CN112644738B - Planet landing obstacle avoidance trajectory constraint function design method - Google Patents

Planet landing obstacle avoidance trajectory constraint function design method Download PDF

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CN112644738B
CN112644738B CN202110069582.9A CN202110069582A CN112644738B CN 112644738 B CN112644738 B CN 112644738B CN 202110069582 A CN202110069582 A CN 202110069582A CN 112644738 B CN112644738 B CN 112644738B
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constraint function
obstacle
landing
track
lander
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CN112644738A (en
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郭延宁
龚有敏
吕跃勇
马广富
李传江
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Harbin Institute of Technology
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/22—Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
    • B64G1/24—Guiding or controlling apparatus, e.g. for attitude control
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/22—Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
    • B64G1/24—Guiding or controlling apparatus, e.g. for attitude control
    • B64G1/244—Spacecraft control systems
    • B64G1/245—Attitude control algorithms for spacecraft attitude control

Abstract

A design method of a planet landing obstacle avoidance trajectory constraint function belongs to the technical field of lander trajectory constraint. The problem of current lander movable range is little, and the conservatism of landing track is strong, is unfavorable for the design of lander guidance law is solved. According to the method, obstacles are equivalent to 3 different space geometric shapes according to the acquired obstacle information on the surface of the planet, and coordinate information of each vertex of the equivalent space geometric shapes is calculated; carrying out segmented design on the landing trajectory function constraint function; when the equivalent space geometry is a cone-shaped terrain or a frustum-shaped terrain, the track constraint function is divided into two sections, when the equivalent space geometry is a step-shaped terrain, the number of the sections of the track constraint function depends on the order of the equivalent step, the terrain of the n steps, and the track constraint function is divided into n +1 sections. The invention is suitable for planet landing obstacle avoidance trajectory constraint.

Description

Planet landing obstacle avoidance trajectory constraint function design method
Technical Field
The invention belongs to the technical field of lander trajectory constraint.
Background
With the vigorous development of aerospace technology, planetary exploration has attracted extensive attention, and has achieved significant achievements in the past decades. The planet landing process usually comprises three stages of atmospheric admission, descent and landing, wherein the landing process determines the landing precision of the whole planet detection, is a key stage for ensuring the safety of the lander, and is always deeply concerned and researched by broad scholars at home and abroad.
In the landing process, as the meteorite crater, the mountain range and other rugged complex terrains exist on the surface of the planet, the lander is easy to collide with obstacles on the surface of the planet in the landing process, and the detection task fails. Therefore, collision with the planetary surface obstacle is a crucial factor directly influencing landing safety, is one of critical technologies that must be solved in the landing process, and has become one of the hot spots of research. In addition, with the continuous deepening of the detection mission, the future detection mission takes more complex terrains such as canyons, meteorite pits and the like as landing points to obtain detection data with more scientific investigation significance, and when the landings are in the terrains, the landers face higher collision risks, and the requirement on the autonomous obstacle avoidance capability of the landers is higher. Therefore, how to design the obstacle avoidance trajectory constraint for the landing process is the key technical problem to be solved.
At present, slope constraint or relaxed slope constraint is mainly adopted to constrain the landing track of the lander. When the landing trajectory of the lander is constrained by adopting slope constraint, the terrain around the landing point is not taken into consideration, and due to the existence of the slope constraint, the movable range of the lander is greatly reduced, so that the conservatism of the landing trajectory of the lander is increased, and the design of the guidance law of the lander is not facilitated.
Disclosure of Invention
The invention aims to solve the problems that an existing lander is small in movable range, strong in conservation of landing tracks and not beneficial to design of a guidance law of the lander, and provides a method for designing a constraint function of a planet landing obstacle avoidance track.
