Method and System for Evaluating Comprehensive Environmental Costs of Task Schemes Based on Spatiotemporal Voxels

Abstract

The present invention belongs to the field of task execution environment evaluation, and particularly relates to a method and system for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels. A spatio-temporal comprehensive environmental impact model for describing the laws of spatio-temporal environmental impact for tasks is constructed in a spatio-temporal coordinate system; the spatio-temporal comprehensive environmental impact model is rasterized to construct spatio-temporal voxels, and the spatio-temporal trajectory during the execution of the task plan is obtained through trajectory tracking. The comprehensive environmental cost of the task plan is calculated according to the occurrence and accumulation laws of the cost of the spatio-temporal voxels passed through. By constructing a comprehensive environmental impact model based on spatio-temporal voxels, the present invention extends the time dimension on the basis of the spatial cost law of the task environment to realize the situation of continuous change in time at any point in space, can reflect the impacts of various factors of time and space on the task, comprehensively and reasonably realizes the spatio-temporal environmental evaluation of the task plan, and the analysis principle is close to the actual situation, having a good application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of task execution environment evaluation, and particularly relates to a method and system for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels. Background Art

[0002] In a specific field, a task refers to a single-stage action in physical space. A task is a broad concept, which is an ordered set of a series of interrelated actions carried out by an action unit to complete the responsibilities assumed or achieve a specific purpose under certain environmental and spatio-temporal constraints, including actions in multiple stages in physical space and non-physical space, as well as the association and coordination between stages. The evaluation of the impact of the environment on a task cannot focus only on the environment. In fact, in addition to the environment, the execution of a task is also affected by the situation and the capabilities of both sides during the implementation of the task. Even in some cases, the situation and capability factors are the main reasons. Therefore, it is unrealistic to study the impact of the environment on a task in isolation. It is necessary to combine the factors of both sides participating in the combat task and place it under the influence of the situation to scientifically evaluate the comprehensive impact of the environment. To some extent, the situation and capabilities are also affected by the environment. The study of the impact on the situation and capabilities is itself an extension of the study of the impact of the environment. When analyzing the current state and development trend of a maneuver task, it mainly includes two parts: situation estimation and threat estimation. The quantitative or qualitative description of the enemy, ourselves, friendly forces, and events is the basis of situation expression. As an important factor that cannot be ignored in the execution of a task, capability plays a relatively important role in the environmental analysis facing the task. It includes many elements such as the personnel capabilities, scale, training level, biological habits (such as sleep and eating habits, etc.), capabilities and states, and support levels of the task executor and related situation objects (such as enemy and friendly units); these elements will have a significant impact on the execution of the task under the comprehensive influence of the environment. In the process of evaluating the impact of the environment on a task, fully considering the capability factor is the key to the scientificity and pertinence of the evaluation method. The evaluation that ignores the capability factor cannot reflect the real environmental impact. Moreover, factors such as the situation, capabilities, and environment are all continuously changing or mutating over time. The static research method cannot reflect the real impact of the dynamic environment on the task. Time is the only parameter running through these changes. Therefore, the environment, situation, and capabilities can all be regarded as complex time-related functions. The growth rate of the spatio-temporal comprehensive cost of a task is a field that is continuous and irregularly distributed over time and space. It is difficult to calculate the task cost in such an unpredictable environment. It is necessary to establish a unified model to analyze its distribution. In traditional methods, the comprehensive spatio-temporal environment analysis facing a task uses a two-dimensional mathematical model of the impact of the spatial environment to uniformly express the comprehensive impact of the environment on the task. Although this two-dimensional data model of the spatial environment impact can show the environmental cost law in different spaces, it cannot reflect the impact brought by the change of the environment over time, and there are certain limitations in the environmental evaluation of the task execution plan. Summary of the Invention

[0003] To this end, the present invention provides a method and system for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels. By constructing a comprehensive environmental impact model based on spatio-temporal voxels, the time dimension is extended on the basis of the law of the spatial cost of the task environment to realize the continuous change of any point in space with respect to that point in time, which can reflect the influence of various factors of time and space on the task, and can more comprehensively and reasonably realize the spatio-temporal environmental evaluation of the task plan, and the principle of comprehensive environmental analysis is closer to the actual situation.

