CN103868648B - The centroid measurement method of three axle air supporting emulation experiment platforms - Google Patents

Abstract

The centroid measurement method of three axle air supporting emulation experiment platforms, belongs to physics emulation field, and the present invention is for solving existing measurement air supporting platform barycenter technology Problems existing. The inventive method comprises the following steps: step one, employing Two-axis obliquity sensor are measured, obtained X-axis angular velocity omega_xWith Y-axis angular velocity omega_y; Adopt angular aceeleration sensor to measure, obtain Z axis angular rate ��_z; Step 2, the kinematics equation listing three axle air supporting emulation experiment platforms: step 3, the kinetic equation listing three axle air supporting emulation experiment platforms: step 4, three formula to kinetic equation described in step 3 carry out integration respectively in time t0, t1 and t2, and with the kinematics solving simultaneous equation of step 2, obtain the centroid position (r of three axle air supporting emulation experiment platforms_x, r_y, r_z).

Description

The centroid measurement method of three axle air supporting emulation experiment platforms

Technical field

The present invention relates to the centroid measurement method of three axle air supporting emulation experiment platforms, belong to physics emulation field.

Background technology

Along with people are to the exploration of the outer space, the satellite of development are placed in air supporting emulation platform and carry out emulation test, reduce research cost with this, it is to increase the success ratio that satellite is executed the task, become the necessary step developed and launch an artificial satellite. Three axle emulation experiment platforms are mainly used in the equipment such as simulated flight device attitude motion under certain circumstances. The development of control techniques and computer technology, and the development and usage of type material so that three axle air supporting emulation experiment platform by volume diminish, rigidity strengthens, and supporting capacity is higher. In addition the progress of science and technology also makes the control accuracy of three axle air supporting emulation experiment platforms and position money precision all be greatly improved. Therefore, three axle air supporting emulation experiment platforms will no longer be only limitted to the experimental simulation of space vehicle, is also applicable to other various directions gradually, such as simulated training during navigation and some high precision, and the emulation test of the experimental installation of high cost before coming into operation.

In three axle air supporting emulation experiment platforms, worktable is the body of air supporting platform, and it is used for the test component of Installation posture Controlling System. Due to satellite when spaceflight must driving moment very little, so when carrying out ground simulation test, it is necessary to disturbance torque to be controlled to very little numerical value. After every disturbance torque controls to specified value, worktable just can float on ball bearing and reach, in any attitude angle, balance of changing and register permanent residence along with the head of the household when this person moves to a new locality, stablize to realize, now satellite is just as floating on spaceflight track, again by remote measurement, telemanipulator, posture control system just can carry out various testing in simulation table. The artificial leveling of tradition is wasted time and energy, and does not often reach good regulating effect. By this levelling gear, rotation center is overlapped with overall barycenter, the worktable developed has very high balance quality, to meet the service requirements of ground simulation experiment.

Chinese patent " measuring method at a kind of 3 d pose angle and system ", its publication number is CN102135421A, publication date is on October 12nd, 2011, the patent proposes the hot spot formed on the image sensor through hole diaphragm by analyzing two path parallel beams, solve the scheme of the movable information of platform three-dimensional space. When but said apparatus does not consider emulation experiment experimental situation may not ideal enoughization, such as dust, cable etc. to light block and machinery platform body vibrations drive light concussion, all can affect the accuracy of measurement.

Chinese patent " a kind of center mass measuring device being applicable to fiber optic gyro recording geometry ", its publication number is CN201138270, and publication date is on January 14th, 2009, the speed of this patent for measuring in gyro sensitive axes. But fiber optic gyro belongs to electronic gyroscope, without rotating element, it is subject to electromagnetic interference, it may also be useful to occasion is restricted. Its drift is very big, in actual applications, if for navigating accurately, guide, it is necessary to carry out very complicated resolving and compensating.