The invention relates to a method for designing a constraint function of a planet landing obstacle avoidance track, which comprises the following steps:
step one, according to the acquired planet surface obstacle information, the obstacle is equivalent to 3 different space geometric shapes; comprises a cone shape, a frustum shape and a step shape;
step two, calculating coordinate information of each vertex of the equivalent space geometric shape;
step three, carrying out segmented design on the land trajectory constraint function according to the equivalent space geometric shape and the coordinate information of each vertex of the geometric shape;
the method specifically comprises the following steps: when the equivalent space geometry is a cone-shaped or frustum-shaped terrain, the trajectory constraint function is divided into two sections, wherein the first section is positioned above the obstacle, and the second section is positioned from the top point of the obstacle to the landing point;
when the equivalent space geometry is step-shaped terrain, the number of sections of the track constraint function depends on the order of equivalent steps and the terrain of n steps, the track constraint function is divided into (n +1) sections, the first section is positioned above the obstacle, the last section is positioned between the step at the lowest edge and the landing point, and the middle (n-1) section is positioned between the steps;
the track constraint functions of the 1 st section to the nth section in the case of the step-shaped terrain are the same as the track constraint functions of the 1 st section in the case of the cone-shaped terrain and the frustum-shaped terrain, and the track constraint function of the j section in the case of the step-shaped terrain is specifically as follows:
Figure GDA0003200000810000021
Figure GDA0003200000810000022
wherein ξijAltitude error, xi, of lander altitude and jth obstacle of equivalent obstacleij＝z-hijJ 1,2, n, i x, y represent two coordinate axes of the landing gear level, i represents the x-direction component or the y-direction component of the landing gear level during landing, n is a positive integer and represents the total number of segments of the track constraint function, wijDistance from the jth obstacle edge to the landing site, hijIs the height of the jth obstacle, and z is the landingHeight of the device, kij1＞0，kij2＞0，kij3＞0，kij1Is the proportionality coefficient, k, of the adaptive parameter of the j-th track constraint function in the i directionij2Is the height error proportional coefficient, k, of the adaptive parameter of the j-th track constraint function in the i directionij3Is the height error proportional coefficient, k, of the j-th track constraint function in the i directionijIs the adaptive parameter of the j-th track constraint function in the i direction,
Figure GDA0003200000810000023
is an adaptive parameter kijDerivative of (p)ij0Is the initial value of the j section of track constraint function in the i direction;
the n +1 th section of track constraint function in the step-shaped terrain is the same as the track constraint function in the 2 nd section of the cone-shaped and frustum-shaped terrain, and the n +1 th section of track constraint function specifically comprises the following steps:
Figure GDA0003200000810000024
Figure GDA0003200000810000025
Figure GDA0003200000810000026
where ρ isi(n+1)The trajectory constraint function of the n +1 th obstacle, k, for the i directioni(n+1)1The more than 0 is the proportionality coefficient of the adaptive parameter of the (n +1) th track constraint function in the i direction, ki(n+1)2The higher error ratio coefficient of the adaptive parameter of the (n +1) th track constraint function in the i direction is more than 0, ki(n+1)3The height error proportionality coefficient of the (n +1) th track constraint function in the i direction is more than 0, z is the height of the lander, and rhoifMaximum landing accuracy allowed for the i direction, zfThe height, rho, of the lander corresponding to the lateral convergence of the lander to the maximum allowable landing accuracyi(n+1)0Is the initial value of the (n +1) th track constraint function in the i direction, xii(n+1)Altitude error of lander altitude from equivalent obstacle segment n + 1.
Further, when j is 1, the initial value ρ of the constraint function of the first stagei10Satisfies the following conditions:
Figure GDA0003200000810000031
where ρ isi10Initial value of the 1 st track constraint function for i direction, z0Is the initial height of the lander, hi1Is the height, ξ, of the 1 st obstaclei10Height error of initial height of lander and 1 st obstacle;
when j is 2,.. n, the constraint function ρ of the j-th stageij0J ═ 2.. n, satisfying:
Figure GDA0003200000810000032
wi(j-1)distance from the (j-1) th obstacle to the center of the landing site in the i direction, hi(j-1)Height of the (j-1) th obstacle; w is aijDistance of j-th obstacle from the center of landing point in i direction, hijHeight of jth obstacle;
further, in the second stage of the conical obstacle and the frustum-shaped obstacle, in order to ensure that the trajectory constraint function is always located outside the obstacle, the trajectory constraint function satisfies that the absolute value of the slope at the connecting point is smaller than the slope of the hypotenuse of the regular geometric shape.
Further, for cone-shaped obstacles and frustum-shaped obstacles, the initial value ρ of the constraint function of stage 2i20And when selecting, the following conditions are satisfied:
Figure GDA0003200000810000033
wherein (i)1，z1) Is the coordinates of the top point of the obstacle, ((ii))i2，z2) Is the coordinates of the apex of the bottom surface of the obstacle,
Figure GDA0003200000810000034
is that
Figure GDA0003200000810000035
The value at the point of connection is,
Figure GDA0003200000810000036
is the derivative of the 2 nd trajectory constraint function.
The invention fully considers the terrain around the selected landing point, and equates the obstacles on the surface of the planet into 3 different regular space geometric shapes; by designing a nonlinear trajectory constraint function, the boundary of a regular space geometric shape equivalent to a barrier can be well fitted, the movable space of the lander in the landing process is improved as much as possible, and the conservatism of the system is reduced; the trajectory constraint function can provide a large movement space when the height of the lander is larger than the height of the obstacle, so that the limitation on the lander is reduced, and the conservatism of the system is reduced.
