Slope fine digging planning control method for unmanned backhoe dredger

Abstract

The application discloses a kind of slope precision excavation planning control methods of unmanned operation backhoe dredger, comprising: the terrain information is constructed by the three-dimensional terrain data of target area;Discrete processing is carried out to terrain data by planner, and for a section, sub-regions of excavation area are divided into a series of triangular regions T1 connected with slope and approximate rectangular or approximate trapezoidal regions T2 above triangle;Planner calculates excavation path, single excavation depth, soil entry point and soil exit point based on dynamic programming algorithm, and excavates layer by layer from top to bottom;For triangular region T1, the angle of shovel into the soil is optimized;Controller controls the rotation of base, large arm, small arm and shovel based on the soil entry coordinates, soil exit coordinates, angle of shovel into the soil and single excavation depth ΔH output by planner, monitors and corrects the posture of shovel in real time, and completes the excavation of a section.The application supports the unmanned operation mode of backhoe dredger, and improves the construction efficiency of underwater precision excavation.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of unmanned operation backhoe dredger slope precision excavation planning control method. BACKGROUND

[0002] In the construction scene of underwater slope precision excavation of canal channel, backhoe dredger has become an important construction equipment, but faces many challenges. Underwater terrain is complex and changeable, and there may be gullies, protrusions, alternating soft and hard soil layers, etc. The soil properties differ significantly, including silt, sand, clay and various mixed soil, due to the interference of external factors such as wind and wave flow and poor visibility of the slope below water level, so that under the traditional manual construction method, the slope flatness cannot be guaranteed, and the strict requirements of high-precision engineering cannot be met. This not only increases the workload of subsequent repair and adjustment, prolongs the construction period, but also may affect the stability and safety of the entire project.

[0003] Therefore, a kind of unmanned operation backhoe dredger slope precision excavation planning control method is provided. SUMMARY

[0004] The present application aims to overcome the existing defects and provide a kind of unmanned operation backhoe dredger slope precision excavation planning control method, which supports the unmanned operation mode of backhoe dredger and improves the construction efficiency of underwater precision excavation.

[0005] The technical solution to achieve the above-mentioned purpose is:

[0006] A kind of unmanned operation backhoe dredger slope precision excavation planning control method, comprising:

[0007] Step S1, construct terrain information by three-dimensional terrain data of target area, including initial model of target slope, reference model of target slope and terrain model to be excavated;

[0008] Step S2, the planner discretizes the terrain data, and for a certain section, divides the excavation area sub-region into a series of triangular regions T1 connected with the slope and approximately rectangular or approximately trapezoidal regions T2 above the triangle;

[0009] Step S3, the planner calculates the excavation path, single excavation depth, entry point and exit point based on dynamic programming algorithm, and excavates layer by layer from top to bottom;

[0010] Step S4, optimize the shovel entry angle for triangular region T1;

[0011] Step S5, the controller controls the rotation of the base, large arm, small arm and shovel based on the entry coordinates and exit coordinates output by the planner, as well as the entry angle and single excavation depth ΔH, real-time monitors and corrects the shovel posture, and completes the excavation of a section.

[0012] Step S6, repeating the steps S2-S5 to complete the excavation of the remaining section.

[0013] Preferably, in the step S1, the topographic information is constructed, including:

[0014] Obtaining the three-dimensional topographic data of the target region by a multi-beam underwater depth measuring device;

[0015] Processing the topographic data into a digital elevation model to generate an initial model M_i of the target slope;

[0016] Setting the flatness requirement according to the engineering requirements, i.e. the allowed elevation deviation range, the slope, depth, length and boundary line of the target slope, to generate a reference model M_r of the target slope;

[0017] Subtracting the intersection of the initial model and the reference model to obtain the terrain model to be excavated M_e=(M_i-(M_i∩M_r)).

[0018] Preferably, in the step S2, for a certain section, the excavation area is divided into sub-regions, for a slope topographic profile, the direction parallel to the horizontal plane is referred to as the x direction, and the direction perpendicular to the horizontal plane is referred to as the y direction, specifically including:

[0019] First, the terrain model to be excavated M_e is vertically divided according to the excavation depth, wherein the interval Lgrid of the division is determined by the bucket width W_bucket, i.e. lgrid=k·W_buchet, 0.8≤k≤1.0;

[0020] Then, the terrain model to be excavated M_e is horizontally divided, and the division method is: the intersection of each vertical division line and the target slope can be obtained from the previous step, and the intersection is taken as the starting point, and the horizontal division is performed to the adjacent vertical division line in the x direction;

[0021] Finally, through the division of the above two parts, the topographic profile is discretized into a series of triangular regions T1 connected to the slope and approximate rectangular or trapezoidal regions T2 above the triangular regions.

