CN112441263A

CN112441263A - Passive microgravity simulator

Info

Publication number: CN112441263A
Application number: CN201910805396.XA
Authority: CN
Inventors: 丁宜康; 李亦非; 于锐渤; 胡仁杰; 董振辕
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-08-29
Filing date: 2019-08-29
Publication date: 2021-03-05

Abstract

The invention discloses a novel passive microgravity simulator, which comprises: the device comprises a cylindrical base, a sleeve, a parallelogram connecting rod, a transverse shaft, a spring, a pulley, a steel wire and wearable equipment; the sleeve is arranged on the cylindrical base, is in clearance fit with the cylindrical base and can rotate freely; the parallelogram connecting rods are divided into four groups, two groups are symmetrically arranged on the sleeve, the other two groups are arranged at the front ends of the two groups, and the assembly is completed by a transverse shaft; one end of the spring is fixed on the base, and the other end of the spring is connected with the steel wire; the pulley is fixed on a transverse shaft of the parallelogram connecting rod structure; the steel wire is wound around a specific pulley and then is connected to a specific transverse shaft. The method and the system realize the passive simulation of the microgravity environment more economically, more reliably and safely, and provide a novel gravity counteracting method.

Description

Passive microgravity simulator

Technical Field

The invention relates to a gravity counteracting system, in particular to a passive microgravity simulating system.

Background

The ground microgravity simulation and the gravity offset are a new research field which appears along with the development of the aerospace technology, compared with digital simulation and theoretical analysis, an experimental result obtained through the microgravity simulation has more authenticity and reliability, and compared with the traditional gravity offset modes such as airplane weightlessness, liquid suspension, wind tunnel and the like, the passive gravity offset realized by utilizing the combined motion between the mechanical structures has the advantages of low cost, high reliability, long duration and the like. Therefore, the ground microgravity simulation has important significance for ensuring the on-orbit reliable operation of the spacecraft and the task training of the astronauts on the ground.

Disclosure of Invention

The invention provides a passive microgravity simulator for multidimensional movement of human body load, which solves the problems that the existing system is high in cost and cannot well and reliably realize gravity offset for a long time, can stand at a microgravity environment simulation angle, and can complete the task of gravity offset more safely and reliably.

In order to achieve the above object, the present invention provides a passive microgravity simulator for human body load, the system comprising: cylinder base, sleeve, parallelogram connecting rod, cross axle, spring, pulley, steel wire and wearable equipment.

The sleeve is arranged on the cylindrical base, is in clearance fit with the cylindrical base and can rotate freely; the parallelogram connecting rods are divided into four groups, two groups are symmetrically arranged on the sleeve, the other two groups are arranged at the front ends of the two groups, and the assembly is completed by a transverse shaft; one end of the spring is fixed on the base, and the other end of the spring is connected with the steel wire; the pulley is fixed on a transverse shaft of the parallelogram connecting rod structure; the steel wire is wound around a specific pulley and then is connected on a specific transverse shaft;

when the gravity compensation state is achieved, the spring and the steel wire are kept tensioned to provide constant gravity compensation;

when the spring is in a non-gravity-counteracting state, the spring is in contact connection with the steel wire so as to prevent the spring from failing after being tensioned for a long time.

Preferably, the passive microgravity simulator is characterized in that: the sleeve is arranged on a cylindrical boss of the cylindrical base and can rotate around the base by 360 degrees.

Preferably, the passive microgravity simulator is characterized in that: four groups of parallelogram connecting rods are assembled into an extensible structure through a transverse shaft and can freely move in space.

The passive microgravity simulator for the human body, provided by the invention, solves the problems that the existing system is high in cost and cannot realize gravity offset well and reliably for a long time, and has the following advantages:

(1) in order to realize passive counteraction of gravity, the method solves the problem of zero-length springs theoretically through the combination of a parallel four-bar linkage mechanism, a steel wire pulley winding and springs, designs a human body and mechanism follow-up mechanism, realizes that the counteraction of the gravity borne by the human body does not change along with the change of the position and the posture of the human body, and improves the reliability of the microgravity simulation device;

(2) after the method is designed and produced, an MPU6050 six-axis acceleration sensor is used for carrying out data acquisition on the force compensation effect, and data which are in line with theoretical analysis are obtained, so that the aim of constant force compensation can be well fulfilled;

(3) the system is supported by the cylindrical base, and the stability of the whole structure is well guaranteed when a human body moves through the steel disc welded below the cylindrical base, and the weight of the cylindrical base can play a role of balance weight;

(4) the spring is connected to the cylindrical base through the bolt, and due to the fact that the bolt is tensioned under the working state, pretightening force is provided for the bolt, accidents caused by loosening of the bolt are avoided, and safety of a human body is greatly improved.

Drawings

Fig. 1 is a schematic structural view of a passive microgravity simulator for a human body according to the present invention.

FIG. 2 is a schematic view of a parallel four-bar linkage of the present invention.

Fig. 3 is a schematic diagram of the principle of the present invention.

Fig. 4 is a top view of fig. 1.

