the base (01) as well as the linear vertical plate and the fixed ring (06) are fixedly connected through right-angle connecting pieces (013); the number of the linear vertical plates is four, and the linear vertical plates are distributed at equal intervals along the circumferential direction of the spring vibration mechanism; the fixing ring (06) comprises a fixing ring (06-1) and four fixing arms (06-2), wherein the four fixing arms (06-2) are distributed at equal intervals along the circumferential direction of the fixing ring (06-1) and are respectively fixedly connected with the fixing ring (06-1); the stiffness of the spring (02) is: when the total mass m weighed was 90kg, the period of vibration T of the spring was 1.75-2.25 s.

The mass measuring instrument under the weightlessness state further comprises an optical platform (2), an air floating platform (3) and an air floating block (17), wherein the base mounting frame (1) and the air floating platform (3) are respectively and fixedly mounted on the upper surface of the optical platform (2), and the air floating block (17) is fixedly mounted at the bottom of the bearing support; the weight support is a weight support (15), the weight support (15) comprises a weight support chassis (15-1), a weight support trunk (15-2), a threaded rod (15-3) and a weight pressure plate (15-4), the bottom end of the weight support trunk (15-2) is fixedly installed on the weight support chassis (15-1), one end of the threaded rod (15-3) is in threaded connection with the weight support trunk (15-2), and the other end of the threaded rod (15-3) is in threaded connection with the weight pressure plate (15-4); the air floating block (17) is fixedly arranged on the lower bottom surface of the weight support chassis (15-1); the threaded rod (15-3) comprises a vertical mounting threaded rod, a first horizontal mounting threaded rod and a second horizontal mounting threaded rod, and the lower end of the vertical mounting threaded rod extends into an axial middle hole in the top end of the weight support trunk (15-2) and is in threaded connection with the weight support trunk (15-2); the first horizontal installation threaded rod and the second horizontal installation threaded rod are parallel to the ground and coaxially located on two sides of the weight support trunk (15-2).

The mass measuring instrument under the weightlessness state further comprises an optical platform (2), an air floating platform (3) and an air floating block (17), wherein the base mounting frame (1) and the air floating platform (3) are respectively and fixedly mounted on the upper surface of the optical platform (2), and the air floating block (17) is fixedly mounted at the bottom of the bearing support; the bearing support is a human body support (4), the human body support (4) comprises a human body support chassis (5), a seat flat plate (6), a seat rod (7), a human body support main body (8), a hand and foot support (9) and a chest support (10), the bottom end of the human body support main body (8) and the bottom end of the seat rod (7) are fixedly installed on the upper surface of the human body support chassis (5) respectively, the seat flat plate (6) is fixedly installed at the top end of the seat rod (7), the hand and foot support (9) and the chest support (10) are fixedly installed on the human body support main body (8) respectively, and the air floating block (17) is fixedly installed on the lower bottom surface of the human body support chassis (5); the air floating blocks (17) are composed of a first air floating block, a second air floating block and a third air floating block, and the first air floating block, the second air floating block and the third air floating block are fixedly arranged on the lower bottom surface of the human body support chassis (5) at equal intervals along the same circumference; the hand and foot support (9) consists of an upper hand and foot support, a middle hand and foot support and a lower hand and foot support, the upper hand and foot support is fixedly arranged at the upper end of the human body support main body (8), the lower hand and foot support is fixedly arranged at the lower end of the human body support main body (8), the middle hand and foot support is fixedly arranged on the human body support main body (8) between the upper hand and foot support and the lower hand and foot support, and the chest support (10) is fixedly arranged on the human body support main body (8) between the middle hand and foot support and the lower hand and foot support; the base mounting frame (1) comprises a first longitudinal aluminum section, a second longitudinal aluminum section, a third longitudinal aluminum section, a fourth longitudinal aluminum section, a first transverse aluminum section and a second transverse aluminum section, the first longitudinal aluminum section, the second longitudinal aluminum section, the third longitudinal aluminum section and the fourth longitudinal aluminum section are respectively and fixedly mounted on the upper surface of the optical platform (2), and four side surfaces of the bottom end of the first longitudinal aluminum section, four side surfaces of the bottom end of the second longitudinal aluminum section, four side surfaces of the bottom end of the third longitudinal aluminum section and four side surfaces of the bottom end of the fourth longitudinal aluminum section are respectively and fixedly connected with the optical platform (2) through aluminum section corner pieces; the two ends of the first transverse aluminum section are fixedly connected with the first longitudinal aluminum section and the second longitudinal aluminum section through aluminum section corner pieces respectively, and the two ends of the second transverse aluminum section are fixedly connected with the third longitudinal aluminum section and the fourth longitudinal aluminum section through aluminum section corner pieces respectively; the upper hand and foot support, the middle hand and foot support and the lower hand and foot support penetrate through mounting holes in the human body support trunk (8), and the upper hand and foot support, the middle hand and foot support and the lower hand and foot support are parallel to each other; one end of the chest support (10) penetrates through a mounting hole in the human body support main body (8) and extends towards the position right above the seat flat plate (6), and the chest support (10) is perpendicular to the upper hand and foot support.

The technical scheme of the utility model following profitable technological effect has been obtained:

1. the matching design of the linear optical axis and the linear flange bearing ensures that the linear optical axis can run very stably, the measurement accuracy and precision are improved, and the noise is extremely low during measurement.

2. The linear flange bearing can be very conveniently and fixedly installed together with the fixed ring through the flange at one end of the linear flange bearing, so that the linear flange bearing and the fixed ring are stably installed together, and a reciprocating motion track is better provided for a linear optical axis.

3. Annular mounting grooves are respectively formed in the base and the flange, and one end of the spring is fixed in the annular mounting groove through a linear clamping piece; the two ends of the spring are ensured to be stably connected, and the spring can be stretched or compressed along the axial direction during measurement, so that the transverse deviation can not occur, the reliability and the accuracy of a measurement result are ensured, different springs can be conveniently replaced when the rigidity of the spring is changed, and the installation mode is favorable for quick disassembly and installation of a host.

4. The cooperation of spout track, rolling shaft and leading wheel is used, can ensure well that spring and straight line optical axis are reciprocating linear motion together to can eliminate the radial slight skew that probably causes the spring under straight line optical axis and the long-term user state of straight line flange bearing.

5. The correlation photoelectric sensor is matched with the light screen to conveniently detect the vibration of the spring oscillator, so that the period of the spring oscillator is calculated.

