Underwater wall-climbing robot positioning method and positioning device thereof

Abstract

The application discloses a kind of underwater wall-climbing robot positioning method and its positioning device, device includes track, gyro wheel, gyro wheel support and multiple pull line type displacement encoders.Track is fixedly installed in the upper portion of wall-climbing robot, multiple gyro wheels are installed on gyro wheel support to form a whole, can freely roll on track.Multiple displacement encoders are installed on wall surface, the pull line of displacement encoder is connected with the pull line fixed hole on gyro wheel support, to monitor the distance between wall surface fixed point and the pull line fixed hole on gyro wheel support.When wall-climbing robot executes task, the pull line of displacement encoder is changed, simultaneously drive gyro wheel to roll, gyro wheel support is automatically adjusted position in circular track to reduce the possibility that multiple pull lines are intertwined, again combined with coordinate transformation relationship can develop a kind of real-time monitoring underwater wall-climbing robot position method.The method has the advantages of simple structure, low cost compared with underwater acoustic positioning and visual positioning, not subject to water environment interference.

Description

TECHNICAL FIELD

[0001] The present application relates to the underwater wall-climbing robot technical field, especially to a positioning method and positioning device of underwater wall-climbing robot. BACKGROUND

[0002] The precise positioning of underwater wall-climbing robot is the information guarantee and technical prerequisite for reliable and accurate execution of underwater tasks, and is also the difficulty of underwater robot control.

[0003] The existing underwater robot positioning methods are mainly underwater acoustic positioning and visual positioning. The underwater acoustic positioning system is a relatively effective underwater positioning method, but it has a complex structure and expensive equipment. As for visual positioning, although the visual positioning system in the land environment is relatively mature, the visual positioning system in the underwater environment is limited by factors such as water turbidity, and does not achieve the expected effect. SUMMARY

[0004] The present application aims to provide a positioning method of underwater wall-climbing robot, which realizes low cost while ensuring the accuracy of underwater wall-climbing robot positioning. And the positioning device thereof is provided.

[0005] Technical scheme: A positioning method of underwater wall-climbing robot,

[0006] When the robot needs to be positioned on a three-dimensional curved surface, the following steps are included:

[0007] Step one: a circular track is arranged on the robot, a plurality of rollers are arranged on the track, the rollers are installed on the track through a roller support, six wire fixing holes are arranged on the roller support, and the six wire fixing holes are respectively a, b, c, d, e and f;

[0008] Step two: the center of the track is denoted as O, the successive lines of the six wire fixing holes form a circle, the radius of the circle is R, the included angles of the lines formed by the adjacent wire fixing holes and the center O of the track are respectively alpha, beta, phi, gamma and theta, and the six wire fixing holes are connected with six known points A, B, C, D, E and F on the ship wall surface through a wire displacement encoder to monitor the distance between the corresponding wire fixing hole and the fixed point on the ship wall surface in real time;

[0009] Step three: the real-time position of the robot is the projection of the center O of the track on the ship surface, that is, the intersection point P of the straight line perpendicular to the track surface and the ship surface;

[0010] Step four: considering that the geometric configuration of the ship surface is determined, the position coordinates of the ship surface satisfy the known equation in the overall coordinate system: ​

[0011] f(x,y,z) = 0;

[0012] Translate the overall coordinate system oxyz to the position of the orbit center O(x O ,y O ,z O ), and establish a local coordinate system Ox'y'z' in the orbit plane.

[0013] Step five: According to the coordinate transformation relationship, the position coordinates of any point Q in space in the overall coordinate system oxyz (x, y, z) and in the local coordinate system Ox'y'z' (x', y', z') satisfy the following relationship:

[0014]

[0015] Where a ij = cos(e′ j ,e i ) is the direction cosine of the unit vector in the local coordinate system in the overall coordinate system;

[0016] Step six: Let e1, e2, e3 be the unit vectors along the three coordinate axes in the overall coordinate system oxyz, and e'1, e'2, e'3 be the unit vectors along the three coordinate axes in the local coordinate system Ox'y'z'. Then the position coordinates of the orbit center O (x O ,y O ,z O ) and the direction cosines of the unit vectors in the local coordinate system in the overall coordinate system a ij constitute 12 undetermined unknowns; Among them, the unit vectors in the overall coordinate system and the unit vectors in the local coordinate system satisfy the following relationship:

[0017] e′ i = a ji e j ;

[0018] The unit vectors in the rectangular coordinate system satisfy the following relationship:

[0019]

[0020]

[0021] From this, 6 independent equations can be established:

[0022]

[0023] Step seven: Without loss of generality, assume that the wire fixing hole a is just on the x' axis of the local coordinate system Ox'y'z', the position coordinate of the wire fixing hole a in the local coordinate system is (R, 0, 0), and the position coordinate of the wire fixing hole a in the global coordinate system is:

[0024]

[0025] The distance between the wire fixing hole a and the corresponding ship wall fixed point A can be monitored by the displacement encoder as l aA Thus, the following equation is established:

[0026]

[0027] Since the angle between the line Ob connecting the wire fixing hole b and the center O and the line Oa connecting the wire fixing hole a and the center O is α, the position coordinate of the wire fixing hole b in the local coordinate system Ox'y'z' is (Rcosα, Rsinα, 0), and the position coordinate of the wire fixing hole b in the global coordinate system is:

[0028]

[0029] The distance between the wire fixing hole b and the corresponding ship wall fixed point B can be monitored by the displacement encoder as l bB Thus, the following equation is established:

[0030]

[0031] Similarly, four independent equations can be established for the other four wire fixing holes, and thus twelve independent equations are established to determine the twelve unknown position parameters x O , y O , z O , a ij (i, j = 1, 2, 3).

[0032] Step eight: According to the intersection point P of the center O of the circular track along the straight line perpendicular to the track surface and the ship surface, the size of OP can be considered as a known quantity, which is assumed to be s. Since point P is located on the negative half of the Oz' axis of the local coordinate system, the position coordinate of point P in the local coordinate system is (0, 0, -s). According to the transformation relationship between the global coordinate and the local coordinate, the position coordinate of point P in the global coordinate system is:

[0033]

[0034] The position coordinate should also satisfy the known equation of the ship surface coordinate:

[0035] f(x, y, z) = 0;

[0036] Therefore, the position parameter s = s0 is determined, and thus the position coordinates of the underwater robot at position P are:

[0037]

[0038] Furthermore, when the robot needs to perform positioning on a two-dimensional plane, the following steps are included:

[0039] Step 1: Change the three-dimensional coordinate system to a two-dimensional coordinate system oxy, and reduce the number of guy wire fixing holes from six to three, namely a, b, and c. These holes are connected to three known points A, B, and C on the ship's wall through displacement encoders to monitor the distance between the corresponding guy wire fixing holes and the wall fixing points in real time. The relative angles between adjacent guy wire fixing holes are reduced to three, namely α, β, and φ.

[0040] Step 2: Translate the global coordinate system oxy to the center of the orbit circle O(x) O ,y O The position of ) is established in a local coordinate system Ox′y′ on the orbital plane. The plane in which it is located is parallel to the two-dimensional plane of the ship's wall, with a distance of h, which can be regarded as a known quantity;

[0041] Step 3: According to the coordinate transformation relationship, the position coordinates of any point Q in space satisfy the following relationship between the position coordinates (x, y) in the global coordinate system oxy and the position coordinates (x′, y′) in the local coordinate system Ox′y′:

[0042]

[0043] Among them, a ij =cos(e′) j ,e i () is the direction cosine of the unit vector in the local coordinate system in the global coordinate system;

[0044] Step 4: Let e1 and e2 be unit vectors along the two coordinate axes in the global coordinate system oxy, and e′1 and e′2 be unit vectors along the two coordinate axes in the local coordinate system Ox′y′. Then, the position coordinates of the center O of the orbit (x...) O ,y O The direction cosine α of the unit vector in the local coordinate system in the global coordinate system. ij This constitutes 6 unknowns to be determined;

[0045] The unit vector in the global coordinate system and the unit vector in the local coordinate system satisfy the following relationship:

[0046] e′ i =a ji e j ;

[0047] The unit vector in the rectangular coordinate system satisfies the following relationship:

[0048]

[0049]

[0050] Thus, three independent equations can be established:

[0051]

[0052] Step 5: Without loss of generality, assume that the guy wire fixing hole a is exactly on the x' axis of the local coordinate system Ox'y', and the position coordinates of the guy wire fixing hole a in the local coordinate system are (R, 0), and the position coordinates in the global coordinate system are:

[0053]

[0054] The distance between the guy wire fixing hole a and the corresponding fixed point A can be monitored by the displacement encoder, which is l aA , thus the following equation is established:

[0055]

[0056] Since the angle between the line Ob connecting the guy wire fixing hole b and the center O and the line Oa connecting the guy wire fixing hole a and the center O is α, the position coordinates of the guy wire fixing hole b in the local coordinate system Ox'y' are (Rcosα, Rsinα), and the position coordinates in the global coordinate system are:

[0057]

[0058] The distance between the guy wire fixing hole b and the corresponding fixed point B can be monitored by the displacement encoder, which is l bB , thus the following equation is established:

[0059]

[0060] Similarly, similar equations can be established for the guy wire fixing hole c. Thus, six independent equations are established to determine the six unknown position parameters x O , y O , a ij (i, j = 1, 2);

[0061] Step 6: The intersection point P of the circular track center O and the vertical line perpendicular to the track surface on the ship surface in the local coordinate system has position coordinates (x O , y O , therefore, the position coordinates of the position P of the underwater robot are:

[0062]

[0063] Further, when the wall surface of the ship or the marine structure is a plane, a two-dimensional plane positioning method of establishing a two-dimensional coordinate is used for positioning.

[0064] Optimally, the polygon formed by the six known points A, B, C, D, E and F on the ship in sequence is the smallest polygon covering the robot task range. In order to improve the monitoring accuracy, the six displacement encoder arrangement points A, B, C, D, E and F on the wall surface of the ship or the marine structure can be arranged according to the task range optimization, so that the polygon formed by the six points in sequence is the smallest polygon covering the task range.

[0065] A positioning device using the above-mentioned underwater wall-climbing robot positioning method, comprising a track, a plurality of rollers, a roller support, a pull wire fixing hole, and a pull wire type displacement encoder, the track is a circular ring, the plurality of rollers are arranged on the roller support in a circumferential direction and are respectively connected with the roller support through a roller shaft, the roller support is installed in cooperation with the track to enable the rollers to roll on the track, six pull wire fixing holes are arranged on the roller support in a circumferential direction, and six pull wire type displacement encoders are installed on the six arrangement points on the wall surface of the ship or the marine structure, and the pull wire of each pull wire type displacement encoder is connected with a corresponding pull wire fixing hole.

[0066] Further, the device is installed on the robot, and the rollers are driven to roll on the track by the robot. When the robot performs a task, the pull wires of the displacement encoders are changed, and the rollers are driven to roll on the track to automatically adjust the relative position between the roller support and the robot, thereby preventing the pull wires of the displacement encoders from being entangled with each other to a certain extent.

[0067] Optimally, the track is installed on the upper part of the robot. The track is installed on the upper part of the robot to ensure that the center of the track has sufficient height, thereby preventing the pull wires of the displacement encoders from interfering with the wall surface of the ship or the marine structure.

[0068] The displacement encoder is a pull wire type displacement encoder, and the pull wire type displacement encoder should have sufficient range according to the need of performing a task.

[0069] Advantages: Compared with the prior art, the advantages of the present application are that the pull wire type displacement encoder is set to establish a three-dimensional model or a two-dimensional model to realize effective positioning of the robot, and the positioning method has the advantages of simple structure and low cost compared with water sound positioning, and is not easily affected by the water environment compared with visual positioning. BRIEF DESCRIPTION OF DRAWINGS

[0070] Figure 1 It is a structural schematic view of the track.

[0071] Figure 2Structure diagram of the roller and the roller support;

[0072] Figure 3 Structure diagram of the positioning device;

[0073] Figure 4 Positioning principle diagram of the robot on a three-dimensional curved surface;

[0074] Figure 5 Positioning principle diagram of the robot on a two-dimensional curved surface. DETAILED DESCRIPTION

[0075] The present application will be further illustrated below in conjunction with the drawings and specific embodiments, and it should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application.

[0076] An underwater wall-climbing robot positioning method, wherein the positioning method of the underwater robot on a three-dimensional curved surface comprises the following steps:

[0077] Step one: as shown in the drawings, a circular track is arranged on the robot, and a plurality of rollers are arranged on the track to roll thereon, as shown in the drawings, Figure 1 Figure 2 , 3 The rollers are all mounted on roller supports, the roller supports are matched with the track, six wire fixing holes are arranged on the roller supports, and the six wire fixing holes are respectively a, b, c, d, e, and f.