Drawings
FIG. 1 is a schematic representation of the obstacle and its spatial geometry according to the present invention;
FIG. 2 is a schematic diagram of a conical terrain trajectory constraint function partitioning according to the present invention;
FIG. 3 is a schematic diagram of the partitioning of a frustum-shaped topographic track constraint function designed by the present invention;
FIG. 4 is a schematic diagram of a step-shaped terrain track constraint function partitioning according to the present invention;
FIG. 5 is a schematic diagram of the relationship between cone obstacle information and constraint functions according to the present invention;
FIG. 6 is a schematic diagram of the relationship between the frustum-shaped obstacle information and the constraint function according to the present invention;
FIG. 7 is a schematic diagram of a relationship between stepped obstacle information and a constraint function according to the present invention;
FIG. 8 is a schematic illustration of the slope relationship at the apex of a conical topography according to the present invention;
FIG. 9 is a schematic illustration of the slope relationship at the apex of a prismoid form of the present invention;
FIG. 10 is a graph of the effect of the conical terrain fit of the present invention;
FIG. 11 is a graph of the effect of frustum-shaped terrain fitting according to the invention;
fig. 12 is a graph showing the effect of fitting the stepped topography according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.
The first embodiment is as follows: the following describes the present embodiment with reference to fig. 1 to 4, and the specific method of the present embodiment for designing the planet landing obstacle avoidance trajectory constraint function is as follows:
step one, according to the acquired planet surface obstacle information, the obstacle is equivalent to 3 different space geometric shapes; comprises a cone shape, a frustum shape and a step shape;
step two, calculating coordinate information of each vertex of the equivalent space geometric shape;
step three, carrying out segmented design on the land trajectory constraint function according to the equivalent space geometric shape and the coordinate information of each vertex of the geometric shape;
the method specifically comprises the following steps: when the equivalent space geometry is a cone-shaped or frustum-shaped terrain, the trajectory constraint function is divided into two sections, wherein the first section is positioned above the obstacle, and the second section is positioned from the top point of the obstacle to the landing point;
when the equivalent space geometry is step-shaped terrain, the number of sections of the track constraint function depends on the order of equivalent steps and the terrain of n steps, the track constraint function is divided into (n +1) sections, the first section is positioned above the obstacle, the last section is positioned between the step at the lowest edge and the landing point, and the middle (n-1) section is positioned between the steps;
the track constraint functions of the 1 st section to the nth section in the case of the step-shaped terrain are the same as the track constraint functions of the 1 st section in the case of the cone-shaped terrain and the frustum-shaped terrain, and the track constraint function of the j section in the case of the step-shaped terrain is specifically as follows:
Figure GDA0003200000810000051
Figure GDA0003200000810000052
wherein ξijAltitude error, xi, of lander altitude and jth obstacle of equivalent obstacleij＝z-hijJ 1,2, n, i x, y represent two coordinate axes of the landing gear level, i represents the x-direction component or the y-direction component of the landing gear level during landing, n is a positive integer and represents the total number of segments of the track constraint function, wijDistance from the jth obstacle edge to the landing site, hijIs the height of the jth obstacle, z is the height of the lander, kij1＞0，kij2＞0，kij3＞0，kij1Is the proportionality coefficient, k, of the adaptive parameter of the j-th track constraint function in the i directionij2Is the height error proportional coefficient, k, of the adaptive parameter of the j-th track constraint function in the i directionij3Is the height error proportional coefficient, k, of the j-th track constraint function in the i directionijIs the adaptive parameter of the j-th track constraint function in the i direction,
Figure GDA0003200000810000053
is an adaptive parameter kijDerivative of (p)ij0Is the initial value of the j section of track constraint function in the i direction;
the n +1 th section of track constraint function in the step-shaped terrain is the same as the track constraint function in the 2 nd section of the cone-shaped and frustum-shaped terrain, and the n +1 th section of track constraint function specifically comprises the following steps:
Figure GDA0003200000810000054
Figure GDA0003200000810000055
Figure GDA0003200000810000061
where ρ isi(n+1)The trajectory constraint function of the n +1 th obstacle, k, for the i directioni(n+1)1The more than 0 is the proportionality coefficient of the adaptive parameter of the (n +1) th track constraint function in the i direction, ki(n+1)2The higher error ratio coefficient of the adaptive parameter of the (n +1) th track constraint function in the i direction is more than 0, ki(n+1)3The height error proportionality coefficient of the (n +1) th track constraint function in the i direction is more than 0, z is the height of the lander, and rhoifMaximum landing accuracy allowed for the i direction, zfThe height, rho, of the lander corresponding to the lateral convergence of the lander to the maximum allowable landing accuracyi(n+1)0Is the initial value of the (n +1) th track constraint function in the i direction, xii(n+1)Altitude error of lander altitude from equivalent obstacle segment n + 1.
Track constraint function rho for j section of step-shaped terrainijDerivation function:
Figure GDA0003200000810000062
wherein v iszFor the current speed of the lander in the height direction, the functions of each stage are continuous functions, so that the guidance law cannot be suddenly changed due to the discontinuity of the constraint functions when the guidance law is designed by adopting the track constraint function.