6. Fixed frame is constituteed to base, support, retainer plate, and the spring both ends are fixed respectively in base and sharp optical axis one end, adopt linear bearing and sharp optical axis complex mode for spring oscillator system is linear motion along sharp optical axis axial, and spring oscillator system motion is steady, small in noise. The device has compact structural design, light weight and reliable work, and can realize accurate measurement of the human body mass under the condition of weightlessness.

7. The method can simulate the space weightlessness environment on the ground, is used for testing the application reliability and accuracy of the mass measuring instrument in the weightlessness state, and is used for assisting the design and manufacture of the mass measuring instrument in the weightlessness state, thereby accelerating the research and development progress of practical application.

8. When the quality measuring instrument is tested, a test subject can sit on the seat flat plate, the chest leans against the chest support, and the two arms respectively surround the upper hand-foot support from the lower direction of the upper hand-foot support at the two sides of the human body support trunk, so that the two hands are respectively arranged at the two sides of the chin; the two legs respectively surround the middle hand and foot support from the upper part of the middle hand and foot support at the two sides of the main body of the human body support downwards, the foot surfaces are propped against the lower hand and foot support, and the elbows are arranged on the two legs; the structural design of the human body support enables a testee to keep a relatively stable posture for quality test, and errors caused by the change of the gravity center of the testee in the test process are reduced.

9. The base mounting frame is simple in structure and easy to assemble and form, used parts can be directly purchased from the market, the manufacturing cost of the test platform is reduced, and the base mounting frame is stable and reliable.

10. The design of the connecting bearing seat, the rotation preventing pin and the up-and-down floating sliding groove can enable the human body support to float up and down (the human body support trunk and the up-and-down floating hole are in clearance fit), the up-and-down floating sliding groove and the rotation preventing pin can enable the human body support to always keep vertical reciprocating motion, rotation or deviation can not occur in the up-and-down floating process, and therefore the human body support is well suitable for measurement of subjects with different qualities.

Drawings

Fig. 1 is a schematic diagram of a main machine structure of the mass measuring instrument in a weightless state;

fig. 2 is a schematic view of another direction structure of the main unit of the mass measuring instrument in the weightless state of the present invention shown in fig. 1;

fig. 3 is a schematic diagram of a main structure of the mass measuring instrument in a weightless state (neither the linear flange bearing nor the fixing ring is shown);

fig. 4 is a schematic view showing another direction structure of the main unit of the mass measuring instrument in the weightless state of the present invention (the linear flange bearing and the fixing ring are not shown);

fig. 5 is a schematic view of another form of the main machine of the mass measuring instrument in the weightless state (different structures of the fixing rings);

fig. 6 is a schematic structural view of the mass measuring instrument used in the weightless state of the present invention;

fig. 7 is a schematic structural view of a middle rotation prevention pin of the mass measuring instrument in a weightless state;

fig. 8 is a schematic structural view of a middle connection bearing seat of the mass measuring instrument in a weightless state;

fig. 9 is a schematic structural view of the mass measuring instrument of the present invention in a weightless state (neither the optical platform nor the air-float platform is shown);

fig. 10 is a schematic structural view of a weight holder of the mass measuring instrument of the present invention in a weightless state;

FIG. 11 weight mass absolute error measurement;

fig. 12 weight mass measures relative error.

The reference numbers in the figures denote: 01-a base; 01-1-an annular mounting groove; a 01-2-in-line clip; 02-a spring; 03-a flange; 04-straight optical axis; 05-linear flange bearing; 06-a fixing ring; 06-1-a fixed ring; 06-2-fixed arm; 07-a transmitting end; 08-receiving end; 09-a scaffold; 010-a chute track; 011-1-rolling axis; 011-2-guide wheels; 012-correlation photoelectric sensor; 014-shaft cover; 013-right angle connectors; 015-visor; 016-mounting plate.

Detailed Description

The mass measuring instrument in the weightless state of the embodiment comprises a measuring instrument host 100, an optical platform 2, an air floatation platform 3, an air floatation block 17, a bearing support and a base mounting frame 1; the base mounting frame 1 and the air floating platform 3 are respectively and fixedly mounted on the upper surface of the optical platform 2, and the air floating block 17 is fixedly mounted at the bottom of the bearing support; the gauge main body 100 has a vibration free end and a mounting fixed end; the installation stiff end with 1 fixed connection of base mounting bracket, the vibration free end with bearing support swing joint, bearing support with the relative position of vibration free end is followed the vibration direction of vibration free end is fixed unchangeable, bearing support with the relative position of vibration free end is followed the perpendicular to the vibration direction of vibration free end is variable. The bearing support comprises a support main body, and a connecting bearing seat 11 and an anti-rotation pin 14 are arranged on the free end of the vibration; the bracket trunk penetrates through a vertical floating hole 13 in the connecting bearing seat 11, a vertical floating sliding groove 12 along the axial direction of the bracket trunk is formed in the outer surface of the bracket trunk, one end of the rotation preventing pin 14 penetrates through a pin hole in the connecting bearing seat 11 and extends into the vertical floating sliding groove 12, and the rotation preventing pin 14 is in threaded connection with the connecting bearing seat 11.

As shown in fig. 1 to 5, the main unit 100 of the mass measuring instrument in the weightless state of the present embodiment includes a base 01, a bracket 09, a fixing ring 06, a spring vibration mechanism, a rotation limiting mechanism, and a period calculating mechanism; the two ends of the support 09 are respectively fixedly connected with the base 01 and the fixing ring 06, the bottom of the spring vibration mechanism is fixedly installed on the base 01, the top of the spring vibration mechanism penetrates through the fixing ring 06, the rotation limiting mechanism comprises a fixed limiting part and a movable guiding part, the movable guiding part is fixedly installed on the spring vibration mechanism, and the fixed limiting part is fixedly installed on the support 09; the cycle calculating mechanism includes a fixed member and a moving member, the fixed member of the cycle calculating mechanism is mounted on the bracket 09, and the moving member of the cycle calculating mechanism is mounted on the spring vibrating mechanism.

In this embodiment, the spring vibration mechanism includes a spring 02, a flange 03, a linear optical axis 04, and a linear flange bearing 05; the bottom of the spring 02 is fixedly arranged on the base 01, the top of the spring 02 is fixedly arranged on the lower bottom surface of the flange 03, and the bottom of the linear optical axis 04 is fixedly arranged on the upper surface of the flange 03; the flange part of straight line flange bearing 05 with retainer plate 06 passes through bolt fixed connection, the bearing part of straight line flange bearing 05 is located the base 01 with between the retainer plate 06, the top of sharp optical axis 04 passes the shaft hole of straight line flange bearing 05 and to keeping away from the direction of the bearing part of straight line flange bearing 05 stretches out, flange 03 with spring 02 is located the base 01 with between the bearing part of straight line flange bearing 05.