[0004] According to the design solution provided by the present invention, a method for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels is provided, including:

[0005] Construct a spatio-temporal comprehensive environmental impact model in the spatio-temporal coordinate system for describing the law of spatio-temporal environmental impact on the task;

[0006] Perform rasterization processing on the spatio-temporal comprehensive environmental impact model. Divide the space-time into cubic space-time units along the axes of the spatio-temporal coordinate system at the same spatial and time intervals, and use the cubic space-time units as spatio-temporal voxels. The task execution process is regarded as a series of continuous straight-line motions. Based on the spatio-temporal voxels and using trajectory tracking to obtain the spatio-temporal trajectory during the execution of the target task, and evaluate the comprehensive environmental cost of the target task plan according to the cost of the spatio-temporal voxels passed by the spatio-temporal trajectory.

[0007] As the method for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels of the present invention, further, the spatio-temporal comprehensive environmental impact model extends the time dimension on the basis of the law of the spatial environmental cost, and uses the spatio-temporal coordinate system to record the cumulative growth rate of the environmental cost during the task execution due to environmental, situation, and ability factors of a spatial point with respect to a time point. Among them, a three-dimensional rectangular coordinate system is established with a point on the ground surface as the origin, the eastward direction as the X-axis, the northward direction as the Y-axis, and the time T as the Z-axis vertically upward, and this three-dimensional rectangular coordinate system is used as the spatio-temporal coordinate system.

[0008] As the method for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels of the present invention, further, in the model rasterization process, the space is rasterized along the X-axis and Y-axis of the spatio-temporal coordinate system at the same spatial interval, and a spatial grid center is determined for each spatial grid; the time is divided at the same time interval along the T-axis, and the smallest spatio-temporal unit after rasterizing the time and space is used as the spatio-temporal voxel for simplifying the complexity of environmental spatial changes and time changes.

[0009] As the method for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels of the present invention, further, in the spatio-temporal comprehensive environmental impact model, the total cost value of the task execution plan is obtained by tracking the cost value corresponding to each spatio-temporal voxel along the spatio-temporal trajectory of the task execution process, and the total cost value is used to evaluate the actual performance of the plan during task execution.

[0010] As the method for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels of the present invention, further, in the spatio-temporal coordinate system of the spatio-temporal comprehensive environmental impact model, the starting and ending spatio-temporal coordinates of task execution are set, and the movement trajectory of the task execution process is regarded as several straight-line movements continuously passing through the corresponding spatio-temporal voxels, and the spatio-temporal trajectory of the task execution process is obtained based on the straight-line segments at the time points of entering and exiting the spatio-temporal voxels.

[0011] As the method for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels of the present invention, further, the travel length and residence time within each spatio-temporal voxel passed through on the spatio-temporal trajectory are obtained by using the spatio-temporal coordinates of the spatio-temporal points when the task execution enters or exits the spatio-temporal voxel in the model, and the comprehensive environmental cost of the task execution plan is obtained through the cost growth rate of each spatio-temporal voxel passed through by the spatio-temporal trajectory, the residence time within the corresponding spatio-temporal voxel, and the travel length.

[0012] As the method for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels of the present invention, further, assume that the cost generated by the task execution plan in the i-th spatio-temporal voxel Then the comprehensive environmental cost of the task execution plan is where n represents the number of spatio-temporal voxels passed through by the spatio-temporal trajectory in sequence, represents the cost growth rate of the i-th spatio-temporal voxel, represents the residence time of the spatio-temporal trajectory in the i-th spatio-temporal voxel, represents the travel length of the spatio-temporal trajectory in the i-th spatio-temporal voxel.

[0013] Further, the present invention also provides a system for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels, including: a model construction module and a cost evaluation module, where

[0014] The model construction module is used to construct a spatio-temporal comprehensive environmental impact model in the spatio-temporal coordinate system for describing the spatio-temporal environmental impact law for the task.

[0015] A cost evaluation module is used to rasterize the spatio-temporal comprehensive environment impact model, divide the spatio-temporal into spatio-temporal unit cubes along the axes of the spatio-temporal coordinate system at the same spatial and time intervals, take the spatio-temporal unit cubes as spatio-temporal voxels, regard the task execution process as several consecutive straight-line motions, obtain the spatio-temporal trajectory during the execution of the target task based on the spatio-temporal voxels and using trajectory tracking, and evaluate the comprehensive environment cost of the target task plan according to the cost of the spatio-temporal voxels passed by the spatio-temporal trajectory.