Further, when j is 1, the firstInitial value ρ of a constraint function of a phasei10Satisfies the following conditions:
Figure GDA0003200000810000063
where ρ isi10Initial value of the 1 st track constraint function for i direction, z0Is the initial height of the lander, hi1Is the height, ξ, of the 1 st obstaclei10Height error of initial height of lander and 1 st obstacle;
when j is 2,.. n, the constraint function ρ of the j-th stageij0J ═ 2.. n, satisfying:
Figure GDA0003200000810000064
as shown in FIGS. 5 to 7, wi(j-1)Distance from the (j-1) th obstacle to the center of the landing site in the i direction, hi(j-1)Height of the (j-1) th obstacle; w is aijDistance of j-th obstacle from the center of landing point in i direction, hijHeight of jth obstacle;
the derivation can be:
Figure GDA0003200000810000065
wherein the content of the first and second substances,
Figure GDA0003200000810000071
for the derivative function of the n +1 th section of track constraint function, for the conical obstacle and the frustum-shaped obstacle, in order to ensure that the track constraint function is always positioned outside the obstacle, the track constraint function should satisfy that the absolute value of the slope at the connecting point is smaller than the slope of the hypotenuse of the regular geometric shape, so that the parameters satisfy the following conditions in the process of selecting:
Figure GDA0003200000810000072
wherein (i)1，z1) Is the coordinate of the top point of the obstacle, (i)2，z2) The coordinates of the top of the obstacle bottom surface are shown in fig. 8 to 9.
Figure GDA0003200000810000073
Is that
Figure GDA0003200000810000074
The value at the connecting point is
Figure GDA0003200000810000075
The slope of the tangent at the apex is,
Figure GDA0003200000810000076
is the derivative of the 2 nd trajectory constraint function.
The invention first establishes a spatial geometrical description of the obstacle: according to the photograph of the planetary surface published so far, the obstacles of the planetary surface convexity are equivalent to 3 regular spatial geometries: pyramidal, truncated pyramidal, and stepped, as shown in fig. 1. According to terrain data of the planet surface obtained by a previous detection task or detection information of a proper sensor on the lander, the terrain around the selected landing point can be equivalent according to the three regular space geometries, and then the position information of the equivalent space geometry can be obtained according to the terrain information and used for designing a subsequent track constraint function.
Then, carrying out track constraint function division: and segmenting the track constraint function according to the equivalent space geometry, and for the conical and frustum-shaped terrains, dividing the track constraint function into 2 sections, wherein the first section is positioned above the obstacle, and the second section is from the top point of the obstacle to the landing point. For step-shaped obstacles, the number of sections of the track constraint function depends on the step order of an equivalent step shape, for a terrain with n steps, the track constraint function can be divided into (n +1) sections, the first section is positioned above the obstacle, the bottommost step of the last section is positioned between the landing points, and the rest are positioned between the obstacles. As shown in fig. 2 to 4.
The first segment is located above the obstacle because when the lander moves in this space, there is no risk of collision of the lander regardless of the motion trajectory of the lander, so the segment trajectory constraint function should ensure that the lander has enough motion space in this segment.
The second to nth track constraint functions are positioned between obstacles, and the track constraint functions are fitted to the edges of the obstacles as much as possible so as to better simulate the obstacles, thereby ensuring the movable space of the lander as much as possible and ensuring that the lander cannot collide with the obstacles.
The trajectory constraint function of the (n +1) th segment is located between the last obstacle and the desired landing site, which on the one hand not only requires that the trajectory constraint function fits the obstacle as closely as possible in order to model the obstacle, but on the other hand should also ensure that the lateral movement of the lander has converged to the maximum lateral landing error allowable when the height of the lander is less than a certain height.
initial rho of j-th track constraint function in i directioni10The selection of (A) is divided into two types:
a) parameter selection of 1 st section track constraint function
From the above analysis, it can be seen that paragraph 1 should contain the initial lateral position of the lander. So ρi10Should be selected to satisfy:
Figure GDA0003200000810000081
where z0 is the initial height of the lander, hi1Is the height, ξ, of the 1 st obstaclei10Height error of initial height of lander and 1 st obstacle.
In addition, the 1 st track constraint function should make the lander have enough motion space, so p can be adjustedi10Is selected as the larger value, rhoi10The larger the selection, the larger the space the leg 1 trajectory constraint function can provide for the lander motion.
b) Parameter selection of track constraint functions from section 2 to section n
In order to ensure the continuity of the trajectory constraint function, it should be ensured that the end point of the trajectory constraint function of the previous segment is the start point of the trajectory constraint function of the next segment, and therefore ρij0J 2.. n, which should satisfy:
Figure GDA0003200000810000082
wherein, wi(j-1)Distance from the (j-1) th obstacle to the center of the landing site in the i direction, hi(j-1)Is the height of the (j-1) th obstacle, wijDistance of j-th obstacle from the center of landing point in i direction, hijThe height of the jth obstacle.