[0078] Step two: as shown in the drawings, the track center is denoted as O, the six wire fixing holes form a circle with a radius R, the included angles of the lines formed by the adjacent wire fixing holes and the track center O are respectively α, β, φ, Figure 4 γ, and θ, and the six wire fixing holes are connected with six known points A, B, C, D, E, and F on the ship surface through wire displacement encoders to monitor the distances between the corresponding wire fixing holes and the fixed points on the ship surface in real time. Step three: considering that the underwater robot may turn, U-turn, and other operations when cleaning the outer surface of the ship, the above mechanism arrangement can avoid the mutual entanglement of the wire displacement encoders of the underwater robot when turning to a certain extent. In order to enable the underwater cleaning robot to perform specific tasks, the position of the underwater robot needs to be predicted in real time. This position can be considered as the projection of the above track center O on the ship surface, that is, the intersection P of the straight line passing through the center of the circular track and perpendicular to the track surface and the ship surface.

[0079] Step four: since the geometric configuration of the ship surface is determined, it is assumed that the position coordinates of the ship surface satisfy the known equation in the overall coordinate system:

[0080]

[0081] ​​f(x, y, z) = 0;

[0082] Translate the overall coordinate system oxyz to the position of the orbit center O(x O ,y O ,z O ), and establish a local coordinate system Ox'y'z' in the orbit plane.

[0083] Step five: According to the coordinate transformation relationship, the position coordinates of any point Q in space in the overall coordinate system oxyz (x, y, z) and in the local coordinate system Ox'y'z' (x', y', z') satisfy the following relationship:

[0084]

[0085] Where a ij = cos(e′ j ,e i ) is the direction cosine of the unit vector in the local coordinate system in the overall coordinate system;

[0086] Step six: Let e1, e2, e3 be the unit vectors along the three coordinate axes in the overall coordinate system oxyz, and e'1, e'2, e'3 be the unit vectors along the three coordinate axes in the local coordinate system Ox'y'z'. The position coordinates (x O ,y O ,z O ) of the orbit center O and the direction cosines a ij of the unit vectors in the local coordinate system in the overall coordinate system constitute 12 undetermined unknowns. Among them, the unit vectors in the overall coordinate system and the unit vectors in the local coordinate system satisfy the following relationship:

[0087] e′ i = a ji e j ;

[0088] The unit vectors in the rectangular coordinate system satisfy the following relationship:

[0089]

[0090]

[0091] From this, six independent equation systems can be established:

[0092]

[0093] Step seven: Without loss of generality, assume that the guy wire fixing hole a is exactly on the x' axis of the local coordinate system Ox'y'z', and the guy wire fixing hole a is at the position (R, 0, 0) in the local coordinate system, and its position coordinates in the overall coordinate system are:

[0094]

[0095] The distance between the pull line fixing hole a and the corresponding fixed point A can be monitored by the displacement encoder as l aA Thus, the following equation is established:

[0096]

[0097] Since the angle between the line Ob connecting the pull line fixing hole b and the center O and the line Oa connecting the pull line fixing hole a and the center O is α, the position coordinates of the pull line fixing hole b in the local coordinate system Ox'y'z' are (Rcosα, Rsinα, 0), and the position coordinates in the global coordinate system are:

[0098]

[0099] The distance between the pull line fixing hole b and the corresponding fixed point B can be monitored by the displacement encoder as l bB Thus, the following equation is established:

[0100]

[0101] Similarly, four independent equations can be established for the other four pull line fixing holes. Thus, twelve independent equations are established to determine twelve unknown position parameters x O , y O , z O , a ij (i, j = 1, 2, 3).