The base 01 and the flange 03 are respectively provided with an annular mounting groove 01-1, the outer diameter of the annular mounting groove 01-1 is equal to the outer diameter of the spring 02, the inner diameter of the annular mounting groove 01-1 is equal to the inner diameter of the spring 02, and the bottom end of the spring 02 is fixedly mounted in the annular mounting groove 01-1. And the base 01 and the flange 03 are respectively provided with four linear clamping pieces 01-2 crossing the annular mounting groove 01-1, and the four linear clamping pieces 01-2 are distributed at equal intervals along the circumferential direction of the annular mounting groove 01-1.

The fixed limiting component is a sliding groove track 010 with a linear sliding groove, the movable guiding component comprises a rolling shaft 011-1 and a guide wheel 011-2, one end of the rolling shaft 011-1 is fixedly installed on the spring vibration mechanism through a shaft cover 014, the guide wheel 011-2 is located in the linear sliding groove of the sliding groove track 010, and the guide wheel 011-2 is installed on the other end of the rolling shaft 011-1 through a bearing. The sliding groove rail 010 is installed on a side surface of the bracket 09 facing the spring vibration mechanism, and a linear sliding groove on the sliding groove rail 010 is parallel to a reciprocating direction of the spring vibration mechanism. The fixed part of the period calculation mechanism is a correlation photoelectric sensor 012, and the moving part of the period calculation mechanism is a light shielding plate 015; one end of the light shielding plate 015 is fixedly mounted on the spring vibration mechanism, and the other end of the light shielding plate 015 reciprocates between the emitting end 07 and the receiving end 08 of the correlation photoelectric sensor 012 along with the movement of the spring vibration mechanism. The support 09 is a linear vertical plate, and the linear vertical plate is fixedly connected with the base 01 and the fixed ring 06 through right-angle connecting pieces 013. The number of the linear vertical plates is four, and the linear vertical plates are distributed at equal intervals along the circumferential direction of the spring vibration mechanism. The stiffness of the spring 02 is: when the total mass m weighed was 90kg, the period of vibration T of the spring was 1.75-2.25 s.

As shown in fig. 6 to 10, before measuring the mass of a human body or other objects, the mass measuring instrument is first checked with a standard weight. As shown in fig. 10, the bearing support is a weight support 15 specially used for standard weight measurement, the weight support 15 includes a weight support chassis 15-1, a weight support trunk 15-2, a threaded rod 15-3 and a weight platen 15-4, the bottom end of the weight support trunk 15-2 is fixedly mounted on the weight support chassis 15-1, one end of the threaded rod 15-3 is in threaded connection with the weight support trunk 15-2, and the other end of the threaded rod 15-3 is in threaded connection with the weight platen 15-4; the air floating block 17 is fixedly arranged on the lower bottom surface of the weight support chassis 15-1. The threaded rod 15-3 comprises a vertical mounting threaded rod, a first horizontal mounting threaded rod and a second horizontal mounting threaded rod, and the lower end of the vertical mounting threaded rod extends into an axial middle hole at the top end of the weight support trunk 15-2 and is in threaded connection with the weight support trunk 15-2; the first horizontal installation threaded rod and the second horizontal installation threaded rod are parallel to the ground and coaxially located on two sides of the weight support trunk 15-2. When the standard weight is used for testing the mass measuring instrument, the weight pressure plate 15-4 is detached from the threaded rod 15-3, the threaded rod 15-3 is sleeved with the standard weight with a central hole, then the weight pressure plate 15-4 is installed, and the standard weight is tightly pressed on the weight support trunk 15-2 after being screwed down, so that the position stability of the standard weight can be ensured. The first horizontal mounting threaded rod, the second horizontal mounting threaded rod and the vertical mounting threaded rod are arranged to measure the mass of an object with the center of gravity on the axis 15-2 of the weight support trunk or deviating from the axis 15-2 of the weight support trunk.

As shown in fig. 6 to 9, the bearing support is a human body support 4, the human body support 4 includes a human body support chassis 5, a seat plate 6, a seat rod 7, a human body support trunk 8, a hand and foot support 9 and a chest support 10, the bottom end of the human body support trunk 8 and the bottom end of the seat rod 7 are respectively and fixedly installed on the upper surface of the human body support chassis 5, the seat plate 6 is fixedly installed on the top end of the seat rod 7, the hand and foot support 9 and the chest support 10 are respectively and fixedly installed on the human body support trunk 8, and the air floating block 17 is fixedly installed on the lower bottom surface of the human body support chassis 5.

The air floating block 17 is composed of a first air floating block, a second air floating block and a third air floating block, and the first air floating block, the second air floating block and the third air floating block are fixedly installed on the lower bottom surface of the human body support chassis 5 at equal intervals along the same circumference. High-pressure gas enters the air floating block 17 from an air inlet on one side of the air floating block 17, then is sprayed onto the upper surface of the air floating platform 3 from the bottom of the air floating block 17, the reaction force is utilized to counteract the gravity of a measured object or a human body, the space weightless environment is simulated, the mass of the measured object or the human body is measured, and therefore the inspection of the mass measuring instrument in the weightless state is realized.

The hand and foot support 9 comprises an upper hand and foot support, a middle hand and foot support and a lower hand and foot support, the upper hand and foot support is fixedly installed at the upper end of the human body support main body 8, the lower hand and foot support is fixedly installed at the lower end of the human body support main body 8, the middle hand and foot support is fixedly installed at the upper hand and foot support and between the lower hand and foot support and on the human body support main body 8, and the chest support 10 is fixedly installed at the middle hand and foot support and between the lower hand and foot support and on the human body support main body 8.