[0016] Advantages of the present invention:

[0017] By constructing a comprehensive environment impact model based on spatio-temporal voxels, the present invention extends the time dimension on the basis of the spatial cost law of the task environment space to realize the continuous change of any point in space and the situation at that point in time, can reflect the influence of various factors of time and space on the task, more comprehensively and reasonably realizes the spatio-temporal environment evaluation of the task plan, the comprehensive environment cost analysis is closer to the actual situation, and has good application prospects. Description of the drawings

[0018] Figure 1 Schematic diagram of the comprehensive environment cost evaluation process of the task plan based on spatio-temporal voxels in the embodiment;

[0019] Figure 2 Schematic diagram of the spatio-temporal coordinate system in the embodiment;

[0020] Figure 3 Schematic diagram of the spatio-temporal environment model after rasterization in the embodiment;

[0021] Figure 4 Schematic diagram of the spatio-temporal trajectory calculation process in the embodiment;

[0022] Figure 5 Schematic diagram of the spatio-temporal comprehensive environment impact model in the embodiment;

[0023] Figure 6 Schematic diagram of the static environment planning scheme in the embodiment. Detailed implementation manners

[0024] To make the purpose, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the drawings and technical solutions.

[0025] An embodiment of the present invention provides a method for comprehensively evaluating the environment cost of a task plan based on spatio-temporal voxels. Refer to Figure 1 as shown, including:

[0026] S101. Construct a spatio-temporal comprehensive environment impact model for describing the spatio-temporal environment impact law for the task in the spatio-temporal coordinate system;

[0027] S102. Perform rasterization processing on the spatio-temporal comprehensive environment impact model. Divide the spatio-temporal into spatio-temporal unit cubes along the axes of the spatio-temporal coordinate system at the same spatial and temporal intervals, and regard the spatio-temporal unit cubes as spatio-temporal voxels. The task execution process is regarded as several consecutive straight-line motions. Based on the spatio-temporal voxels and using trajectory tracking to obtain the spatio-temporal trajectory during the execution of the target task, and evaluate the comprehensive environment cost of the target task plan according to the cost of the spatio-temporal voxels passed by the spatio-temporal trajectory.

[0028] By constructing an environmental comprehensive impact model based on spatio-temporal voxels, expanding the time dimension on the basis of the task environment space cost law to realize the situation of continuous change in time at any point in space, it can reflect the influence of various factors of time and space on the task, more comprehensively and reasonably realize the spatio-temporal environment assessment of the task plan, and the comprehensive environment cost analysis is closer to the actual situation and is convenient for application in the actual scenario.

[0029] The two-dimensional space environment impact model can show the environmental cost laws of different spaces, but it cannot reflect the influence brought by the change of the environment over time. Therefore, in the embodiments of this case, the spatio-temporal comprehensive environment impact model expands the time dimension on the basis of the space environment cost law, and uses the spatio-temporal coordinate system to record the cumulative growth rate of the environmental cost during the task execution due to environmental, situation, and ability factors at a spatial point over time points. Among them, a three-dimensional rectangular coordinate system is established with a point on the ground surface as the origin, the eastward direction as the X-axis, the northward direction as the Y-axis, and the time T as the Z-axis vertically upward, and this three-dimensional rectangular coordinate system is used as the spatio-temporal coordinate system.

[0030] As Figure 2 shown, (a) represents the spatio-temporal coordinate system of the two-dimensional space, and (b) represents the space coordinate system of the three-dimensional space. Both coordinate systems are three-dimensional coordinate systems, but the coordinate meanings are completely different. The definition of the spatio-temporal coordinate system in the two-dimensional space is consistent with the similar coordinate system in spatio-temporal geography. To uniformly express the dynamic change of the space environment over time, in the embodiments of this case, through the spatio-temporal comprehensive environment impact model, the spatio-temporal coordinate system described in Figure 2 is established to record the environmental impact law of any spatio-temporal. Record the spatio-temporal growth rate of the comprehensive environmental cost at any position (x, y, t) in the spatio-temporal coordinate system to record the rate of change of the cumulative cost of the environment, situation, and ability on the task execution at the spatial point (x, y) at time t. The meaning of is related to the cost. For the shortest time planning, is the minimum time required to move a unit distance, that is, the shortest time consumption cost rate And for the comprehensive path cost analysis,