[0102] Step eight: According to the intersection point P of the center O of the circular track along the line perpendicular to the track surface and the ship surface, the size of OP can be regarded as a known quantity, which is assumed to be s. Since point P is located on the negative half of the Oz' axis of the local coordinate system, the position coordinates of point P in the local coordinate system are (0, 0, -s). According to the transformation relationship between the global coordinates and the local coordinates, the position coordinates of point P in the global coordinate system are:

[0103]

[0104] The position coordinates should satisfy the known equation of the ship surface coordinates:

[0105] f(x, y, z) = 0;

[0106] Thus, the position parameter s = s0 is determined, and finally, the position coordinates of the position P of the underwater robot are:

[0107]

[0108] The positioning method of the underwater robot on a two-dimensional plane comprises the following steps:

[0109] First step: when the ship surface is relatively flat, which can be regarded as a two-dimensional plane, only three pull line fixing holes are needed to realize the positioning of the underwater robot due to the reduction of the dimension. As shown in the figure, an overall coordinate system oxy is established on the two-dimensional plane, and three pull line fixing holes a, b and c are respectively connected with three points A, B and C on the ship surface whose positions are known through displacement encoders to monitor the distance between the corresponding rollers and the fixing points in real time, and the relative angles between the adjacent rollers are α, β and φ respectively. Figure 5

[0110] Second step: the overall coordinate system oxy is moved to the position of the track center O(x O ,y O ), and a local coordinate system Ox′y′ is established on the track plane. The plane where the track is located is parallel to the two-dimensional plane of the ship surface, and the distance h can be regarded as a known quantity. According to the coordinate transformation relationship, the position coordinates (x, y) of any point Q in space in the overall coordinate system oxy and the position coordinates (x′, y′) in the local coordinate system Ox′y′ satisfy the following relationship:

[0111]

[0112] Wherein, a ij =cos(e′ j ,e i ) is the direction cosine of the unit vector in the local coordinate system in the overall coordinate system.

[0113] Third step: e1 and e2 are the unit vectors along the two coordinate axes in the overall coordinate system oxy, and e′1 and e′2 are the unit vectors along the two coordinate axes in the local coordinate system Ox′y′. The position coordinates (x O ,y O ) of the track center O and the direction cosines a ij of the unit vectors in the local coordinate system in the overall coordinate system constitute six undetermined unknowns.

[0114] The unit vectors in the overall coordinate system and the unit vectors in the local coordinate system satisfy the following relationship:

[0115] e′ i = a ji e j ;

[0116] The unit vectors in the rectangular coordinate system satisfy the following relationship:

[0117]

[0118] ​

[0119] Thus, three independent equations can be established:

[0120]

[0121] Step 4: Without loss of generality, assume that the guy fixing hole a is exactly on the x' axis of the local coordinate system Ox'y', and the position coordinates of the guy fixing hole a in the local coordinate system are (R, 0), and the position coordinates of the guy fixing hole a in the global coordinate system are:

[0122]

[0123] The distance between the guy fixing hole a and the corresponding fixed point A can be monitored by the displacement encoder, which is l aA Thus, the following equation is established:

[0124]

[0125] Since the angle between the line Ob connecting the guy fixing hole b and the center O and the line Oa connecting the guy fixing hole a and the center O is α, the position coordinates of the guy fixing hole b in the local coordinate system Ox'y' are (Rcosα, Rsinα), and the position coordinates of the guy fixing hole b in the global coordinate system are:

[0126] x b = x O + a 11 Rcosα + a 12 Rsinα

[0127] y b = y O + a 21 Rcosα + a 22 Rsinα

[0128] z b = h

[0129] The distance between the guy fixing hole b and the corresponding fixed point B can be monitored by the displacement encoder, which is l bB Thus, the following equation is established:

[0130]

[0131] Similarly, similar equations can be established for the guy fixing hole c. Thus, six independent equations are established to determine six unknown position parameters x O , y O , a ij (i, j = 1, 2).

[0132] Fifth step: the position coordinates of the intersection P between the straight line perpendicular to the track plane and the ship surface along the center O of the circular track in the local coordinate system are (x O ,y O ), and finally, the position coordinates of the position P of the underwater robot are:

[0133]

[0134] The positioning device using the above-mentioned underwater wall-climbing robot positioning method comprises a track 1, a roller 2, a roller support 3, a pull line fixing hole 4, and a displacement encoder 5. The displacement encoder 5 is a pull line type displacement encoder. The track 1 is a circular ring, the track 1 is provided with the roller support 3, a plurality of rollers 2 are orderly arranged on the roller support 3, the combination of the roller 2 and the roller support 3 can smoothly roll in the track 1, a plurality of pull line fixing holes 4 are arranged on the roller support 3, the displacement encoder 5 is fixed on a selected point of the wall surface, the pull line of the displacement encoder 5 is connected to the corresponding pull line fixing hole 4 of the roller support 3, so as to monitor the distance between the pull line fixing hole 4 and the selected point of the wall surface, and the position of the underwater wall-climbing robot can be predicted through the above-mentioned algorithm.