The base mounting frame 1 comprises a first longitudinal aluminum profile 1-1, a second longitudinal aluminum profile 1-2, a third longitudinal aluminum profile 1-3, a fourth longitudinal aluminum profile 1-4, a first transverse aluminum profile 1-5 and a second transverse aluminum profile 1-6, wherein the first longitudinal aluminum profile 1-1, the second longitudinal aluminum profile 1-2, the third longitudinal aluminum profile 1-3 and the fourth longitudinal aluminum profile 1-4 are respectively and fixedly mounted on the upper surface of the optical platform 2, and four side surfaces of the bottom end of the first longitudinal aluminum profile, four side surfaces of the bottom end of the second longitudinal aluminum profile, four side surfaces of the bottom end of the third longitudinal aluminum profile and four side surfaces of the bottom end of the fourth longitudinal aluminum profile are respectively and fixedly connected with the optical platform 2 through aluminum profile corner pieces 16; the two ends of the first transverse aluminum profiles 1-5 are fixedly connected with the top ends of the first longitudinal aluminum profiles and the second longitudinal aluminum profiles through aluminum profile corner fittings 16 respectively, and the two ends of the second transverse aluminum profiles 1-6 are fixedly connected with the top ends of the third longitudinal aluminum profiles and the top ends of the fourth longitudinal aluminum profiles through aluminum profile corner fittings 16 respectively. Base mounting bracket 1 adopts the aluminium alloy equipment of above-mentioned structural style, can provide stable installation fixed bolster for quality measurement appearance on the one hand, and the another side can be installed fixedly from the aluminium alloy of direct purchase corresponding specification in market, need not design the base mounting bracket alone, not only reduce cost, simple to operate moreover, whole weight is little.

The human body support trunk 8 passes through the hole 13 that floats from top to bottom on the connecting bearing seat 11, and set up on the surface of human body support trunk 8 along the spout 12 that floats from top to bottom of the 8 axis directions of human body support trunk, prevent that the one end of rotating pin 14 passes pinhole on the connecting bearing seat 11 and stretch into in the spout 12 that floats from top to bottom, prevent rotating pin 14 with threaded connection between the connecting bearing seat 11.

The upper scaffold, the middle scaffold and the lower scaffold all pass through mounting holes in the human body support trunk 8, and the upper scaffold, the middle scaffold and the lower scaffold are parallel to each other and perpendicular to the human body support trunk 8; one end of the chest support 10 passes through a mounting hole on the human body support trunk 8 and extends towards the right upper part of the seat flat plate 6, and the chest support 10 is perpendicular to the upper hand and foot support.

When the quality measuring instrument is tested on the ground, a test subject sits on the seat flat plate 6, the chest leans against the chest support 10, and the two arms respectively surround the upper hand-foot support from the lower part of the upper hand-foot support at the two sides of the human body support trunk 8, so that the two hands are respectively arranged at the two sides of the chin; the two legs respectively surround the middle hand and foot support from the upper part of the middle hand and foot support at the two sides of the human body support main body 8 downwards, the foot surfaces are propped against the lower hand and foot support, and the elbows are arranged on the two legs; the structural design of the human body support enables a testee to keep a relatively stable posture for quality test, and errors caused by the change of the gravity center of the testee in the test process are reduced.

The design of the connecting bearing seat 11, the anti-rotation pin 14 and the up-and-down floating sliding groove 12 can enable the human body support to float up and down (the human body support trunk 8 and the up-and-down floating hole 13 are in clearance fit), the up-and-down floating sliding groove 12 and the anti-rotation pin 14 can enable the human body support to always keep vertical reciprocating motion, rotation or deviation cannot occur in the up-and-down floating process, and therefore the human body support is well suitable for measurement of subjects with different qualities.

When the quality measuring instrument of this embodiment carries out the inspection test on ground under the weightless state, transversely install and place: the spring 02 and the linear optical axis 04 are parallel to the ground, a measured object is fixedly connected with the linear optical axis 04 through a mounting disc 016 fixed on one end of the linear optical axis 04, the gravity of the measured object is balanced through an air floatation device (due to the existence of the gravity, the ground test is different from the test condition in a weightless state in space, the spring is flattened so as not to work normally when the spring is placed vertically, and the friction resistance is inevitably generated when the spring is placed horizontally, in order to achieve the performance test and analysis of the spring vibrator quality measuring device on the ground, a host machine is placed horizontally and operates, a weightlessness experiment platform can be simulated on the air floatation device for testing, at the moment, the weight of the measured object is offset by an air floatation block of the air floatation device, the measured weight moves horizontally, the friction is approximate to 0, and the measurement range, the measurement error and the like of the host machine can be evaluated), therefore, the tested object, the linear optical axis 04 and the spring 02 form the spring vibrator, the stiffness coefficient of the spring 02 is known, and the mass of the tested object can be calculated by testing the vibration period of the spring vibrator. The opposite-emitting photoelectric sensor is also called a groove-shaped optical coupler, and two pins (namely an emitting end 07 and a receiving end 08) of the groove respectively emit and receive infrared light sources. The working voltage is 5V, and the output is a single-path signal output. When there is no shielding in the groove, the output is low level, and when the emitted light source is blocked by the light shielding plate 015 and cannot be received, the output signal is high level. The shading plate 015 can shield the light source by following the continuous up-and-down back and forth movement of the spring 02, and the vibration frequency of the spring can be determined by measuring an output signal, wherein the signal acquisition is realized by an NIUSB-6008 data acquisition card. The shutter plate 015 produces a pulse each time it passes through the equilibrium position, with 4 cycles between the 1 st pulse and the 9 th pulse, and the measured period T is the time divided by 4.

Technical scheme and technical principle

1.1 basic principles and major design considerations

According to the formula of the vibration period of the spring oscillator systemThe object quality can be obtained

Where k is the spring rate and T is the vibration period.

According to the formula (1), under the condition that the spring stiffness is constant, the mass measurement of a human body or other objects in a weightless state can be carried out as long as the vibration period is measured. In order to achieve the goal that the developed device measures accurately and reliably and complete the performance evaluation of the device on the ground, the technical scheme of the embodiment takes the following 3 aspects into consideration:

(1) keeping the spring rate constant. The formula (1) assumes that k is constant, and to meet the requirement, the spring selection and the device structure design need to be guaranteed. The spring that accords with quality standard is selected, and the rigidity that spring and base are connected is guaranteed to structural design, guarantees spring linear motion stability, avoids transversely rocking. In addition, the spring stiffness self-calibration can be conveniently carried out in the actual test.

(2) The vibration period is ensured to be measured accurately. With k constant, the only thing that needs to be measured is the period of vibration T. If the measured mass is 40kg and the measurement accuracy is 0.2kg, the error is 0.5%, and the time measurement accuracy needs to be better than 0.25%. If the time measurement accuracy design target is 0.2%, m is 40kg, and the measurement resolution is 0.1kg, the vibration period is 1s, and the measurement accuracy of the vibration period should be 1 ms.