[0031] As the method for comprehensively evaluating the environmental cost of the task solution based on spatio-temporal voxels in the embodiment of the present invention, further, in the model rasterization process, the space is rasterized along the X-axis and Y-axis of the spatio-temporal coordinate system at the same spatial interval, and a spatial grid center is determined for each spatial grid; it is segmented along the T-axis at the same time interval, and the smallest spatio-temporal unit after rasterizing time and space is used as the spatio-temporal voxel for simplifying the complexity of environmental spatial changes and time changes.

[0032] The task along L m The overall spatio-temporal cost is applicable to the task execution plan moving along any spatio-temporal trajectory. By integrating through the overall spatio-temporal cost formula, the relevant environmental cost can be obtained. However, the changes of the environment in time and space are both irregular, and there are difficulties in the actual operation process. Therefore, in the embodiment of this case, by rasterizing the spatio-temporal environment, as Figure 3 shown, the spatio-temporal is divided into spatio-temporal unit cubes (spatio-temporal voxels, abbreviated as voxels) along the X-Y-T three axes at the same spatial and time intervals. It is approximately considered that the spatio-temporal growth rate of the comprehensive environmental cost in the same spatio-temporal unit is consistent. The environmental membership problem in the rasterization process can be set as: in space, the rasterized environment belongs to the part of the environment that has the greatest impact on the task; in time, the state of the environment belongs to the environmental state at the geometric center of the voxel. What is expressed is the spatio-temporal rate of cost accumulation. In addition to being related to the spatio-temporal environment, it may also be related to other factors, such as the driving direction and historical trajectory during task execution. Therefore, even after the environmental rasterization, it is not necessarily a numerical value, but represents a cost accumulation law.

[0033] Theoretically, the process of understanding the impact on the environment is the calculation process for each voxel . However, in fact, it is unrealistic to calculate all the of all the voxels in the investigated spatio-temporal region, and the cost of such a huge amount of environmental evaluation is huge, which will lead to an explosion problem in the calculation process. To solve this problem, in the embodiment of this case, the spatio-temporal trajectory can be used, that is, which voxel is used and how much is generated during the evaluation process, and the environment is evaluated accordingly.

[0034] The significance of discretization is to simplify the complex change law. When the size of the rasterized spatio-temporal interval is appropriate, it can be approximately considered that the environment is similar within the spatio-temporal it represents, and all its cost laws are also the same. As Figure 3 shown, if (x0, y0, t0) is the geometric center point of the green voxel shown in the figure, and w′(·) is the approximate expression of the cost w(·) within the voxel, then w can be approximately expressed by the following formula:

[0035]

[0036] As the method for comprehensively evaluating the environmental cost of the task based on spatio-temporal voxels in the embodiments of the present invention, further, in the spatio-temporal comprehensive environmental impact model, the total cost value of the task execution plan is obtained by tracking the cost value corresponding to each spatio-temporal voxel passed by the spatio-temporal trajectory during the task execution process, and the total cost value is used to evaluate the actual performance of the plan during the task execution. Further, in the spatio-temporal coordinate system of the spatio-temporal comprehensive environmental impact model, the starting and reaching spatio-temporal coordinates of the task execution are set, and the movement trajectory during the task execution is regarded as several straight-line movements continuously passing through the corresponding spatio-temporal voxels, and the spatio-temporal trajectory during the task execution process is obtained based on the straight-line segments at the time points of entering and exiting the spatio-temporal voxels. Further, the travel length and residence time within each spatio-temporal voxel passed by the spatio-temporal trajectory are obtained by using the spatio-temporal coordinates of the spatio-temporal points when the task execution enters or exits the spatio-temporal voxel, and the comprehensive environmental cost of the task execution plan is obtained through the cost growth rate of each spatio-temporal voxel passed by the spatio-temporal trajectory, the residence time within the corresponding spatio-temporal voxel, and the travel length.