Chinese patent " a kind of the centroid adjustment device with single electronic horizon instrument ", its publication number is CN101900627A, publication date is on September 14th, 2011, although this patent can directly obtain the attitude angle information on a plane and X, Y plane, but its method have employed the rising of driven by motor quality block when regulating Z-direction, until electronic horizon instrument exports non-zero signal, namely three-axis air-bearing table table top is in criticality. This kind of more difficult judgement of criticality, it is necessary to abundant engineering experience, last deviation is relatively big, and is difficult to solve barycenter particular location in Z-direction mediation process.

Summary of the invention

The present invention seeks to solve existing measurement air supporting platform barycenter technology Problems existing, it provides a kind of centroid measurement method of three axle air supporting emulation experiment platforms.

The centroid measurement method of three axle air supporting emulation experiment platforms of the present invention, the method comprises the following steps:

Step one, employing Two-axis obliquity sensor measure X-axis angle information and the Y-axis angle information of three axle air supporting emulation experiment platforms, and then obtain X-axis angular velocity omega_xWith Y-axis angular velocity omega_y;

The angular aceeleration of the Z axle rotation angle of three axle air supporting emulation experiment platforms measured by employing angular aceeleration sensor, and then obtains Z axis angular rate ��_z;

Step 2, the X-axis angular velocity omega obtained according to step one_x, Y-axis angular velocity omega_yWith Z axis angular rate ��_zList the kinematics equation of three axle air supporting emulation experiment platforms:

$\left[\begin{array}{c}\stackrel{\·}{\mathrm{\φ}}\\ \stackrel{\·}{\mathrm{\θ}}\\ \stackrel{\·}{\mathrm{\ψ}}\end{array}\right]={\left(\cos \right)}^{-1}\·\left[\begin{array}{ccc}\cos \mathrm{\θ}& \sin \mathrm{\θ}\sin \mathrm{\φ}& \sin \mathrm{\θ}\cos \mathrm{\φ}\\ 0& \cos \mathrm{\φ}\cos \mathrm{\θ}& -\cos \mathrm{\θ}\sin \mathrm{\φ}\\ 0& \sin \mathrm{\φ}& \cos \mathrm{\φ}\end{array}\right]\·\left[\begin{array}{c}{\mathrm{\ω}}_x\\ {\mathrm{\ω}}_y\\ {\mathrm{\ω}}_z\end{array}\right]$

Wherein, �� is roll angle,For the differential of roll angle; �� is the angle of pitch,For the differential of the angle of pitch; �� is yawing angle,For the differential of yawing angle;

Step 3, the X-axis angular velocity omega that step one is obtained_x, Y-axis angular velocity omega_yWith Z axis angular rate ��_zDifferential, list the kinetic equation of three axle air supporting emulation experiment platforms:

$\left[\begin{array}{c}{\stackrel{\·}{\mathrm{\ω}}}_x\\ {\stackrel{\·}{\mathrm{\ω}}}_y\\ {\stackrel{\·}{\mathrm{\ω}}}_z\end{array}\right]=\left[\begin{array}{c}\frac{(I_y-I_z)\·{\mathrm{\ω}}_y\·{\mathrm{\ω}}_z+mg\·(-cos\mathrm{\φ}\·cos\mathrm{\θ}\·r_y+sin\mathrm{\φ}\·cos\mathrm{\θ}\·r_z)}{I_x}\\ \frac{(I_z-I_x)\·{\mathrm{\ω}}_x\·{\mathrm{\ω}}_z+mg\·(\cos \mathrm{\φ}\·cos\mathrm{\θ}\·r_x+sin\mathrm{\θ}\·r_z)}{I_y}\\ \frac{(I_x-I_y)\·{\mathrm{\ω}}_x\·{\mathrm{\ω}}_y+mg\·(-sin\mathrm{\φ}\·cos\mathrm{\θ}\·r_x-sin\mathrm{\θ}\·r_y)}{I_z}\end{array}\right]$

Wherein: I_xRepresent the rotational inertia of X-axis, I_yRepresent the rotational inertia of Y-axis, I_zRepresent the rotational inertia of Z axle;