(1) Design of (n +1) th section track constraint function
The (n +1) th section of track constraint function not only needs to ensure good fitting barrier, but also needs to ensure the final transverse side towards the land precision, therefore, the (n +1) th section of track constraint function is designed as:
Figure GDA0003200000810000083
Figure GDA0003200000810000084
Figure GDA0003200000810000085
wherein k isi(n+1)1The more than 0 is the proportionality coefficient of the adaptive parameter of the (n +1) th track constraint function in the i direction, ki(n+1)2The higher error ratio coefficient of the adaptive parameter of the (n +1) th track constraint function in the i direction is more than 0, ki(n+1)3The height error proportionality coefficient of the (n +1) th track constraint function in the i direction is more than 0, z is the height of the lander, and rhoifMaximum landing accuracy allowed for the i direction, zfThe corresponding height of the lander when the lateral direction of the lander is converged to the allowable maximum landing precisionAnd (4) degree.
Derived by derivation
Figure GDA0003200000810000091
From the above formula, it can be seen that when z ═ zfTime, rhoi(n+1)＝ρif。
Figure GDA0003200000810000092
Further, in the second stage of the conical obstacle and the frustum-shaped obstacle, in order to ensure that the trajectory constraint function is always located outside the obstacle, the trajectory constraint function satisfies that the absolute value of the slope at the connecting point is smaller than the slope of the hypotenuse of the regular geometric shape.
Further, for cone-shaped obstacles and frustum-shaped obstacles, the initial value ρ of the constraint function of stage 2i20And when selecting, the following conditions are satisfied:
Figure GDA0003200000810000093
wherein (i)1，z1) Is the coordinate of the apex of the obstacle, (i)2，z2) Is the coordinates of the apex of the obstacle bottom surface, as shown in fig. 8 to 9,
Figure GDA0003200000810000094
is that
Figure GDA0003200000810000095
The value at the point of connection is,
Figure GDA0003200000810000096
is the derivative of the 2 nd trajectory constraint function.
In the existing planet landing problem, slope constraint is generally adopted to constrain the trajectory of the lander, on one hand, the slope constraint is adopted to constrain the trajectory of the lander without considering the terrain around the landing point, on the other hand, when the slope constraint is adopted to limit the landing trajectory of the lander, the movable space of the lander is determined by the cone angle of the slope constraint, and when the height of the lander is greater than the height of an obstacle, the movable space of the lander is also greatly limited, so that the conservatism of the system is greatly improved.
The specific embodiment is as follows:
in order to verify that the designed trajectory constraint function can well fit obstacles, the part respectively fits obstacles of different equivalent regular spatial geometrical configurations in 3 by the designed trajectory constraint function to prove the correctness of the designed trajectory constraint function.
(1) Conical topography
The positions of the three vertices of the topographic equivalent cone are (500,0), (1000,0) and (1000 ).
The parameters of the trajectory constraint function are selected as rhoi10＝2000，ki11＝10，ki12＝0.02，ki13＝1，ki21＝2.5，ki22＝0.00005，ki23＝1，zf＝1，ρif＝1。
The results are shown in fig. 10, and it is clear from the graph that the designed track constraint function can be well fitted to the barrier edge, and when the height is reduced to 1m, the transverse direction is converged to the allowed maximum error, and the effectiveness and the correctness of the designed track constraint function on the conical terrain are verified.
(2) Terrace with edge type topography
The positions of the four vertices of the topographic equivalent to a truncated pyramid are (500,0), (1000 ), (2000,1000), and (2500, 0).
The parameters of the trajectory constraint function are selected as rhoi10＝2000，ki11＝10，ki12＝0.02，ki13＝1，ki21＝2.5，ki22＝0.00005，ki23＝1，zf＝1，ρif＝1。
The result is shown in fig. 11, and it is clear from the figure that the designed trajectory constraint function can fit the obstacle edge well, and when the height is reduced to 1m, the lateral direction has converged to the maximum error allowed, and the validity and correctness of the designed trajectory constraint function on the prismoid terrain are verified.
(3) Step-shaped topography
Taking the second step as an example, the positions of the vertices of the topographic equivalent staircase are (500,0), (500 ), (1000,500) and (1000 ).
The parameters of the trajectory constraint function are selected as rhoi10＝2000，ki11＝10，ki12＝0.05，ki13＝1，ki21＝1，ki22＝0.05，ki23＝1，ki31＝1，ki32＝0.0012，ki33＝1，zf＝1，ρif＝1。
The result is shown in fig. 12, and it is clear from the figure that the designed track constraint function can fit the obstacle edge well, and when the height is reduced to 1m, the lateral direction has converged to the maximum error allowed, and the effectiveness and correctness of the designed track constraint function on the step-shaped terrain are verified.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.