[0037] To evaluate the cost of the task execution plan based on the spatio-temporal comprehensive environmental impact model, it is first necessary to obtain which spatio-temporal voxels the known plan will pass through, as well as the residence time length and the moving spatial distance within each spatio-temporal voxel. This process is the spatio-temporal tracking process of the movement trajectory. The movement in the spatio-temporal comprehensive environmental impact model can be regarded as several continuous straight-line movements, and any complex movement trajectory can be approximated in this way. As Figure 4 shown in the figure is a straight-line movement from spatio-temporal point S to spatio-temporal point E in a period of time and space. A part of the voxels A0, B0, B1 are drawn in the figure, where A0 and B0 are adjacent in space and have the same time, and B0 and B1 have the same space and are adjacent in time. Spatio-temporal point S is a spatio-temporal point of spatial point A on its spatio-temporal trajectory L A ; spatio-temporal point E is a spatio-temporal point of spatial point B on its spatio-temporal trajectory L B . Assume that the task execution plan starts from S and follows the spatio-temporal trajectory shown in the figure, passing through spatio-temporal points M0 and M1 to reach E. The spatio-temporal coordinates of the endpoints of each straight-line segment in the specific plan are known (the spatio-temporal coordinates of S and E in the figure are known), and the driving speed and direction of this section of the task journey are known. If the spatio-temporal coordinates of each spatio-temporal point of entering or exiting the voxel (the spatio-temporal coordinates of M0 and M1 in the figure) are obtained, the travel length and residence time within each voxel passed by the spatio-temporal trajectory (the three voxels passed by A0, B0, and B1 in the figure) can be calculated.

[0038] During the specific model solving calculation, the driving direction i can be calculated by using the spatial coordinates of A and B through the formula i = arctan((y B - y A ) / (x B-x B ) calculated, this value remains unchanged when each voxel between these two points moves, and the velocities in the x and y axis directions According to the scheme, let upper(x) and floor(x) be the downward and upward rounding functions respectively, and forward(x) and backward(x) can be defined as the backward and forward rounding functions respectively. Denote the grid intervals of the x, y, and t axes as d x , d y , d t , and assume that the coordinate mark at the start of movement in the j-th spatio-temporal voxel is (x j , y j , t j ), the maximum remaining movement time within this voxel and the geometric center coordinates of the voxel can be expressed as:

[0039]

[0040] During this period of time, without considering the spatial boundaries of the voxel, the maximum travel distances in the x and y axis directions are respectively Without considering the time boundaries of the spatio-temporal voxel, the maximum travel distances in the x and y axis directions are respectively If other axes are not considered, denote the shortest times to penetrate from the T axis, X axis, and Y axis as The corresponding formulas are Then the earliest penetration time Δt j is expressed as The axis is the axis corresponding to the shortest time.

[0041] After completing the above calculations, if it means that the end point has not been reached when passing through the j-th voxel, and it will continue to move into the j + 1-th voxel. The coordinates when entering are Repeat the above steps in the next voxel until the end point can be reached in the n-th voxel. In this case, Δt n is corrected to and the calculation ends.

[0042] Through the above method, the tracking of the straight-line segment movement in the voxel can be completed, and the spatio-temporal coordinates when entering and exiting each voxel of the spatio-temporal trajectory can be obtained. The trajectory is a uniform linear motion within the voxel, that is, the straight-line segment connecting the spatio-temporal points when entering and exiting the voxel (such as Figure 4For the middle straight line segment M0M1), through the above content, it is possible to trace which voxels the specific cross-country plan will pass through, as well as the length of time staying in each voxel and the spatial distance of movement.

[0043] Suppose the spatio-temporal trajectory of the task execution plan obtained through movement trajectory tracking will sequentially pass through n spatio-temporal voxels. Denote the cost growth rate in the i-th spatio-temporal voxel as , the trajectory stays in this spatio-temporal voxel for time , and the length of the traveling space is Then the cost W generated by the task execution plan in the i-th voxel of the model will be i as The overall cost W of the entire plan is

[0044] Furthermore, based on the above method, the embodiment of the present invention also provides a comprehensive environmental cost evaluation system for task plans based on spatio-temporal voxels, including: a model construction module and a cost evaluation module, where,

[0045] The model construction module is used to construct a spatio-temporal comprehensive environmental impact model in the spatio-temporal coordinate system for describing the laws of spatio-temporal environmental impacts for tasks;

[0046] The cost evaluation module is used to perform rasterization processing on the spatio-temporal comprehensive environmental impact model, divide the spatio-temporal into spatio-temporal unit cubes along the axes of the spatio-temporal coordinate system at the same spatial and time intervals, use the spatio-temporal unit cubes as spatio-temporal voxels, regard the task execution process as a continuous series of straight-line motions, obtain the spatio-temporal trajectory during the execution of the target task based on the spatio-temporal voxels and using trajectory tracking, and evaluate the comprehensive environmental cost of the target task plan according to the costs of the spatio-temporal voxels passed by this spatio-temporal trajectory.