M represents three axle air supporting emulation experiment platform and simulation component total masses;

G is universal gravity constant;

(r_x, r_y, r_z) represent the centroid position of three axle air supporting emulation experiment platforms;

Step 4, three formula to kinetic equation described in step 3 carry out integration respectively in time t0, t1 and t2, and with the kinematics solving simultaneous equation of step 2, obtain the centroid position (r of three axle air supporting emulation experiment platforms_x, r_y, r_z):

$\left[\begin{array}{c}{r}_x\\ r_y\\ r_z\end{array}\right]=\frac{1}{mg}\·\left[\begin{array}{c}-I_y\·\underset{t0}{\∫}cos\mathrm{\φ}cos\mathrm{\θ}\·\underset{t1}{\∫}+I_z\·\underset{t0}{\∫}sin\mathrm{\φ}cos\mathrm{\θ}\·\underset{t2}{\∫}{\mathrm{\ω}}_z\\ I_x\·\underset{t1}{\∫}cos\mathrm{\φ}cos\mathrm{\θ}\·\underset{t0}{\∫}{\mathrm{\ω}}_x+I_z\·\underset{t1}{\∫}sin\mathrm{\θ}\·\underset{t2}{\∫}{\mathrm{\ω}}_z\\ -I_x\·\underset{t2}{\∫}\sin \mathrm{\φ}cos\mathrm{\θ}\·\underset{t0}{\∫}{\mathrm{\ω}}_x-I_z\·\underset{t2}{\∫}sin\mathrm{\θ}\·\underset{t2}{\∫}{\mathrm{\ω}}_z\end{array}\right].$

The advantage of the present invention: the centroid measurement method regulation scheme of three axle air supporting emulation experiment platforms of the present invention is comparatively convenient is affected by environment less and have higher measuring accuracy.

Accompanying drawing explanation

Fig. 1 is the control functional block diagram of the centroid measurement method of three axle air supporting emulation experiment platforms of the present invention;

Fig. 2 is the schema of the centroid measurement method of three axle air supporting emulation experiment platforms of the present invention.

Embodiment

Embodiment one: present embodiment is described below in conjunction with Fig. 1 and Fig. 2, the centroid measurement method of three axle air supporting emulation experiment platforms described in present embodiment, the method comprises the following steps:

Step one, employing Two-axis obliquity sensor measure X-axis angle information and the Y-axis angle information of three axle air supporting emulation experiment platforms, and then obtain X-axis angular velocity omega_xWith Y-axis angular velocity omega_y;

The angular aceeleration of the Z axle rotation angle of three axle air supporting emulation experiment platforms measured by employing angular aceeleration sensor, and then obtains Z axis angular rate ��_z;

Step 2, the X-axis angular velocity omega obtained according to step one_x, Y-axis angular velocity omega_yWith Z axis angular rate ��_zList the kinematics equation of three axle air supporting emulation experiment platforms:

$\left[\begin{array}{c}\stackrel{\·}{\mathrm{\φ}}\\ \stackrel{\·}{\mathrm{\θ}}\\ \stackrel{\·}{\mathrm{\ψ}}\end{array}\right]={\left(\cos \right)}^{-1}\·\left[\begin{array}{ccc}\cos \mathrm{\θ}& \sin \mathrm{\θ}\sin \mathrm{\φ}& \sin \mathrm{\θ}\cos \mathrm{\φ}\\ 0& \cos \mathrm{\φ}\cos \mathrm{\θ}& -\cos \mathrm{\θ}\sin \mathrm{\φ}\\ 0& \sin \mathrm{\φ}& \cos \mathrm{\φ}\end{array}\right]\·\left[\begin{array}{c}{\mathrm{\ω}}_x\\ {\mathrm{\ω}}_y\\ {\mathrm{\ω}}_z\end{array}\right]$

Wherein, �� is roll angle,For the differential of roll angle; �� is the angle of pitch,For the differential of the angle of pitch; �� is yawing angle,For the differential of yawing angle;