Claims (5)

1. A planet landing obstacle avoidance trajectory constraint function design method is characterized by comprising the following specific steps:
step one, according to the acquired planet surface obstacle information, the obstacle is equivalent to 3 different space geometric shapes; comprises a cone shape, a frustum shape and a step shape;
step two, calculating coordinate information of each vertex of the equivalent space geometric shape;
step three, carrying out segmented design on the land trajectory constraint function according to the equivalent space geometric shape and the coordinate information of each vertex of the geometric shape;
the method specifically comprises the following steps: when the equivalent space geometry is a cone-shaped or frustum-shaped terrain, the trajectory constraint function is divided into two sections, wherein the first section is positioned above the obstacle, and the second section is positioned from the top point of the obstacle to the landing point;
when the equivalent space geometry is step-shaped terrain, the number of sections of the track constraint function depends on the order of equivalent steps and the terrain of n steps, the track constraint function is divided into n +1 sections, the first section is positioned above the obstacle, the last section is positioned between the step at the lowest edge and the landing point, and the middle n-1 section is positioned between the steps;
the track constraint functions of the 1 st section to the nth section in the case of the step-shaped terrain are the same as the track constraint functions of the 1 st section in the case of the cone-shaped terrain and the frustum-shaped terrain, and the track constraint function of the j section in the case of the step-shaped terrain is specifically as follows:
Figure FDA0003200000800000011
Figure FDA0003200000800000012
wherein ξijAltitude error, xi, of lander altitude and jth obstacle of equivalent obstacleij＝z-hijJ 1,2, n, i x, y represent two coordinate axes of the landing gear level, i represents the x-direction component or the y-direction component of the landing gear level during landing, n is a positive integer and represents the total number of segments of the track constraint function, wijDistance from the jth obstacle edge to the landing site, hijIs the height of the jth obstacle, z is the height of the lander, kij1＞0，kij2＞0，kij3＞0，kij1Is the j-th track constraint function of the i directionK is the scaling factor of the adaptive parameterij2Is the height error proportional coefficient, k, of the adaptive parameter of the j-th track constraint function in the i directionij3Is the height error proportional coefficient, k, of the j-th track constraint function in the i directionijIs the adaptive parameter of the j-th track constraint function in the i direction,
Figure FDA0003200000800000013
is an adaptive parameter kijDerivative of (p)ij0Is the initial value of the j section of track constraint function in the i direction;
the n +1 th section of track constraint function in the step-shaped terrain is the same as the track constraint function in the 2 nd section of the cone-shaped and frustum-shaped terrain, and the n +1 th section of track constraint function specifically comprises the following steps:
Figure FDA0003200000800000021
Figure FDA0003200000800000022
Figure FDA0003200000800000023
where ρ isi(n+1)Trajectory constraint function, k, for the n +1 th obstacle in the i directioni(n+1)1The more than 0 is the proportionality coefficient of the adaptive parameter of the n +1 th track constraint function in the i direction, ki(n+1)2The more than 0 is the height error proportional coefficient of the adaptive parameter of the n +1 th track constraint function of the i direction, ki(n+1)3The height error proportionality coefficient of the n +1 th track constraint function in the i direction is more than 0, z is the height of the lander, and rhoifMaximum landing accuracy allowed for the i direction, zfThe height, rho, of the lander corresponding to the lateral convergence of the lander to the maximum allowable landing accuracyi(n+1)0Is the initial value of the (n +1) th track constraint function in the i direction, xii(n+1)Altitude error of lander altitude from equivalent obstacle segment n + 1.
2. The method for designing the constraint function of the obstacle avoidance trajectory for the planet landing as claimed in claim 1, wherein when j is 1, the initial value p of the constraint function in the first stage isi10Satisfies the following conditions:
Figure FDA0003200000800000024
where ρ isi10Initial value of the 1 st track constraint function for i direction, z0Is the initial height of the lander, hi1Is the height, ξ, of the 1 st obstaclei10Height error of initial height of lander and 1 st obstacle.
3. The method for designing the constraint function of the planetary landing obstacle avoidance trajectory according to claim 2, wherein when j is 2ij0Satisfies the following conditions:
Figure FDA0003200000800000025
wi(j-1)distance of j-1 st obstacle from the center of landing point in the i direction, hi(j-1)Height of the j-1 st obstacle; w is aijDistance of j-th obstacle from the center of landing point in i direction, hijThe height of the jth obstacle.
4. The method for designing the planet landing obstacle avoidance trajectory constraint function according to claim 2, wherein for the second stage of the conical obstacle and the frustum-shaped obstacle, the trajectory constraint function satisfies that the absolute value of the slope at the connecting point is smaller than the slope of the hypotenuse of the regular geometric shape in order to ensure that the trajectory constraint function is always located outside the obstacle.