(3) And evaluating the performance of the device under the ground condition. Due to the existence of gravity, the ground test is different from the test condition in a weightless state in space, the spring can be flattened so as not to normally work when the spring is vertically placed, and the friction resistance is inevitably generated when the spring is horizontally placed. How to perform experiments on the ground to trace the source of the device quality measurements and obtain the uncertainty of the device measurements? In order to test and analyze the performance of the spring oscillator human body mass measuring device on the ground, the weighing device developed by the patent can be horizontally placed and operated, and can be tested on an air floatation simulated weightlessness experiment platform. At the moment, the weight of the measured object is offset by the air floatation block, the measured weight moves horizontally, the friction force is approximate to 0, and the measuring range, the measuring error and the like of the device can be evaluated.

1.2 device design

The vibration direction of the weighing device is axial, the spring 02 is arranged on the base 01, and the spring 02 and the linear optical axis 04 are connected through the flange 03. A linear flange bearing 05 is used for limiting the linear optical axis 04 to vibrate back and forth along the axial direction, and a smooth sliding groove track 010 is used for limiting the rotation of the linear optical axis 04. The linear flange bearing 05 is fixed to the base 01 by four brackets 09 and a fixing ring 06. One end of the linear optical axis 04 is connected with a bearing support, and the bearing support is used for additionally mounting weights or bearing a human body and the like.

An opposite photoelectric sensor 012 is arranged on a support 09, a shading plate 015 is arranged on a flange 03 connected with a linear optical axis 04, the shading plate 015 is driven by the vibration of the linear optical axis 04 to generate a high-level signal every time the shading plate 015 passes through the opposite photoelectric sensor 012, the square-wave periodic signal is formed by reciprocating vibration, the period of the square-wave signal is detected to obtain the vibration period T of the spring oscillator, and the measured mass m can be obtained by the calculation of a formula (1).

The parts of the device are as follows:

① base 01. the material of base 01 is an aluminum plate with length and width of 200mm, respectively, and thickness of 20mm, all parts are installed on the base 01 as the base, digging an annular installation groove 01-1 with middle diameter of phi 56mm, width of 4.5mm, and depth of 3.8mm on the base 01 for installing spring 02, punching 3M 4 threaded holes on the edges of four sides for installing support 09, respectively punching a phi 7mm through hole on four corners of the base 01 for installing the base 01 and the whole device on the base installation frame 1, the ground or other platforms.

② spring 02, wherein the spring 02 is the key part of the whole system, the lower end of the spring 02 is fixed on the base 01, the upper end is connected with the straight line optical axis 04 which can move up and down, for the whole vibration system, the rigidity of the spring 02 is selected to be crucial, through the multi-test and device optimization design, the measurement mass range is 40-100kg, the measurement precision is 0.2kg, and the measurement resolution is 0.1kg, the spring rigidity design requirement is that when the total mass m of the weighing is 90kg, the vibration period T of the spring is best 2s, and the formula is as follows:

the target stiffness of the spring can be calculated to be 888N/m. For a typical helical spring rate, it can be calculated from equation (3):

wherein G is the shear modulus of the spring steel and is 78GPa, D is the wire diameter of the spring, n is the coil number of the spring, and D is the intermediate diameter of the spring.

③ Flange 03, flange 03 is an aluminum plate with diameter phi 90mm and thickness 10mm, flange 03 is used to connect spring 02 and linear optical axis 04, one side of flange 03 is dug an annular mounting groove 01-1 with middle diameter 56mm, width 4.5mm and depth 3.8mm for fixing spring 02, 4 through holes with phi 5.5mm are drilled on flange 03, flange 03 is connected with linear optical axis 04 by bolts.

④ Linear optical axis 04 the purpose of the linear optical axis 04 is to use the linear optical axis 04 to move back and forth in the linear flange bearing 05 along the straight line with small friction force, the size of the shaft is 40mm outside diameter, 8mm wall thickness and 310mm length, the length of the shaft is selected according to the length of the linear flange bearing 05 and the amplitude of the spring 02, 4M 5 screw holes are drilled on the ring section of the two sides of the shaft, one end is used to connect the flange 03 and the spring 02, the other end is connected with the bearing bracket, the heavy object can be placed on the bearing bracket.

⑤ Linear flange bearing 05, the model of flange bearing is LMF40LUU, the total length of the flange bearing is 154mm, the inner diameter and outer diameter of the bearing part are phi 40mm and phi 60mm respectively, the thickness of the flange part is 13mm, the outer diameter is phi 96mm, the position of four bolt connecting holes in the flange part is phi 78mm, the size of the holes is 9 x 14 x 8.6mm (8.6 is the depth of 14mm holes), the linear flange bearing 05 mainly functions to provide a track for the linear optical axis 04 to vibrate up and down.

⑥ fixing ring 06. the fixing ring 06 is made of an annular aluminum plate with the thickness of 10mm and the inner diameter and the outer diameter of phi 62mm and phi 190mm respectively.78 mm of the aluminum plate is perforated with four holes with the diameter of phi 9mm for connecting with the linear flange bearing 05. the fixing ring 06 is used for fixing the linear flange bearing 05, the fixing ring 06 is fixed with the base 01 through four supports 09, and the supports 09 are connected with the base 01 and the fixing ring 06 through 38 small-size corner connectors.

⑦ the mounting disc 016 is an aluminum plate with diameter phi 80mm and thickness 10mm, four round holes with size 5.5 x 12 x 5mm (inner hole phi 5.5mm through, outer hole phi 12mm deep 5mm) are processed at diameter phi 32mm for connecting with the straight line optical axis 04, a threaded hole M8 is processed in the middle of the mounting disc 016 for mounting the threaded connecting rod of M8 fixedly connected with the bearing seat 11.

⑧ the total length of the threaded rod is 120mm, the length of the part with M8 threads is 110mm, the head is a cuboid with the length of 10mm, the section is a square with the side length of 4mm, the installation is convenient, the threaded rod is used for fixing the weight, the weight with a hole in the middle is sleeved on the threaded rod, and then the weight can be moved without any trouble by screwing on the weight pressing disc 15-4 (which can be replaced by a bolt).

⑨ bracket 09 the bracket 09 has four brackets 09, which are made of 503mm long stainless steel hollow square tubes with cross-section of 40mm and 10mm long and wide, and 1.5mm thick, the two ends of the bracket 09 are respectively connected with a fixed ring 06 and a base 01, so that the fixed ring 06 is fixed on the base 01, 4 through holes are punched on one of the brackets 09 for installing a chute track 010 to prevent the rotation of the linear optical axis 04.

⑩ A chute track 010, the chute track 010 is SGR10E, the length is 200mm, and the length is enough for the spring 02 to move back and forth to limit the rotation of the linear optical axis 04.