Step 3, the X-axis angular velocity omega that step one is obtained_x, Y-axis angular velocity omega_yWith Z axis angular rate ��_zDifferential, list the kinetic equation of three axle air supporting emulation experiment platforms:

$\left[\begin{array}{c}{\stackrel{\·}{\mathrm{\ω}}}_x\\ {\stackrel{\·}{\mathrm{\ω}}}_y\\ {\stackrel{\·}{\mathrm{\ω}}}_z\end{array}\right]=\left[\begin{array}{c}\frac{(I_y-I_z)\·{\mathrm{\ω}}_y\·{\mathrm{\ω}}_z+mg\·(-cos\mathrm{\φ}\·cos\mathrm{\θ}\·r_y+sin\mathrm{\φ}\·cos\mathrm{\θ}\·r_z)}{I_x}\\ \frac{(I_z-I_x)\·{\mathrm{\ω}}_x\·{\mathrm{\ω}}_z+mg\·(\cos \mathrm{\φ}\·cos\mathrm{\θ}\·r_x+sin\mathrm{\θ}\·r_z)}{I_y}\\ \frac{(I_x-I_y)\·{\mathrm{\ω}}_x\·{\mathrm{\ω}}_y+mg\·(-sin\mathrm{\φ}\·cos\mathrm{\θ}\·r_x-sin\mathrm{\θ}\·r_y)}{I_z}\end{array}\right]$

Wherein: I_xRepresent the rotational inertia of X-axis, I_yRepresent the rotational inertia of Y-axis, I_zRepresent the rotational inertia of Z axle;

M represents three axle air supporting emulation experiment platform and simulation component total masses;

G is universal gravity constant;

(r_x, r_y, r_z) represent the centroid position of three axle air supporting emulation experiment platforms;

Step 4, three formula to kinetic equation described in step 3 carry out integration respectively in time t0, t1 and t2, and with the kinematics solving simultaneous equation of step 2, obtain the centroid position (r of three axle air supporting emulation experiment platforms_x, r_y, r_z):

The control functional block diagram that the method relates to as shown in Figure 1,

Double-shaft tilt angle sensor adopts gyrostat to realize. Angular aceeleration sensor adopts electric slope angle instrument to realize.

When three axle air supporting emulation experiment platform barycenter do not overlap with air-floating ball bearing rotation center, the carrier table on air-floating ball bearing can present the kinestate of a kind of periodic vibration. Can regard that body coordinate system is moved relative to the fixed point rotary of reference frame as during this three axles air supporting emulation experiment Platform movement. According to theorem of Euler, take initial point as rotation center, around Z axle rotary yaw angle ��, then around Y-axis rotary luffing angle ��, finally, it is that turning axle rotates roll angle �� taking X-axis. Now these three Eulerian angles ��, ��, �� just can determine any one attitude that in body coordinate system, platform rotates.

Three Eulerian angles ��, ��, �� are middle variable,Represent the differential of Eulerian angles, i.e. the circular frequency of three Eulerian angles. I_x, I_y, I_zFor known quantity, just determine when three axle air supporting emulation experiment platforms make.

In step 4, three of kinetic equation described in step 3 formula being carried out in time t0, t1 and t2 integration respectively, this method both can ensure that equation was set up, and can solve again the situation that in the process of resolving, Euler's angular moment battle array is irreversible. The vertical platform kinematics formula of connection and dynamics formula, by centroid position (r_x, r_y, r_z) as unknown quantity, the three axle air supporting current centroid positions of emulation experiment platform counter can be solved.

Embodiment two: present embodiment is described below in conjunction with Fig. 1, enforcement mode one is described further by present embodiment, obtains X-axis angular velocity omega in step one_xWith Y-axis angular velocity omega_yAcquisition process be:

Two-axis obliquity sensor measures X-axis angle information and the Y-axis angle information of three axle air supporting emulation experiment platforms, described X-axis angle information exports to industrial computer through serial communication interface circuit, X-axis angle information is carried out differential process by industrial computer, obtains X-axis angular velocity omega_x;

Described Y-axis angle information exports to industrial computer through RS485 interface circuit, and Y-axis angle information is carried out differential process by industrial computer, obtains Y-axis angular velocity omega_y��

Serial communication interface circuit adopts RS485 or RS232 serial interface circuit.