[0022] Preferably, in the step S3, the planner calculates the excavation path, excavates layer by layer from top to bottom, including:

[0023] Using a dynamic programming algorithm, the bucket state variable s is defined as a set of position (x, y) and depth d, i.e. s={x, y, d};

[0024] According to the excavation path optimization model and the constraint conditions, the optimal excavation path from the starting point to the end point is calculated, and the constraint conditions include the smoothness constraint of the excavation path and the kinematic characteristic constraint;

[0025] An optimization model is established with a target function of minimizing the length of the excavation path, the energy consumption of the excavation or the excavation time;

[0026] wherein,

[0027] The excavation path smoothness constraint includes:

[0028] The single excavation depth ΔH is limited to 10%-80% of the maximum single excavation depth H_max of the bucket and is dynamically adjusted based on the current excavation soil quality;

[0029] The slope change ΔK of the current position and the adjacent position is less than a preset slope change allowable value;

[0030] The kinematic characteristic constraint includes:

[0031] The excavation path does not exceed the excavation radius and the turning radius of the backhoe dredger;

[0032] The target function is represented as:

[0033]

[0034] In the formula, C k is a cost function designed for the constraint condition, u k is a group of actions that can be taken at the kth step of excavation, including the single excavation depth ΔH, the in-soil point coordinates, and the out-soil point coordinates, sx is the value of the bucket state variable s at the kth step, s k+1 is the value of the bucket state variable s at the k+1th step.

[0035] Preferably, in the step S4, the in-soil angle of the bucket is optimized for the triangular region T1, and the in-soil angle adjustment strategy is:

[0036] According to the distance from the reference slope surface, the in-soil angle is reduced to be slightly larger than the slope, so as to smoothly excavate to the target depth in the subsequent action:

[0037] α′=α-Δα;

[0038] In the formula, α′ is the corrected in-soil angle, α is the in-soil angle when vertical to the horizontal plane, and Δα is the correction angle, which is adjusted according to the distance from the reference slope surface, i.e., the correction angle can be determined according to the following relationship:

[0039] Δα=k·d_bucket;

[0040] In the formula, k is a correction coefficient, and d_bucket is the distance between the bucket and the reference slope surface.

[0041] Preferably, the step S5 includes:

[0042] The excavation execution phase:

[0043] The planner outputs the earth penetration coordinates, the earth emergence coordinates, and the earth penetration angle and single digging depth AH of each digging, and transmits them to the controller;

[0044] The controller controls the rotation angles of the boom, the arm and the base of the backhoe dredger, so that the bucket moves to the designated grid coordinates;

[0045] The controller controls the bucket angle to be the recommended earth penetration angle, and controls the boom to lower, so that the earth penetration depth is the recommended single digging depth AH;

[0046] The controller calculates and controls the pitching movement of the boom and the arm, controls the movement of the bucket from the earth penetration point coordinates to the earth emergence point coordinates, and completes one digging action;

[0047] Real-time monitoring and adjustment stage:

[0048] A set of RTK differential positioning equipment is used to realize real-time positioning of the bucket by using the boom angle sensor, the arm angle sensor, the bucket angle sensor, the base roll angle sensor, the base pitch angle sensor and the ship acceleration sensor;

[0049] Based on the real-time measurement of the ship acceleration and angular velocity by the acceleration sensor and the gyroscope, the translation and rotation movement trajectories of the ship and the bucket are predicted in real time, the filter prediction algorithm is used to fuse and correct the RTK positioning data, and the bucket posture is corrected.