Rolling shaft 011-1 and guide wheel 011-2: consists of a cylindrical rod with the diameter of phi 6mm and the length of 44mm and a small rotating bearing. One end fixed mounting of cylinder pole can be along with spring 02 up-and-down motion on flange 03, and the rolling bearing of the installation of the pole other end just is located the recess of spout track 010, can reciprocate along spout track 010 and roll, has restricted that the skew has just also restricted flange 03 and the rotation of sharp optical axis 04 about the rolling bearing.

The correlation photosensor 012: the sensor is a correlation photoelectric sensor also called a groove-shaped optical coupler, and two pins of the groove respectively transmit and receive an infrared light source. The working voltage is 5V, and the output is a single-path signal output. When the groove is not blocked, the output is low level, and when the emitted light source is blocked and cannot be received, the output signal is high level. Mounted on flangesA T-shaped light screen 015 is arranged, the light screen 015 moves up and down to and fro continuously along with the spring 02 to shield a light source, the vibration frequency of the spring 02 can be determined by measuring an output signal, and an NIUSB-6008 data acquisition card is used for signal acquisition.

The measurement results are displayed by LabVIEW on a computer, and the light shielding plate can generate one pulse every time passing through the equilibrium position, the time from generation of the 1 st pulse to the 9 th pulse is 4 cycles, and the time is divided by 4 to be used as the measured period T. The weighed mass is calculated by formula (1) and can be displayed directly on the interface.

Experimental testing

1.1 test platform

In the field actual measurement, the influence of gravity is counteracted in an air floatation mode, and the weightlessness state is simulated. The working weight of the air floating block is 100kg, and the compressed air pressure is 4 atmospheric pressures. The measuring device needs to be installed in the horizontal direction, and the spring oscillator base is fixed on the base installation frame 1 through bolts and fixed through a clamp.

1.2 test principle

1.2.1 dead weight measurement

The dead weight refers to the mass of a linear optical axis, an air floating block, a bearing support and the like under the no-load condition and can be measured by a standard weight method. Referring to equation (1), assuming that the weight is m when no load is applied₀Spring vibration period of T₀The two relations are as follows:

loading weight M₁After, the period of vibration is T₁The vibration formula is:

from equations (4) and (5), the mass calculation equation can be derived:

1.2.2 spring rate self-calibration

To ensure that the measurements are accurate, a spring rate calibration should be performed prior to each test. From the formula (4), it can be obtained

After dead weight is determined, a no-load spring stiffness coefficient calibration test is required before weighing measurement, and T is recorded₀In order to calculate the spring rate k.

1.2.3 weighing measurement

m₀、T₀After the determination, the measured mass M can be obtained according to equation (8).

1.3 test procedure

1.3.1 dead weight measurement

And selecting a data storage position and selecting a sampling time. The device is pushed away from the balance position by 30-50mm, the handle is released instantly after one second of acquisition is started by clicking, and the acquisition vibration frequency is measured. Measuring the vibration period T under the no-load condition₀(ii) a Then loading 20kg and 40kg standard weights, measuring the vibration period T1, and calculating according to the formula (6) to obtain the self weight m₀. Input device dead weight m on operation interface₀。

1.3.2 weight quality test

The weight is 20-80kg, the weight is measured from small to large at each point with the weight of 20kg, 30kg, 40kg, 50kg, 60kg, 65kg, 70kg, 75kg and 80kg, and the measurement is carried out from large to small, and each point is measured for three times. The left side and the right side of the weight support and the upper part of the weight support can be provided with fixed weights.

4.3.3 measurement of human body Mass

The body mass is measured, three postures of standing, squatting and sitting are respectively measured aiming at 70kg and 55kg of people with different body weights, and the influence of the postures on the measurement result is judged. Aiming at the situation that the change of the human body mass is small when the weight is measured, a small mass of about 0.5kg is added on the basis of measuring the human body mass, and whether the observation device can measure the mass change or not is measured, namely the measurement resolution. Note that: the seat needs to be replaced before the measurement of the human body mass, and the self weight needs to be measured again after the replacement.

1.4 test results

1.4.1 device deadweight measurement

The deadweight of the apparatus was measured using 20kg and 40kg standard weights, and the results are shown in Table 1.

TABLE 1 dead weight measurement data sheet

1.4.2 weight quality test

The mass of the weight of 20-80kg is measured, the average value is taken for each mass measurement for three times, the mass is loaded from small to large, the mass is reduced from large to small, and the experimental results are respectively listed in tables 2 and 3.

TABLE 2 weight measurement results from Small to Large

TABLE 3 weight measurements decreasing from big to small

The results of the weight mass measurements are plotted as shown in fig. 11 and 12. FIG. 11 shows that when the weight is loaded from small to large, the absolute error is between-0.06 kg and 0.361kg, the error is within 0.1kg when the weight is between 20kg and 65kg, the self weight of the device is considered to be about 23kg, and the total weight of the test is 43 kg to 88 kg; errors exceed 0.2kg at 70kg, 75kg and 80kg, i.e. mass measurement accuracy is lower at above 70 kg; the relative error is larger in the range that the weight mass is less than 50kg and more than 70 kg; when the weight is unloaded from big to small in turn, the measurement error is increased compared with the previous measurement error, and the measured value is increased, obviously there is a system error. Fig. 12 shows that the relative error of the measurement, whether it is forward or reverse stroke measurement, is only a point exceeding 0.5%.

Repeatability: as can be seen from the measured mass column and the deviation average column in tables 2 and 3, the deviation of multiple measurements for the same mass point is less than 0.1kg, and the repeatability is good.

Stability: as can be seen from fig. 11, when the measured mass is decreased from large to 65kg or less, the absolute error of the measurement increases by about 0.2kg than when the mass is increased from small to large.

1.4.3 human body quality test experiment

(1) Standing posture measurement

The measurement results are listed in Table 4, the weight of about 55kg, the error of the measurement results reaches 3.085kg, the error is large, meanwhile, the repeatability is also large, and the repeatability error exceeds 1 kg.

Table 4 standing type human body mass measurement data

(2) Squat type measurement result

The human body was in a squatting posture and the measurement results are shown in Table 5. The error measured by the method is greatly reduced compared with that measured by a standing type, but still reaches 1.833kg, and the relative error reaches 3.365%. The repeatability indexes are many, and the deviation value is less than 0.3 kg.