[0047] Unless otherwise specifically stated, the relative steps, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0048] To verify the effectiveness of the plan, the plan of this case will be further explained below with reference to experimental data:

[0049] In the cross-country path planning problem, since the environment changes continuously over time, theoretically, if a certain cross-country plan is planned at the start time of the task, if the future rainfall increases, the actual consumption time will be greater than the planned time, and vice versa. In the experiment, the above experimental scenario will be constructed to conduct experiments on the environmental comprehensive impact model based on spatio-temporal voxels of the plan of this case to verify whether the model can reflect the impact of the continuously changing rainfall process on the cost of the shortest consumption time of the task. The experiment is divided into the following two groups:

[0050] The first set of experiments uses a small-scale simulation scenario with continuous rainfall; the spatio-temporal rasterization scheme uses a high spatial resolution and a low temporal resolution. This set of experiments simulates the situation where future rainfall will become heavier.

[0051] The second set of experiments uses a scenario and a spatio-temporal rasterization method that are basically the same as those in the first set. The only difference is that the rainfall trend change is adopted. This set of experiments simulates the situation where future rainfall will become lighter.

[0052] When constructing the environmental data on the impact of rainfall on the maximum safe driving speed, c a Mark the impact parameter of artificial buildings. In the area with artificial buildings, c a Is 0, otherwise it is 1; c t Mark the terrain impact parameter. In the area where the slope is greater than 30 degrees, c t = 0, and in other areas, it is proportional to the slope; c CH = f CH (r), c ML = f ML (r), c SM = f SM (r) respectively represent the influence parameter functions of rainfall amount r on speed on three types of soil; the spatial grid interval used in the comprehensive environmental impact matrix is 500 meters, and the temporal grid interval is 50 seconds. Assume that the maximum safe speed of the motor vehicle is proportional to the traction force size, c CH , c ML , c SM Can be obtained by fitting the experimental data. Since an isotropic speed scenario is adopted, the corresponding shortest time consumption cost rate is a scalar, denoted by Marked (if an anisotropic speed scenario is considered, the shortest time consumption cost rate is also related to the driving direction and should be represented by a spatial vector). The That can be achieved in any spatial cell network is a function of t, expressed as:

[0053]

[0054] As Figure 5 Shown, it is the spatio-temporal environmental comprehensive impact model of the shortest time consumption cost evaluated and drawn during a certain time period in the first set of experiments, showing the shortest time consumption rate in each voxel. It should be noted that in actual applications, it is not necessary to evaluate all spatio-temporal voxels, and only the voxels that need to be used need to be evaluated. In the scheme, only for the purpose of effect display, all voxels in a certain range of time and space are evaluated. As Figure 6As shown in the figure, in the first group of experiments, the off-road task of one experiment requires maneuvering from the position of the left arrow shown in the figure to the position of the right arrow. If the traditional method is used for off-road planning at the moment of t0 = 0s (using the Dijkstra algorithm to search for the minimum-cost path in the two-dimensional cost surface shown in the figure in the eight-neighborhood), the off-road plan calculated is shown as the light-colored connected path in the figure. There is no rainfall at the moment of t0, and it is estimated that the entire plan will consume 2787.78 seconds using the traditional method. However, rainfall will start in a future period and the rainfall amount will gradually increase. The main body of the task will definitely be affected by the rainfall and thus its traveling speed will decrease. Obviously, the time to reach the end point will exceed the time predicted by the traditional static method; if the spatio-temporal trajectory tracking based on spatio-temporal voxels in the solution of this case is used to re-evaluate the task execution plan at the minimum time consumption cost rate allowed for each spatio-temporal voxel passed by, the result is 5568.48 seconds, which is much higher than the time evaluated in the original static environment. Obviously, the evaluation result of the solution of this case is more in line with the actual situation of increasing rainfall in the first group of experiments.