[0050] The beneficial effects of the present application are:

[0051] 1) The present application performs discretization processing on the construction terrain information, divides the terrain section into a series of sub-regions, and calculates the digging path, the single digging depth, the earth penetration point and the earth emergence point based on the dynamic programming algorithm for different regions. The bucket earth penetration angle is optimized for the near slope region, which can effectively improve the slope flatness and reduce over-digging and under-digging;

[0052] 2) The controller used in the present application measures the ship acceleration and angular velocity in real time based on the acceleration sensor and the gyroscope, predicts the translation and rotation movement trajectories of the ship and the bucket in real time, uses the filter prediction algorithm to fuse and correct the RTK positioning data, and corrects the bucket posture, which can effectively improve the position control accuracy of the bucket;

[0053] In summary, the present application can support the unmanned operation mode of the backhoe dredger by using the high-precision planning control method, and improve the construction efficiency of underwater precision digging. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 is a flowchart of a slope precision digging planning control method of an unmanned backhoe dredger of the present application;

[0055] Figure 2 is a schematic diagram of terrain data discretization and segmentation in the present application. DETAILED DESCRIPTION

[0056] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms 'center', 'upper', 'lower', 'left', 'right','vertical', 'horizontal', 'inner', 'outer', etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms 'first','second', 'third' are only for the purpose of description, and cannot be understood as indicating or implying opposite importance.

[0057] The present application will be further described below in conjunction with the drawings.

[0058] As shown in Figure 1 , a slope fine excavation planning control method for unmanned counter-dig dredgers, comprising:

[0059] Step S1, constructing terrain information through three-dimensional terrain data of a target area, including an initial model of a target slope, a reference model of the target slope, and a terrain model to be excavated.

[0060] In the embodiment, the terrain information is constructed, including:

[0061] Obtaining three-dimensional terrain data of the target area through a multi-beam underwater depth measuring device;

[0062] Processing the terrain data into a digital elevation model to generate the initial model M_i of the target slope;

[0063] Setting the flatness requirement, i.e. the allowed elevation deviation range, the slope, depth, length, and boundary line of the target slope according to engineering requirements to generate the reference model M_r of the target slope;

[0064] Subtracting the intersection of the initial model and the reference model to obtain the terrain model to be excavated M_e = (M_i-(M_i∩M_r)).

[0065] Step S2, the planner performs discrete processing on the terrain data, and for a certain cross section, divides the excavation area sub-region into a series of triangular regions T1 connected to the slope and approximately rectangular or approximately trapezoidal regions T2 above the triangular regions, as shown in Figure 2 .

[0066] In the embodiment, for a certain section, the excavation area is divided into sub-regions, for a slope terrain profile, the direction parallel to the horizontal plane is referred to as the x direction, and the direction perpendicular to the horizontal plane is referred to as the y direction, and specifically includes:

[0067] First, the to-be-excavated terrain model M_e is vertically divided according to the excavation depth, wherein the interval Lgrid of the division is determined by the bucket width W_bucket, that is, Lgrid=k·W_buchet, 0.8≤k≤1.0;

[0068] Then, the to-be-excavated terrain model M_e is horizontally divided, and the division method is as follows: the intersection point of each vertical division line and the target slope can be obtained from the previous step, and the intersection point is taken as the starting point, and the horizontal division is performed to the adjacent vertical division line in the x direction;

[0069] Finally, through the division of the above two parts, the terrain profile is discretized into a series of triangular regions T1 connected to the slope and approximate rectangular or trapezoidal regions T2 above the triangular regions;

[0070] Among them, for the trapezoidal region T2, the step S3 is used to optimize the excavation path; for the triangular region T1, on the basis of step S3, step S4 is added to optimize the bucket digging angle to avoid over-excavation.

[0071] Step S3, the planner calculates the excavation path, single excavation depth, entry point and exit point based on the dynamic programming algorithm, and excavates layer by layer from top to bottom.

[0072] In the embodiment, the planner calculates the excavation path and excavates layer by layer from top to bottom, including:

[0073] The dynamic programming algorithm is used to define the bucket state variable s as a set of positions (x, y) and depths d, that is, s={x, y, d};

[0074] According to the path optimization model and the constraint conditions, the optimal excavation path from the starting point to the ending point is calculated, and the constraint conditions include the smoothness constraint of the excavation path and the kinematic characteristic constraint;

[0075] The optimization model is established with the minimum excavation path length, excavation energy consumption or excavation time as the objective function;

[0076] Among them,

[0077] The smoothness constraint of the excavation path includes:

[0078] The single excavation depth ΔH is limited to 10%-80% of the maximum single excavation depth H_max of the bucket and is dynamically adjusted based on the current excavation soil quality;

[0079] The slope change ΔK of the current position and the adjacent position is less than a preset slope change allowable value;

[0080] The kinematic property constraint comprises:

[0081] The digging path does not exceed the digging radius and the turning radius of the backhoe dredger;

[0082] The objective function is expressed as:

[0083]

[0084] In the formula, C k is a cost function designed for the constraint condition, u k is a group of actions that can be taken in the kth step of digging, including a single digging depth ΔH, an entry point coordinate, and an exit point coordinate, s k is a value of the bucket state variable s in the kth step, s k+1 is a value of the bucket state variable s in the k+1th step.

[0085] Step S4: optimizing the bucket entry angle for the triangular region T1.

[0086] In the embodiment, if the ideal entry angle of the bucket is perpendicular to the horizontal plane, the bucket may generate an additional digging action after entry due to the linkage of the boom and the stick, resulting in over-digging. Therefore, the entry angle needs to be optimized to ensure the flatness of the slope. The entry angle adjustment strategy is:

[0087] According to the distance from the reference slope surface, the entry angle is reduced to be slightly larger than the slope, so as to smoothly dig to the target depth in the subsequent action:

[0088] α′=α-Δα;

[0089] In the formula, α′ is the corrected entry angle, α is the entry angle when perpendicular to the horizontal plane, and Δα is the correction angle, which is adjusted according to the distance from the reference slope surface. That is, the correction angle can be determined according to the following relationship:

[0090] Δα=k·d_bucket;

[0091] In the formula, k is a correction coefficient, and d_bucket is the distance between the bucket and the reference slope surface.

[0092] Step S5: the controller controls the rotation of the base, the boom, the stick, and the bucket based on the entry coordinates and the exit coordinates output by the planner, as well as the entry angle and the single digging depth ΔH, and monitors and corrects the bucket posture in real time to complete one cross-section digging.

[0093] In the embodiment, step S5 comprises:

[0094] Excavation execution stage:

[0095] The planner outputs the earth entry coordinates, earth exit coordinates, and earth entry angle, single excavation depth ΔH of each excavation, and transmits them to the controller;

[0096] The controller controls the rotation angles of the boom, arm and base of the backhoe dredger, so that the bucket moves to the specified grid coordinates;

[0097] The controller controls the bucket angle to be the recommended earth entry angle, and controls the boom to lower, so that the earth entry depth is the recommended single excavation depth ΔH;

[0098] The controller calculates and controls the pitch movement of the boom and arm, controls the bucket to move from the earth entry point coordinates to the earth exit point coordinates, and completes one excavation action;

[0099] Real-time monitoring and adjustment stage:

[0100] A set of RTK differential positioning equipment is used to real-time position the bucket, using the boom angle sensor, arm angle sensor, bucket angle sensor, base roll angle sensor, base pitch angle sensor, and ship acceleration sensor.

[0101] Based on the real-time measurement of ship acceleration and angular velocity by acceleration sensor and gyroscope, the translation and rotation movement trajectories of the ship and the bucket are real-time predicted, the filtering prediction algorithm is used to fuse and correct the RTK positioning data, and the bucket attitude is corrected.

[0102] Step S6, repeat the steps S2-S5 to complete the excavation of the remaining sections.

[0103] The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A slope fine excavation planning control method for an unmanned operating backhoe dredger, characterized by, Comprise: Step S1, constructing terrain information by three-dimensional terrain data of target area, including initial model of target slope, reference model of target slope and terrain model to be excavated; Step S2, planner discretizes terrain data, for a section, divides excavation area sub-region into a series of triangular regions T1 connected with the slope and approximately rectangular or trapezoidal regions T2 above the triangle; Step S3, planner calculates excavation path, single excavation depth, entry point and exit point based on dynamic programming algorithm, excavates layer by layer from top to bottom; Step S4, optimizing bucket entry angle for triangular region T1; Step S5, the controller controls the rotation of the base, the large arm, the small arm, and the bucket based on the in-soil coordinates, the out-of-soil coordinates, and the in-soil angle and the single-digging depth output by the planner , controls the rotation of the base, the large arm, the small arm, and the bucket, real-time monitors and corrects the bucket posture, and completes one section of excavation. Step S6, repeating steps S2-S5 to complete the excavation of the remaining section; In step S2, for a section, the excavation area sub-region is divided, for a slope terrain profile, the direction parallel to the horizontal plane is called x direction, and the direction perpendicular to the horizontal plane is called y direction, which specifically comprises: First, the terrain model to be excavated is divided vertically according to the depth of excavation at intervals determined by the width of the bucket , i.e. , 0.8 ≤ ≤ 1.0;​ Then, the terrain model to be excavated is divided horizontally The horizontal division is performed by taking the intersection of each vertical division line and the target slope as a starting point and horizontally dividing in the x direction to the adjacent vertical division line. Finally, the terrain profile is discretized into a series of triangular regions T1 connected with the slope and approximately rectangular or trapezoidal regions T2 above the triangle by the above two parts.