5. The method for designing the planet landing obstacle avoidance trajectory constraint function according to claim 4, wherein the initial value p of the constraint function at the 2 nd stage is the initial value p of the cone-shaped obstacle and the frustum-shaped obstaclei20And when selecting, the following conditions are satisfied:
Figure FDA0003200000800000031
wherein (i)1，z1) Is the coordinate of the top point of the obstacle, (i)2，z2) Is the coordinates of the apex of the bottom surface of the obstacle,
Figure FDA0003200000800000032
is that
Figure FDA0003200000800000033
The value at the point of connection is,
Figure FDA0003200000800000034
is the derivative of the 2 nd trajectory constraint function.
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Citations (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001328600A (en) * 2000-05-19 2001-11-27 Fuji Heavy Ind Ltd Landing point searching device, flying object using therewith and landing point evaluating device
CN1851597A (en) * 2006-05-17 2006-10-25 哈尔滨工业大学 Deep space detector soft landing autonomic obstruction evasion control method
CN101762273A (en) * 2010-02-01 2010-06-30 北京理工大学 Autonomous optical navigation method for soft landing for deep space probe
CN102173313A (en) * 2010-12-24 2011-09-07 北京控制工程研究所 Soft landing relay obstacle avoiding method
CN102854880A (en) * 2012-10-08 2013-01-02 中国矿业大学 Robot whole-situation path planning method facing uncertain environment of mixed terrain and region
CN102981507A (en) * 2012-11-29 2013-03-20 北京理工大学 Control method of soft landing autonomic obstacle avoidance fixed-thruster
WO2014003517A1 (en) * 2012-06-29 2014-01-03 인텔렉추얼디스커버리 주식회사 Mobile robot and method for covering and controlling entire online path of mobile robot
CN103662091A (en) * 2013-12-13 2014-03-26 北京控制工程研究所 High-precision safe landing guiding method based on relative navigation
CN103869820A (en) * 2014-03-18 2014-06-18 北京控制工程研究所 Ground navigation planning control method of rover
CN104267734A (en) * 2014-08-01 2015-01-07 北京理工大学 Mars complex terrain region safe landing trajectory generation method with minimum fuel consumption
CN105068427A (en) * 2015-08-31 2015-11-18 哈尔滨工业大学 Finite time robust cooperative tracking control method for multi-robot system
CN105929844A (en) * 2016-04-26 2016-09-07 哈尔滨工业大学 Obstacle avoidance method for soft landing of object outside earth under multi-obstacle constraint environment
CN107340716A (en) * 2017-07-06 2017-11-10 北京理工大学 A kind of planetary landing power dropping geometry protruding rail mark method of guidance
CN109597415A (en) * 2018-12-06 2019-04-09 山东大学 Rover paths planning method and system based on moonscape safe landing area
CN109977455A (en) * 2019-01-30 2019-07-05 广东工业大学 It is a kind of suitable for the ant group optimization path construction method with terrain obstruction three-dimensional space
CN110686683A (en) * 2019-11-01 2020-01-14 北京理工大学 Planetary landing trajectory online optimization method based on uneven expansion ellipsoid
CN111319802A (en) * 2020-03-18 2020-06-23 北京理工大学 Self-adaptive curvature matching guidance method for small celestial body attachment track
CN111752305A (en) * 2020-06-30 2020-10-09 国电南瑞科技股份有限公司 Mountain land type distributed photovoltaic power station unmanned aerial vehicle inspection obstacle avoidance method and system
CN111762341A (en) * 2020-07-06 2020-10-13 北京理工大学 Safe attached multimode switching guidance method for on-line extraction of small celestial body morphology features
CN111761581A (en) * 2020-07-07 2020-10-13 上海木木聚枞机器人科技有限公司 Path planning method and device, and narrow space traveling method and device
CN111924139A (en) * 2020-08-03 2020-11-13 北京理工大学 Small celestial body landing obstacle avoidance constant thrust control method based on expansion early warning area
CN111959825A (en) * 2020-07-24 2020-11-20 南京航空航天大学 Mars star watch low-altitude throwing robot and control method thereof

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1191306B1 (en) * 2000-09-26 2006-11-22 Fuji Photo Film Co., Ltd. Distance information obtaining apparatus and distance information obtaining method
US6512976B1 (en) * 2001-04-27 2003-01-28 Honeywell International Inc. Method and system for terrain aided navigation
FR2943318B1 (en) * 2009-03-17 2011-05-20 Astrium Sas SPATIAL SENSOR INTERLASTING DEVICE AND METHOD OF LANDING A PROBE PROVIDED WITH SUCH A DEVICE
DE102010004571B3 (en) * 2010-01-04 2011-04-28 Astrium Gmbh Loading device for spacecraft
