Three-dimensional gravity center measuring method of suspension type loading platform system

Abstract

The invention discloses a three-dimensional gravity center measurement method of a suspension type loading platform system, which comprises the following steps of: firstly, measuring and calculating a gravity center projection position of the suspension type loading platform system on a loading platform by adopting an iterative algorithm, then replacing a suspension position, and measuring and calculating the gravity center projection position of the suspension type loading platform system on the loading platform by adopting the iterative algorithm again. And finally, calculating a three-dimensional gravity center position by calculating a three-dimensional straight line intersection point formed by the two lifting points and the gravity center projection. According to the method, the three-dimensional gravity center position of the system can be calculated by simply measuring the gravity center projection twice, and the method is simple and accurate.

Description

Technical Field

[0001] The invention relates to an airdrop loading platform, and in particular to a three-dimensional center of gravity measurement method for a suspended loading platform system. Background Art

[0002] At present, the method for measuring the center of gravity of a suspended loading platform system is to suspend the loading platform in the air through four hanging points, and then measure the center of gravity of the loading platform through the tension of these four hanging points. However, in the general measurement process, the center of gravity of the loading platform is not in the center position, and there is a certain inclination angle when the loading platform is suspended, which results in that this method can only measure the projection position of the center of gravity on the loading platform in the direction of gravity, and cannot measure the true three-dimensional center of gravity position of the entire loading platform. In addition, due to the lack of the center of gravity position in the height direction of the loading platform, the obtained projection position coordinates are not accurate enough as the center of gravity position of the loading platform, and lack practical reference value. Summary of the invention

[0003] In view of the problem of insufficient accuracy of the current center of gravity measurement method for a suspended loading platform system, the purpose of the present invention is to provide a three-dimensional center of gravity measurement method for a suspended loading platform system. The method can calculate the three-dimensional center of gravity position of the system by simply measuring the center of gravity projection twice, which is simple and accurate.

[0004] The technical solution adopted by the present invention is:

[0005] A method for measuring the three-dimensional center of gravity of a suspended loading platform system, firstly using an iterative algorithm to measure the projection position of the center of gravity of the suspended loading platform system on the loading platform, then changing the suspension position, and again using an iterative algorithm to measure the projection position of the center of gravity of the suspended loading platform system on the loading platform, and finally calculating the three-dimensional center of gravity position by calculating the intersection of the three-dimensional straight line formed by two hanging points and the center of gravity projection.

[0006] Assume that the center position of the loading platform is the coordinate origin O(0,0), the center of gravity is O′(x,y), the tension of the four hanging points is G1 to G4, the angles between the four hanging belts and the loading platform are θ1 to θ4, the length of the hanging belt is L, the distance between the hanging points in the X direction is a, and the distance between the hanging points in the Y direction is b, where L is a fixed parameter, and a and b are adjustable parameters;

[0007] Then, the weight of the loading platform is:

[0008] G=G1sinθ1+G2sinθ2+G3sinθ3+G4sinθ4

[0009] By testing the tension of the four hanging points, the center of gravity position is calculated by the moment balance principle, and the center of gravity projection in the x direction is calculated as follows:

[0010]

[0011] That is:

[0012]

[0013] And, calculate the barycentric projection in the Y direction:

[0014]

[0015] That is:

[0016]

[0017] in:

[0018]

[0019] Then, the angle θ between the sling and the loading platform is preliminarily calculated, assuming that x 1 =0,y 1 =0, the included angle θ, at this time θ 1 =θ 2 =θ 3 =θ 4 =θ;

[0020] Then, the center of gravity x is preliminarily calculated 1 ,y 1 ;

[0021] Then, the initially calculated center of gravity x 1 ,y 1 The result is applied to equations (3), (4), (5) and (6) to calculate θ 1 ,θ 2 ,θ 3 and θ 4 ;

[0022] Then, the center of gravity x is calculated in detail for the first time according to equations (1) and (2): 1 ,y 1 ;

[0023] Then, repeat multiple steps and iterate until the result x is calculated. 1 and 1 The absolute value compared with the previous result is much smaller than the maximum error, which is output as the final center of gravity calculation value x 1 ,y 1 ,θ;

[0024] Then, through point G (0, 0, Lcosθ) and projection point 1 (x 1 ,y 1 , 0), calculate the equation of the space line straight line 1:

[0025]

[0026] Then, change the size parameters a and b between the two ropes and recalculate. At this time, G'(0, 0, Lcosθ') and the projection point 2(x 2 ,y 2 , 0), calculate the space line equation 2:

[0027]

[0028] Finally, the intersection of the linear equation 1 and the linear equation 2 is calculated, and the three-dimensional center of gravity (m, n, k) of the suspended loading platform system is obtained.

[0029] The beneficial effects of the present invention are:

[0030] This method uses two simple measurements of the center of gravity projection to calculate the three-dimensional center of gravity position of the system. The overall method only needs to repeat the measurement once. The overall calculation process can be calculated by the software, which is simple and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of center of gravity measurement in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0033] The present embodiment discloses a method for measuring the three-dimensional center of gravity of a suspended loading platform system, the principle of which is: firstly, an iterative algorithm is used to measure the projection position of the center of gravity of the suspended loading platform system on the loading platform, then the suspension position is changed, and an iterative algorithm is used again to measure the projection position of the center of gravity of the suspended loading platform system on the loading platform, and finally, the three-dimensional center of gravity position is calculated by calculating the intersection of the three-dimensional straight line formed by the two hanging points and the center of gravity projection.