[0135] The device is installed on the robot, and the roller is driven to roll on the track by the robot. The track is installed on the upper part of the robot.

Claims

1. A positioning method for an underwater wall-climbing robot, characterized in that: When a robot needs to be positioned on a three-dimensional curved surface, the following steps are included: Step 1: Set up a circular track on the robot, with multiple rollers that roll on the track. The rollers are mounted on the track using roller brackets, and six wire fixing holes are set on the roller brackets, namely a, b, c, d, e, and f. Step Two: Mark the center of the track as O. The lines connecting the six guy wire fixing holes form a circle with radius R. The angles between the lines connecting adjacent guy wire fixing holes and the track center O are α, β, and φ, respectively. The six wire fixing holes γ and θ are respectively connected to six known points A, B, C, D, E, and F on the ship's wall via wire-type displacement encoders to monitor the distance between the corresponding wire fixing holes and the fixed points on the ship's wall in real time. Step 3: Let the robot's real-time position be the projection of the center O of the track onto the ship's surface, which is the intersection point P of the center of the track along a straight line perpendicular to the track surface and the ship's surface. Step 4: Considering that the geometry of the ship's surface is fixed, assume that the position coordinates of the ship's surface satisfy the known equations in the global coordinate system: f(x,y,z)=0; Translate the global coordinate system oxyz to the center of the orbit O(x) O ,y O ,z O At the position of ), establish a local coordinate system Ox′y′z′ in the orbital plane; Step 5: According to the coordinate transformation relationship, the position coordinates of any point Q in space satisfy the following relationship between the position coordinates (x, y, z) in the global coordinate system oxyz and the position coordinates (x′, y′, z′) in the local coordinate system Ox′y′z′: Among them, a ij =cos(e′) j ,e i () is the direction cosine of the unit vector in the local coordinate system in the global coordinate system; Step Six: Let e1, e2, and e3 be unit vectors along the three coordinate axes in the global coordinate system oxyz, and e1′, e2′, and e3′ be unit vectors along the three coordinate axes in the local coordinate system Ox′y′z′. Then, find the position coordinates (x, y, z) of the center O of the orbit. O ,y O ,z O The direction cosine α of the unit vector in the local coordinate system in the global coordinate system. ij This results in 12 unknowns to be determined; among them, the unit vector in the global coordinate system and the unit vector in the local coordinate system satisfy the following relationship: And i ′=a ji And j ; The unit vector in a rectangular coordinate system satisfies the following relationship: This allows us to establish six independent equations: Step 7: Without loss of generality, suppose the wire fixing hole a is exactly on the x′ axis of the local coordinate system Ox′y′z′, and the position coordinates of the wire fixing hole a in the local coordinate system are (R,0,0). Its position coordinates in the global coordinate system are: The distance l between the guy wire fixing hole a and the corresponding ship wall fixing point A can be monitored by the displacement encoder. aA Therefore, the following equation is established: Since the angle between the line Ob connecting the wire fixing hole b to the center O and the line Oa connecting the wire fixing hole a to the center O is α, the coordinates of the wire fixing hole b in the local coordinate system Ox′y′z′ are (Rcosα,Rsinα,0), and its position coordinates in the global coordinate system are: The distance l between the guy wire fixing hole b and the corresponding ship wall fixing point B can be monitored using a displacement encoder. bB Therefore, the following equation is established: Similarly, four independent equations can be established for the other four guy wire fixing holes, thus establishing 12 independent equations to determine 12 unknown position parameters x. O y O z O a ij (i,j=1,2,3); Step 8: Let point P be the intersection of the center O of the circular track and the ship's surface along a straight line perpendicular to the track plane. The magnitude of OP can be considered a known quantity, let's assume it's s. Since point P lies on the negative half-axis of the local coordinate system Oz′, the position coordinates of point P in the local coordinate system are (0, 0, -s). According to the transformation relationship between global and local coordinates, the position coordinates of point P in the global coordinate system are: Its position coordinates should also satisfy the known equations of the ship's surface coordinates: f(x,y,z)=0; Therefore, the position parameter s = s0 is determined, and thus the position coordinates of the underwater robot at position P are:

2. The underwater wall-climbing robot positioning method according to claim 1, characterized in that: When a robot needs to locate itself on a two-dimensional plane, the following steps are included: Step 1: Change the three-dimensional coordinate system to a two-dimensional coordinate system oxy, and reduce the number of guy wire fixing holes from six to three, namely a, b, and c. These holes are connected to three known points A, B, and C on the ship's wall through displacement encoders to monitor the distance between the corresponding guy wire fixing holes and the wall fixing points in real time. The relative angles between adjacent guy wire fixing holes are reduced to three, namely α, β, and φ. Step 2: Translate the global coordinate system oxy to the center of the orbit circle O(x) O ,y O The position of ) is established in a local coordinate system Ox′y′ on the orbital plane. The plane in which it is located is parallel to the two-dimensional plane of the ship's wall, with a distance of h, which can be regarded as a known quantity; Step 3: According to the coordinate transformation relationship, the position coordinates of any point Q in space satisfy the following relationship between the position coordinates (x, y) in the global coordinate system oxy and the position coordinates (x′, y′) in the local coordinate system Ox′y′: Among them, a ij =cos(e j ′,e i () is the direction cosine of the unit vector in the local coordinate system in the global coordinate system; Step 4: Let e1 and e2 be unit vectors along the two coordinate axes in the global coordinate system oxy, and e1′ and e2′ be unit vectors along the two coordinate axes in the local coordinate system Ox′y′. Then the position coordinates of the center O of the orbit (x, y, y) are... O ,y O The direction cosine α of the unit vector in the local coordinate system in the global coordinate system. ij This constitutes 6 unknowns to be determined; The unit vector in the global coordinate system and the unit vector in the local coordinate system satisfy the following relationship: And i ′=a ji And j ; The unit vector in a rectangular coordinate system satisfies the following relationship: Therefore, three independent equations can be established: Step 5: Without loss of generality, assume that the guy wire fixing hole a is exactly on the x′ axis of the local coordinate system Ox′y′, and the position coordinates of the guy wire fixing hole a in the local coordinate system are (R, 0). The position coordinates of the guy wire fixing hole a in the global coordinate system are: The distance l between the wire fixing hole a and the corresponding fixing point A can be monitored using a displacement encoder. aA Therefore, the following equation is established: Since the angle between the line Ob connecting the wire fixing hole b to the center O and the line Oa connecting the wire fixing hole a to the center O is α, the position coordinates of the wire fixing hole b in the local coordinate system Ox′y′ are (Rcosα, Rsinα), and its position coordinates in the global coordinate system are: The distance l between the wire fixing hole b and the corresponding fixing point B can be monitored using a displacement encoder. bB Therefore, the following equation is established: Similarly, a similar equation can be established for the wire fixing hole c; thus, six independent equations are established to determine six unknown position parameters x. O y O a ij (i,j = 1,2); Step 6: The position coordinates of the intersection point P of the center O of the circular track and the ship's surface along a straight line perpendicular to the track plane in the local coordinate system are (x... O ,y O Therefore, the position coordinates of the underwater robot at location P are:

3. The underwater wall-climbing robot positioning method according to claim 2, characterized in that: When the walls of ships and marine structures are planar, a two-dimensional planar positioning method based on establishing two-dimensional coordinates is used for positioning.

4. The underwater wall-climbing robot positioning method according to claim 1, characterized in that: The polygon formed by connecting the six known points A, B, C, D, E, and F on the ship is the smallest polygon covering the robot's task area.

5. A positioning device using the underwater wall-climbing robot positioning method according to any one of claims 1 to 4, characterized in that: The system includes a track, rollers, roller brackets, wire fixing holes, and wire-type displacement encoders. The track is circular, and multiple rollers are distributed circumferentially along the roller bracket and movably connected to the roller bracket via a roller shaft. The roller bracket and track are fitted together to allow the rollers to roll on the track. The roller bracket has six wire fixing holes spaced apart. There are six wire-type displacement encoders, which are installed at six points on the wall of a ship or marine structure. The wire of each wire-type displacement encoder is connected to a corresponding wire fixing hole.

6. The positioning device for a positioning method of an underwater wall-climbing robot according to claim 5, characterized in that: The device is mounted on a robot, which drives the rollers to roll on a track.

7. The underwater wall-climbing robot positioning method according to claim 5, characterized in that: The track is installed on the upper part of the robot.

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