CN103901907B (en) * 2014-03-31 2015-05-27 北京控制工程研究所 Soft landing obstacle avoidance simulation test system
CN106294280B (en) * 2016-08-22 2018-11-20 麻毅威 A kind of trajectory planning method
CN108279011B (en) * 2018-01-30 2021-09-03 北京理工大学 Planet detection landing track comprehensive optimization method
CN109598243B (en) * 2018-12-06 2021-08-24 山东大学 Moon surface safe landing area selection method and system
US11378986B2 (en) * 2019-04-01 2022-07-05 Honeywell International Inc. Systems and methods for landing and takeoff guidance
CN110562493B (en) * 2019-09-06 2021-03-30 北京理工大学 Mars power descending trajectory planning method based on vector trajectory
US20200005656A1 (en) * 2019-09-13 2020-01-02 Intel Corporation Direction finding in autonomous vehicle systems
CN110723315B (en) * 2019-09-23 2021-02-09 北京控制工程研究所 Track generation method for missile-type flight detection of celestial body surface

Patent Citations (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001328600A (en) * 2000-05-19 2001-11-27 Fuji Heavy Ind Ltd Landing point searching device, flying object using therewith and landing point evaluating device
CN1851597A (en) * 2006-05-17 2006-10-25 哈尔滨工业大学 Deep space detector soft landing autonomic obstruction evasion control method
CN101762273A (en) * 2010-02-01 2010-06-30 北京理工大学 Autonomous optical navigation method for soft landing for deep space probe
CN102173313A (en) * 2010-12-24 2011-09-07 北京控制工程研究所 Soft landing relay obstacle avoiding method
WO2014003517A1 (en) * 2012-06-29 2014-01-03 인텔렉추얼디스커버리 주식회사 Mobile robot and method for covering and controlling entire online path of mobile robot
CN102854880A (en) * 2012-10-08 2013-01-02 中国矿业大学 Robot whole-situation path planning method facing uncertain environment of mixed terrain and region
CN102981507A (en) * 2012-11-29 2013-03-20 北京理工大学 Control method of soft landing autonomic obstacle avoidance fixed-thruster
CN103662091A (en) * 2013-12-13 2014-03-26 北京控制工程研究所 High-precision safe landing guiding method based on relative navigation
CN103869820A (en) * 2014-03-18 2014-06-18 北京控制工程研究所 Ground navigation planning control method of rover
CN104267734A (en) * 2014-08-01 2015-01-07 北京理工大学 Mars complex terrain region safe landing trajectory generation method with minimum fuel consumption
CN105068427A (en) * 2015-08-31 2015-11-18 哈尔滨工业大学 Finite time robust cooperative tracking control method for multi-robot system
CN105929844A (en) * 2016-04-26 2016-09-07 哈尔滨工业大学 Obstacle avoidance method for soft landing of object outside earth under multi-obstacle constraint environment
CN107340716A (en) * 2017-07-06 2017-11-10 北京理工大学 A kind of planetary landing power dropping geometry protruding rail mark method of guidance
CN109597415A (en) * 2018-12-06 2019-04-09 山东大学 Rover paths planning method and system based on moonscape safe landing area
CN109977455A (en) * 2019-01-30 2019-07-05 广东工业大学 It is a kind of suitable for the ant group optimization path construction method with terrain obstruction three-dimensional space
CN110686683A (en) * 2019-11-01 2020-01-14 北京理工大学 Planetary landing trajectory online optimization method based on uneven expansion ellipsoid
CN111319802A (en) * 2020-03-18 2020-06-23 北京理工大学 Self-adaptive curvature matching guidance method for small celestial body attachment track
CN111752305A (en) * 2020-06-30 2020-10-09 国电南瑞科技股份有限公司 Mountain land type distributed photovoltaic power station unmanned aerial vehicle inspection obstacle avoidance method and system
CN111762341A (en) * 2020-07-06 2020-10-13 北京理工大学 Safe attached multimode switching guidance method for on-line extraction of small celestial body morphology features
CN111761581A (en) * 2020-07-07 2020-10-13 上海木木聚枞机器人科技有限公司 Path planning method and device, and narrow space traveling method and device
CN111959825A (en) * 2020-07-24 2020-11-20 南京航空航天大学 Mars star watch low-altitude throwing robot and control method thereof
CN111924139A (en) * 2020-08-03 2020-11-13 北京理工大学 Small celestial body landing obstacle avoidance constant thrust control method based on expansion early warning area

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
一种探测器自主安全着陆区确定及精确避障的策略;金涛等;《计算机研究与发展》;20190218;第56卷(第12期);2649-2659 *
嫦娥三号自主避障软着陆控制技术;张洪华等;《中国科学: 技术科学》;20140630;第44卷(第6期);559-568 *
嫦娥三号软着陆轨道优化设计与研究;程望斌等;《湖南理工学院学报(自然科学版)》;20150331;第28卷(第1期);40-44 *
火星科学实验室着陆系统全过程GNC技术分析;郭延宁等;《深 空 探 测 学 报》;20170228;第4卷(第1期);82-88 *

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