TABLE 5 Squat type human body quality measurement data

(3) Sitting posture measurement

The human body adopts a sitting posture and is contracted into a group as much as possible, and the auxiliary bracket fixes each joint of the human body as much as possible. Table 6 lists the results of the measurements. The repeatability of the posture measurement is further improved, the repeatability deviation is less than 0.2kg, the human body mass measurement result has about 3% of errors, and the errors are all positive and considered as system errors. The self-weight calibration data was suspected of being incorrect, recalibration was performed using 54.475kg human body mass as M1 to yield M0-21.687 kg (previously 22.273kg), and the test was repeated, with the results shown in table 7, with improved data, with an error of less than 0.5 kg.

Table 620 kg weight calibration sitting body mass measurement (m)₀＝22.273kg)

TABLE 7 Sitting body Mass measurement application measurement (m)₀＝21.687kg)

Gesture selection: comparing table 4, table 5 and table 6, it can be seen that the measured mass deviates from the average value greatly when the human body mass is measured in a standing mode, and the repeatability of the squat and sitting measurement is better.

The accuracy is as follows: for the standing type, due to the fact that the gravity center is constantly changed, repeatability is poor, accuracy is not considered, the gravity center is obtained by comparing the table 6 with the table 7, the dead weight of the device obtained by calibrating different qualities has certain influence on measuring accuracy, and the dead weight of the device needs to be determined more accurately.

(4) Resolution and sensitivity testing

In the case of the sit-up posture measurement, a small mass of 0.615kg was added and then the test was conducted to know the measurement resolution of the device, and the results are shown in table 8.

Resolution: the mass is increased by 0.596kg and 0.549kg through two measurements, and the resolution is better than 0.1 kg.

TABLE 8 measurement of human body mass after adding a 0.615kg small mass (wrench)

Sensitivity: after a wrench with the mass of 0.615kg is added, the measured mass is respectively increased by 0.596kg and 0.549kg, and the sensitivity is better.

The fastening ring 06 can also be in the form of a structure as shown in fig. 5: the fixing device comprises a fixing ring 06-1 and four fixing arms 06-2, wherein the four fixing arms 06-2 are distributed at equal intervals along the circumferential direction of the fixing ring 06-1 and are respectively fixedly connected with the fixing ring 06-1. The fixing ring with the structure can reduce the weight of the whole machine and is easy to install.

In order to reduce the cost and improve the universality of the bearing support, the human body support and the weight support can be combined into a whole to form a universal support. Such as: including human support chassis 5, seat flat 6, human support trunk 8, trick support 9 (branch trunk), threaded rod 15-3 and weight pressure disk 15-4, seat flat 6 through seat pole 7 fixed mounting in on the human support chassis 5, the one end fixed mounting of human support trunk 8 be in on the human support chassis 5, trick support 9 (branch trunk) with the connection can be dismantled to human support trunk 8, and human support trunk 8 with trick support 9 (branch trunk) is perpendicular, air supporting block 17 fixed mounting be in the bottom of human support chassis 5. One end of the threaded rod 15-3 is in threaded connection with the human body support trunk 8, and the other end of the threaded rod 15-3 is in threaded connection with the weight pressing plate 15-4.

Claims

1. The mass measuring instrument under the weightlessness state is characterized by comprising a measuring instrument host (100), a bearing support and a base mounting rack (1); the measuring instrument main body (100) is provided with a vibration free end and an installation fixed end; the installation stiff end with base mounting bracket (1) fixed connection, the vibration free end with bearing support swing joint, bearing support with the relative position of vibration free end is followed the vibration direction of vibration free end is fixed unchangeable, bearing support with the relative position of vibration free end is followed the perpendicular to the vibration direction of vibration free end is variable.

2. The mass measurement instrument in weightless condition according to claim 1, wherein the load-bearing support comprises a support backbone, and the vibration free end is provided with a connecting bearing seat (11) and an anti-rotation pin (14); the support trunk passes the hole (13) that floats from top to bottom on connecting bearing frame (11), and seted up on the surface of support trunk along the spout (12) that floats from top to bottom of support trunk axis direction, prevent that the one end of rotating pin (14) passes pinhole on connecting bearing frame (11) and stretch into in the spout (12) that floats from top to bottom, prevent rotating pin (14) with threaded connection between connecting bearing frame (11).

3. The mass measurement instrument in a weightless state according to claim 1 or 2, wherein the measurement instrument main body (100) comprises a base (01), a bracket (09), a fixing ring (06), a spring vibration mechanism, a rotation limiting mechanism and a period calculation mechanism; the two ends of the support (09) are respectively fixedly connected with the base (01) and the fixing ring (06), the bottom of the spring vibration mechanism is fixedly installed on the base (01), the top of the spring vibration mechanism penetrates through the fixing ring (06), the rotation limiting mechanism comprises a fixed limiting part and a movable guiding part, the movable guiding part is fixedly installed on the spring vibration mechanism, and the fixed limiting part is fixedly installed on the support (09); the cycle calculating mechanism comprises a fixed part and a movable part, the fixed part of the cycle calculating mechanism is arranged on the bracket (09), and the movable part of the cycle calculating mechanism is arranged on the spring vibration mechanism.

4. The mass-under-weight-loss condition measuring instrument according to claim 3, wherein the spring vibration mechanism comprises a spring (02), a flange (03), a linear optical axis (04) and a linear flange bearing (05); the bottom of the spring (02) is fixedly arranged on the base (01), the top of the spring (02) is fixedly arranged on the lower bottom surface of the flange (03), and the bottom of the linear optical axis (04) is fixedly arranged on the upper surface of the flange (03); the flange portion of straight line flange bearing (05) with retainer plate (06) pass through bolt fixed connection, the bearing portion of straight line flange bearing (05) is located base (01) with between retainer plate (06), the top of sharp optical axis (04) is passed the shaft hole of straight line flange bearing (05) and towards keeping away from the direction of the bearing portion of straight line flange bearing (05) stretches out, flange (03) with spring (02) are located base (01) with between the bearing portion of straight line flange bearing (05).

5. The mass measuring instrument under weightless condition according to claim 4, wherein the base (01) and the flange (03) are respectively provided with an annular mounting groove (01-1), the outer diameter of the annular mounting groove (01-1) is equal to the outer diameter of the spring (02), the inner diameter of the annular mounting groove (01-1) is equal to the inner diameter of the spring (02), and the bottom end of the spring (02) is fixedly mounted in the annular mounting groove (01-1).

6. The mass measurement instrument in the weightless state according to claim 5, wherein four linear clamping pieces (01-2) crossing the annular mounting groove (01-1) are respectively mounted on the base (01) and the flange (03), and the four linear clamping pieces (01-2) are distributed at equal intervals along the circumferential direction of the annular mounting groove (01-1).