Embodiment three: present embodiment is described below in conjunction with Fig. 1, enforcement mode one is described further by present embodiment, Z axis angular rate �� in step one_zAcquisition process:

The angular aceeleration of the Z axle rotation angle of three axle air supporting emulation experiment platforms measured by angular aceeleration sensor, the angular aceeleration of described Z axle rotation angle changes, by A/D, the angular aceeleration that circuit conversion becomes numerary signal, the angular aceeleration of described numerary signal is carried out integrated by industrial computer, obtains Z axis angular rate ��_z��

Embodiment four: enforcement mode one is described further by present embodiment, t0=8ms��12ms; T1=16ms��25ms; T2=25ms��35ms.

Embodiment five: enforcement mode one is described further by present embodiment, t0=10ms; T1=20ms; T2=30ms.

Claims (6)

1. the centroid measurement method of three axle air supporting emulation experiment platforms, it is characterised in that, the method comprises the following steps:

Step one, employing Two-axis obliquity sensor measure X-axis angle information and the Y-axis angle information of three axle air supporting emulation experiment platforms, and then obtain X-axis angular velocity omega_xWith Y-axis angular velocity omega_y;

The angular aceeleration of the Z axle rotation angle of three axle air supporting emulation experiment platforms measured by employing angular aceeleration sensor, and then obtains Z axis angular rate ��_z;

Step 2, the X-axis angular velocity omega obtained according to step one_x, Y-axis angular velocity omega_yWith Z axis angular rate ��_zList the kinematics equation of three axle air supporting emulation experiment platforms:

$\left[\begin{array}{c}\stackrel{\·}{\mathrm{\φ}}\\ \stackrel{\·}{\mathrm{\θ}}\\ \stackrel{\·}{\mathrm{\ψ}}\end{array}\right]={\left(cos\right)}^{-1}\·\left[\begin{array}{ccc}cos\mathrm{\θ}& sin\mathrm{\θ}sin\mathrm{\φ}& sin\mathrm{\θ}cos\mathrm{\φ}\\ 0& cos\mathrm{\φ}\cos \mathrm{\θ}& -cos\mathrm{\θ}sin\mathrm{\φ}\\ 0& \sin \mathrm{\φ}& \cos \mathrm{\φ}\end{array}\right]\·\left[\begin{array}{c}{\mathrm{\ω}}_x\\ {\mathrm{\ω}}_y\\ {\mathrm{\ω}}_z\end{array}\right]$

Wherein, �� is roll angle,For the differential of roll angle; �� is the angle of pitch,For the differential of the angle of pitch; �� is yawing angle,For the differential of yawing angle;

Step 3, the X-axis angular velocity omega that step one is obtained_x, Y-axis angular velocity omega_yWith Z axis angular rate ��_zDifferential, list the kinetic equation of three axle air supporting emulation experiment platforms:

$\left[\begin{array}{c}{\stackrel{\·}{\mathrm{\ω}}}_x\\ {\stackrel{\·}{\mathrm{\ω}}}_y\\ {\stackrel{\·}{\mathrm{\ω}}}_z\end{array}\right]=\left[\begin{array}{c}\frac{(I_y-I_z)\·{\mathrm{\ω}}_y\·{\mathrm{\ω}}_z+mg\·(-cos\mathrm{\φ}\·cos\mathrm{\θ}\·r_y+sin\mathrm{\φ}\·cos\mathrm{\θ}\·r_z)}{I_x}\\ \frac{(I_z-I_x)\·{\mathrm{\ω}}_x\·{\mathrm{\ω}}_z+mg\·(\cos \mathrm{\φ}\·cos\mathrm{\θ}\·r_x+sin\mathrm{\θ}\·r_z)}{I_y}\\ \frac{(I_x-I_y)\·{\mathrm{\ω}}_x\·{\mathrm{\ω}}_y+mg\·(-sin\mathrm{\φ}\·cos\mathrm{\θ}\·r_x-sin\mathrm{\θ}\·r_y)}{I_z}\end{array}\right]$