Fig. 5 is a side view of fig. 1.

Detailed Description

The technical solution of the present invention is further described below with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.

The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

The embodiment provides a passive microgravity simulation device for a human body, as shown in fig. 1, which is a schematic structural diagram of the passive microgravity simulation device for a human body, the system comprises a cylindrical base 1, a boss at the upper end of the cylindrical base 1 is sleeved with a sleeve 2, the sleeve 2 is connected with a parallelogram connecting rod 3, the parallelogram 3 is combined through a cross shaft,

pulleys

4, 5, 6, 7 and 8 are sleeved at fixed positions on the cross shaft,

steel wires

9 and 10 are wound on the

pulleys

4, 5, 6, 7 and 8, two ends of the steel wire 9 are respectively connected with a spring 11 and the cylindrical base 1, and wearable equipment is fixed at the free end of the parallelogram 3.

The microgravity simulator in the embodiment is passive, and the human body gravity fixed in the wearable equipment is completely or partially offset by combining the steel wire pulley windings and utilizing the principle of conservation of potential energy through the spring, so that the effect of simulating microgravity or small gravity environment is realized.

Further, as shown in fig. 2, the parallel four-bar linkage 1 is a split joint type four-bar linkage mechanism, which can move within a certain range along with the movement of the human body, and provides a mounting surface for wearable equipment and human body loads.

Further, the length of the steel wire 9 is equal to the length obtained by subtracting the original length of the spring from the distance between the fixed node of the spring and the base and the pulley 4; the length of the steel wire rope 10 is equal to the sum of the distance from the fixed node of the spring and the base to the pulley 5, the distance from the pulley 5 to the pulley 6, the distance from the pulley 6 to the pulley 7, the distance from the pulley 7 to the pulley 8, the distance from the pulley 7 to the fixed node of the wearable device and the parallelogram connecting rod structure, and the original length of the spring is subtracted.

Fig. 3 is a schematic diagram of a passive microgravity simulator, wherein the dotted lines are springs, m1 and m2 represent the total mass of the rods, each rod is a homogeneous rod, and the parameters are as shown in the figure. It can be seen that the sum of the gravitational potential energy of the whole mechanism and the elastic potential energy of the spring is a constant value VT ═ VMG + VBG + VS ═ C. Wherein VMG is the gravitational potential energy of the whole mechanism, VBG is the gravitational potential energy of the tester fixedly connected on the mechanism, VS is the elastic potential energy of two springs, and C is a certain constant. Since the purpose of this mechanism is to cancel all or part of the gravity of the human body, a proportionality coefficient ρ of the canceled gravity is added to the gravitational potential energy of the human body, and VT is VMG + ρ VBG + VS. According to the parameter adjustment of the mechanism, rho can be changed, and the human body can feel different degrees of gravity counteraction. Expanding the above equation, the total potential energy can be expressed as a function of two angles θ 1 and θ 2, where VT is VMG + ρ VBG + VS is C0+ C1 cos θ 1+ C2C os θ 2. Wherein: c0 (2 × h1+ h2) × (m1+ m2) × g + (h1-h2) ρ × m × g + (1/2) k1 (d 1+ l1^2) + (1/2) k2 (d2^2+ l2^2), C1 m 1^ l1^ g + l1^ (2 m2 g + ρ m g-1 ^ d1), C2 ═ m 2^ l2 g + l2 (ρ mg-k 2^ d 2). The microgravity simulator aims to offset the constant gravity of a human body, and in the formula, the proportion rho of the offset gravity is always constant regardless of the change of the values of theta 1 and theta 2. Since the values of θ 1 and θ 2 are arbitrary, that is, the values of cos θ 1 and cos θ 2 are arbitrary, and C1 and C2 are 0 in order to make the sum VT of the above equations constant, two boundary conditions can be designed to satisfy the requirement of offsetting the constant gravity under the condition that some parameters are known. It is obvious that the weight of each individual is different, and since the gravity that can be counteracted by the mechanism is constant under the condition that other parameters are determined, the proportionality coefficient ρ corresponding to different human bodies is different, and the corresponding body feeling is different. The spring constants k1, k2 and the spring mounting positions d1, d2 can be selected according to the above derived formula so that the same gravity counteracting ratio can be experienced by people of different weights.

In summary, the passive microgravity simulation device provided in this embodiment can achieve constant total or partial gravity cancellation.

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by those skilled in the art that the scope of the invention herein disclosed is not limited to the particular combination of features described above, but also encompasses other arrangements formed by any combination of the above features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. A passive microgravity simulator, the system comprising: the device comprises a cylindrical base, a sleeve, a parallelogram connecting rod, a transverse shaft, a spring, a pulley, a steel wire and wearable equipment;

2. The passive microgravity simulator of claim 1, wherein: the sleeve is arranged on a cylindrical boss of the cylindrical base and can rotate around the base by 360 degrees.

3. The passive microgravity simulator of claim 1, wherein: four groups of parallelogram connecting rods are assembled into an extensible structure through a transverse shaft and can freely move in space.