7. The mass measuring instrument in the weightless state according to claim 3, wherein the fixed limiting component is a chute track (010) having a linear chute, the moving guide component comprises a rolling shaft (011-1) and a guide wheel (011-2), one end of the rolling shaft (011-1) is fixedly mounted on the spring vibration mechanism through a shaft cover (014), the guide wheel (011-2) is located in the linear chute of the chute track (010), and the guide wheel (011-2) is mounted on the other end of the rolling shaft (011-1) through a bearing; the sliding groove rail (010) is installed on one side face, facing the spring vibration mechanism, of the support (09), and a linear sliding groove in the sliding groove rail (010) is parallel to the reciprocating direction of the spring vibration mechanism.

8. The mass measurement instrument in a weightless state according to claim 3, wherein the fixed component of the period calculation mechanism is a correlation photoelectric sensor (012), and the moving component of the period calculation mechanism is a light shielding plate (015); one end of the light screen (015) is fixedly arranged on the spring vibration mechanism, and the other end of the light screen (015) reciprocates between the emitting end (07) and the receiving end (08) of the correlation photoelectric sensor (012) along with the movement of the spring vibration mechanism; the support (09) is a linear vertical plate, and the linear vertical plate and the base (01) as well as the linear vertical plate and the fixed ring (06) are fixedly connected through right-angle connecting pieces (013); the number of the linear vertical plates is four, and the linear vertical plates are distributed at equal intervals along the circumferential direction of the spring vibration mechanism; the fixing ring (06) comprises a fixing ring (06-1) and four fixing arms (06-2), wherein the four fixing arms (06-2) are distributed at equal intervals along the circumferential direction of the fixing ring (06-1) and are respectively fixedly connected with the fixing ring (06-1); the stiffness of the spring (02) is: when the total mass m weighed was 90kg, the period of vibration T of the spring was 1.75-2.25 s.

9. The mass measuring instrument in the weightless state according to claim 1 or 2, further comprising an optical platform (2), an air-floating platform (3) and an air-floating block (17), wherein the base mounting frame (1) and the air-floating platform (3) are respectively and fixedly mounted on the upper surface of the optical platform (2), and the air-floating block (17) is fixedly mounted at the bottom of the bearing bracket; the weight support is a weight support (15), the weight support (15) comprises a weight support chassis (15-1), a weight support trunk (15-2), a threaded rod (15-3) and a weight pressure plate (15-4), the bottom end of the weight support trunk (15-2) is fixedly installed on the weight support chassis (15-1), one end of the threaded rod (15-3) is in threaded connection with the weight support trunk (15-2), and the other end of the threaded rod (15-3) is in threaded connection with the weight pressure plate (15-4); the air floating block (17) is fixedly arranged on the lower bottom surface of the weight support chassis (15-1); the threaded rod (15-3) comprises a vertical mounting threaded rod, a first horizontal mounting threaded rod and a second horizontal mounting threaded rod, and the lower end of the vertical mounting threaded rod extends into an axial middle hole in the top end of the weight support trunk (15-2) and is in threaded connection with the weight support trunk (15-2); the first horizontal installation threaded rod and the second horizontal installation threaded rod are parallel to the ground and coaxially located on two sides of the weight support trunk (15-2).

10. The mass measuring instrument in the weightless state according to claim 1 or 2, further comprising an optical platform (2), an air-floating platform (3) and an air-floating block (17), wherein the base mounting frame (1) and the air-floating platform (3) are respectively and fixedly mounted on the upper surface of the optical platform (2), and the air-floating block (17) is fixedly mounted at the bottom of the bearing bracket; the bearing support is a human body support (4), the human body support (4) comprises a human body support chassis (5), a seat flat plate (6), a seat rod (7), a human body support main body (8), a hand and foot support (9) and a chest support (10), the bottom end of the human body support main body (8) and the bottom end of the seat rod (7) are fixedly installed on the upper surface of the human body support chassis (5) respectively, the seat flat plate (6) is fixedly installed at the top end of the seat rod (7), the hand and foot support (9) and the chest support (10) are fixedly installed on the human body support main body (8) respectively, and the air floating block (17) is fixedly installed on the lower bottom surface of the human body support chassis (5); the air floating blocks (17) are composed of a first air floating block, a second air floating block and a third air floating block, and the first air floating block, the second air floating block and the third air floating block are fixedly arranged on the lower bottom surface of the human body support chassis (5) at equal intervals along the same circumference; the hand and foot support (9) consists of an upper hand and foot support, a middle hand and foot support and a lower hand and foot support, the upper hand and foot support is fixedly arranged at the upper end of the human body support main body (8), the lower hand and foot support is fixedly arranged at the lower end of the human body support main body (8), the middle hand and foot support is fixedly arranged on the human body support main body (8) between the upper hand and foot support and the lower hand and foot support, and the chest support (10) is fixedly arranged on the human body support main body (8) between the middle hand and foot support and the lower hand and foot support; the base mounting frame (1) comprises a first longitudinal aluminum section, a second longitudinal aluminum section, a third longitudinal aluminum section, a fourth longitudinal aluminum section, a first transverse aluminum section and a second transverse aluminum section, the first longitudinal aluminum section, the second longitudinal aluminum section, the third longitudinal aluminum section and the fourth longitudinal aluminum section are respectively and fixedly mounted on the upper surface of the optical platform (2), and four side surfaces of the bottom end of the first longitudinal aluminum section, four side surfaces of the bottom end of the second longitudinal aluminum section, four side surfaces of the bottom end of the third longitudinal aluminum section and four side surfaces of the bottom end of the fourth longitudinal aluminum section are respectively and fixedly connected with the optical platform (2) through aluminum section corner pieces; the two ends of the first transverse aluminum section are fixedly connected with the first longitudinal aluminum section and the second longitudinal aluminum section through aluminum section corner pieces respectively, and the two ends of the second transverse aluminum section are fixedly connected with the third longitudinal aluminum section and the fourth longitudinal aluminum section through aluminum section corner pieces respectively; the upper hand and foot support, the middle hand and foot support and the lower hand and foot support penetrate through mounting holes in the human body support trunk (8), and the upper hand and foot support, the middle hand and foot support and the lower hand and foot support are parallel to each other; one end of the chest support (10) penetrates through a mounting hole in the human body support main body (8) and extends towards the position right above the seat flat plate (6), and the chest support (10) is perpendicular to the upper hand and foot support.