2. The method according to claim 1, wherein, In step S1, the terrain information is constructed, including: Obtaining three-dimensional terrain data of target area by multi-beam underwater depth measuring equipment; processing the terrain data into a digital elevation model to generate an initial model of the target slope ; According to the engineering requirement, the flatness requirement, i.e. the allowed elevation deviation range, the slope, the depth, the length and the boundary line of the target side slope are set to generate the reference model of the target side slope ; The initial model is subtracted from its intersection with the reference model to obtain the terrain model to be mined .

3. The method according to claim 1, wherein, In step S3, the planner calculates the excavation path and excavates layer by layer from top to bottom, including: A dynamic programming algorithm is used to define the bucket state variable within the sub-region for a set of positions and depths , i.e. ; According to the excavation path optimization model and the constraint conditions, the optimal excavation path from the starting point to the ending point is calculated, and the constraint conditions include excavation path smoothness constraint and kinematic characteristic constraint; The optimization model is established with the minimum excavation path length, excavation energy consumption or excavation time as the objective function; Wherein, The excavation path smoothness constraint includes: Single dig depth Limit to 10-80% of the bucket's maximum single dig depth and dynamically adjust based on the current dig soil ​ Slope change of current position and adjacent position less than a preset slope change allowance value; The kinematic characteristic constraint includes: The excavation path does not exceed the excavation radius and turning radius of the backhoe dredger; The objective function is expressed as: ； wherein a cost function designed as a constraint, is the value of the Step excavating the set of possible actions, including single excavation depth , point of entry coordinates, point of exit coordinates, is the value of the bucket state variable in the value of the Step, is the value of the bucket state variable in the value of the Step.

4. The method according to claim 1, wherein, In step S4, the bucket entry angle is optimized for triangular region T1, and the entry angle adjustment strategy is: According to the distance from the reference slope surface, the entry angle is reduced to be slightly larger than the slope, so as to smoothly excavate to the target depth in the subsequent action: ； wherein is the corrected angle of entry into the ground, is the angle of entry into the ground when perpendicular to the horizontal plane, is the correction angle, which is determined in dependence on the distance from the reference slope, i.e. in dependence on the following relationship: ； wherein is a correction factor, is the distance of the bucket from the reference slope.

5. The method of claim 1, wherein the method further comprises: The step S5 includes: Excavation execution stage: The planner outputs the coordinates of entry into the ground, the coordinates of exit from the ground, and the angle of entry into the ground, the depth of single digging for each digging and transmits to the controller; The controller controls the rotation angles of the boom, arm and base of the backhoe dredger, so that the bucket moves to the specified grid coordinates; The controller controls the bucket angle to be the recommended digging-in angle, and controls the lowering of the large arm so that the digging-in depth is the recommended single-digging depth ; The controller calculates and controls the pitch movement of the boom and arm, controls the bucket to move from the entry point coordinates to the exit point coordinates, and completes one excavation action; Real-time monitoring and adjustment stage: A set of RTK differential positioning equipment is used to real-time position the bucket, including boom angle sensor, arm angle sensor, bucket angle sensor, base roll angle sensor, base pitch angle sensor and ship body acceleration sensor; Based on the real-time measurement of ship body acceleration and angular velocity by acceleration sensor and gyroscope, the translation and rotation motion trajectories of the ship body and the bucket are predicted in real time, and the filter prediction algorithm is used to fuse and correct the RTK positioning data to correct the bucket attitude.

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