Wherein: I_xRepresent the rotational inertia of X-axis, I_yRepresent the rotational inertia of Y-axis, I_zRepresent the rotational inertia of Z axle;

M represents three axle air supporting emulation experiment platform and simulation component total masses;

G is universal gravity constant;

(r_x, r_y, r_z) represent the centroid position of three axle air supporting emulation experiment platforms;

Step 4, three formula to kinetic equation described in step 3 carry out integration respectively in time t0, t1 and t2, and with the kinematics solving simultaneous equation of step 2, obtain the centroid position (r of three axle air supporting emulation experiment platforms_x, r_y, r_z):

$\left[\begin{array}{c}{r}_x\\ r_y\\ r_z\end{array}\right]=\frac{1}{mg}\·\left[\begin{array}{c}-I_y\·\underset{t0}{\∫}\cos \mathrm{\φ}\cos \mathrm{\θ}\·\underset{t1}{\∫}{\mathrm{\ω}}_y+I_z\·\underset{t0}{\∫}\sin \mathrm{\φ}\cos \mathrm{\θ}\·\underset{t2}{\∫}{\mathrm{\ω}}_z\\ I_x\·\underset{t1}{\∫}\cos \mathrm{\φ}\cos \mathrm{\θ}\·\underset{t0}{\∫}{\mathrm{\ω}}_x+I_z\·\underset{t1}{\∫}\sin \mathrm{\θ}\·\underset{t2}{\∫}{\mathrm{\ω}}_z\\ -I_x\·\underset{t2}{\∫}\sin \mathrm{\φ}\cos \mathrm{\θ}\·\underset{t0}{\∫}{\mathrm{\ω}}_x-I_y\·\underset{t2}{\∫}\sin \mathrm{\θ}\·\underset{t2}{\∫}{\mathrm{\ω}}_z\end{array}\right].$

2. the centroid measurement method of three axle air supporting emulation experiment platforms according to claim 1, it is characterised in that, step one obtains X-axis angular velocity omega_xWith Y-axis angular velocity omega_yAcquisition process be:

Two-axis obliquity sensor measures X-axis angle information and the Y-axis angle information of three axle air supporting emulation experiment platforms, described X-axis angle information exports to industrial computer through serial communication interface circuit, X-axis angle information is carried out differential process by industrial computer, obtains X-axis angular velocity omega_x;

Described Y-axis angle information exports to industrial computer through RS485 interface circuit, and Y-axis angle information is carried out differential process by industrial computer, obtains Y-axis angular velocity omega_y��

3. the centroid measurement method of three axle air supporting emulation experiment platforms according to claim 2, it is characterised in that, serial communication interface circuit adopts RS485 or RS232 serial interface circuit.

4. the centroid measurement method of three axle air supporting emulation experiment platforms according to claim 1, it is characterised in that, Z axis angular rate �� in step one_zAcquisition process:

The angular aceeleration of the Z axle rotation angle of three axle air supporting emulation experiment platforms measured by angular aceeleration sensor, the angular aceeleration of described Z axle rotation angle changes, by A/D, the angular aceeleration that circuit conversion becomes numerary signal, the angular aceeleration of described numerary signal is carried out integrated by industrial computer, obtains Z axis angular rate ��_z��

5. the centroid measurement method of three axle air supporting emulation experiment platforms according to claim 1, it is characterised in that, t0=8ms��12ms; T1=16ms��25ms; T2=25ms��35ms.

6. the centroid measurement method of three axle air supporting emulation experiment platforms according to claim 1, it is characterised in that, t0=10ms; T1=20ms; T2=30ms.