[0034] Specifically:

[0035] like Figure 1 As shown, the center position of the loading platform is the coordinate origin O(0, 0), the center of gravity is O′(x, y), the tensions of the four hanging points are G1 to G4, the angles between the four hanging straps and the loading platform are θ1 to θ4, the length of the hanging strap is L, the distance between the hanging points in the X direction is a, and the distance between the hanging points in the Y direction is b, where L is a fixed parameter, and a and b are adjustable parameters;

[0036] Then, the weight of the loading platform is:

[0037] G=G1sinθ1+G2sinθ2+G3sinθ3+G4sinθ4

[0038] By testing the tension of the four hanging points, the center of gravity position is calculated by the moment balance principle, and the center of gravity projection in the X direction is calculated as follows:

[0039]

[0040] That is:

[0041]

[0042] And, calculate the barycentric projection in the Y direction:

[0043]

[0044] That is:

[0045]

[0046] in:

[0047]

[0048] Then, the angle θ between the sling and the loading platform is preliminarily calculated, assuming that x 1 =0,y 1 =0, the included angle θ, at this time θ 1 =θ 2 =θ 3 =θ 4 =θ;

[0049] Then, the center of gravity x is preliminarily calculated 1 ,y 1 ;

[0050] Then, the initially calculated center of gravity x 1 ,y 1 The result is applied to equations (3), (4), (5) and (6) to calculate θ 1 ,θ 2 ,θ 3 and θ 4 ;

[0051] Then, the center of gravity x is calculated in detail for the first time according to equations (1) and (2): 1 ,y 1 ;

[0052] Then, repeat multiple steps and iterate until the result x is calculated. 1 and 1 The absolute value compared with the previous result is much smaller than the maximum error, which is output as the final center of gravity calculation value x 1 ,y 1 ,θ;

[0053] Then, through point G (0, 0, Lcosθ) and projection point 1 (x 1 ,y 1 , 0), calculate the equation of the space line straight line 1:

[0054]

[0055] Then, change the size parameters a and b between the two ropes and recalculate. At this time, G'(0, 0, Lcosθ') and the projection point 2(x 2 ,y 2 , 0), calculate the space line equation 2:

[0056]

[0057] Finally, the intersection of the linear equation 1 and the linear equation 2 is calculated, and the three-dimensional center of gravity (m, n, k) of the suspended loading platform system is obtained.

[0058] This method uses two simple measurements of the center of gravity projection to calculate the three-dimensional center of gravity position of the system. The overall method only needs to repeat the measurement once. The overall calculation process can be calculated by the software, which is simple and accurate.

[0059] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

Claims

1. A method for measuring the three-dimensional center of gravity of a suspended loading platform system, characterized in that: First, an iterative algorithm is used to calculate the projection position of the center of gravity of the suspended loading platform system on the loading platform, then the suspension position is changed, and the iterative algorithm is used again to calculate the projection position of the center of gravity of the suspended loading platform system on the loading platform. Finally, the three-dimensional center of gravity position is calculated by calculating the intersection of the three-dimensional straight line formed by the two hanging points and the center of gravity projection.

2. The three-dimensional center of gravity measurement method of the suspended loading platform system according to claim 1, characterized in that: Assume that the center position of the loading platform is the coordinate origin O(0,0), the center of gravity is O′(x,y), the tension of the four hanging points is G1 to G4, the angles between the four hanging belts and the loading platform are θ1 to θ4, the length of the hanging belt is L, the distance between the hanging points in the X direction is a, and the distance between the hanging points in the Y direction is b, where L is a fixed parameter, and a and b are adjustable parameters; Then, the weight of the loading platform is: G=G1sinθ1+G2sinθ2+G3sinθ3+G4sinθ4 By testing the tension of the four hanging points, the center of gravity position is calculated by the moment balance principle, and the center of gravity projection in the X direction is calculated as follows: That is: And, calculate the barycentric projection in the Y direction: That is: in: Then, the angle θ between the sling and the loading platform is preliminarily calculated. Assuming x1=0, y1=0, the angle θ is obtained. At this time, θ1=θ2=θ3=θ4=θ; Then, the center of gravity x1 and y1 are preliminarily calculated; Then, the initially calculated center of gravity x1 and y1 are used in equations (3), (4), (5), and (6) to calculate θ1, θ2, θ3, and θ4; Then, the center of gravity x1 and y1 are calculated in detail for the first time according to equations (1) and (2); Then, repeat multiple steps and iterate multiple times until the absolute value of the calculated results x1 and y1 compared with the previous results is much smaller than the maximum error, that is, x1, y1, θ are output as the final center of gravity calculation values; Then, through point G (0, 0, Lcosθ) and projection point 1 (x1, y1, 0), calculate the spatial straight line equation 1: Then, change the size parameters a and b between the two ropes and recalculate. At this time, G'(0, 0, Lcosθ') and projection point 2 (x2, y2, 0) are used to calculate the spatial straight line equation 2: Finally, the intersection of the linear equation 1 and the linear equation 2 is calculated, and the three-dimensional center of gravity (m, n, k) of the suspended loading platform system is obtained.

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