[0055] To evaluate the difference between the evaluation result using the environmental impact model in traditional static planning and the evaluation result in the comprehensive environmental impact model based on spatio-temporal voxels in the solution of this case, an evaluation result difference index γ can be defined, such as γ = t r -t s / t r . Where t s is the predicted consumption time of the static planning path, and t r is the time evaluated in the model of this article for the static planning path. Tables 1 and 2 list the γ values of multiple experiments with gradually increasing and gradually decreasing rainfall over time (assuming that all tasks start at the moment of t0). It can be seen from the results that in the case of gradually increasing rainfall, the predicted time of the traditional static evaluation method is always lower than the consumption time evaluated by the model of this case, while in the case of gradually decreasing rainfall, the predicted time of the traditional static evaluation method is always higher than the consumption time evaluated by the model of this case. The specific difference size is related to the starting position, ending position of the task, and the change law of rainfall over time. The experimental results confirm that the solution model of this case can reflect the continuous change of environmental rainfall and is more scientific and reasonable than the traditional environmental impact model.

[0056] Table 1 Difference between the predicted time of the static planning solution and the time evaluated in the model of this case when rainfall increases

[0057]

[0058]

[0059] Table 2 Difference between the predicted time of the static planning solution and the time evaluated in the model of this case when rainfall decreases

[0060]

[0061] Based on the above test data, it can be further illustrated that the comprehensive environmental impact model based on spatio-temporal voxels in the solution of this case can more scientifically and reasonably evaluate the comprehensive impact of the environment on the task, especially reflecting the impact of the continuous change of the environment over time. In fact, compared with the traditional space-based environmental impact model, the comprehensive environmental impact model based on spatio-temporal voxels in the solution of this case has many advantages, which is convenient for reasonably analyzing and evaluating the laws of the task affected by the environment and other factors, so as to accurately and comprehensively select the task execution plan, with high efficiency of task comprehensive environmental assessment and convenient for practical scenario application.

[0062] Based on the above system, an embodiment of the present invention further provides a server, including: one or more processors; a storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, enabling the one or more processors to implement the above method.

[0063] Based on the above system, an embodiment of the present invention further provides a computer-readable medium, on which a computer program is stored, wherein when the program is executed by a processor, the above method is implemented.

[0064] The device provided by the embodiment of the present invention has the same implementation principle and the same technical effects as those of the foregoing system embodiment. For the sake of brief description, for the parts not mentioned in the device embodiment, reference may be made to the corresponding content in the foregoing system embodiment.

[0065] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described system and device can refer to the corresponding processes in the foregoing system embodiment, and will not be elaborated herein.

[0066] In all the examples shown and described here, any specific value should be construed as merely exemplary, not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0067] It should be noted that similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0068] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, apparatuses, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a part of code that contains one or more executable instructions for implementing a specified logical function. It should also be noted that, in some alternative implementations, the functions noted in the blocks may occur in a different order than that noted in the accompanying drawings. For example, two consecutive blocks may actually be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as combinations of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system that performs the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0069] In several embodiments provided in this application, it should be understood that the disclosed systems, devices, and apparatuses can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical functional division, and there may be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings, direct couplings, or communication connections shown or discussed between each other can be through some communication interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0070] In addition, in each embodiment of the present invention, the functional units can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0071] If the described functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the systems described in various embodiments of the present invention. The aforementioned storage medium includes various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs.

[0072] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present invention, used to illustrate the technical solutions of the present invention, rather than limiting it. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the art within the technical scope disclosed by the present invention can still modify the technical solutions recorded in the foregoing embodiments or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels, characterized in that, It includes the following content: Construct a task-oriented spatio-temporal comprehensive environmental impact model for describing the laws of spatio-temporal environmental impact in the spatio-temporal coordinate system; the spatio-temporal comprehensive environmental impact model extends the time dimension on the basis of the spatial environmental cost law, and uses the spatio-temporal coordinate system to record the cumulative growth rate of the environmental cost during task execution due to environmental, situation, and ability factors of a spatial point over time points. Specifically, a three-dimensional rectangular coordinate system is established with a point on the ground surface as the origin, the eastward direction as the X-axis, the northward direction as the Y-axis, and time T as the Z-axis vertically upward, and this three-dimensional rectangular coordinate system is used as the spatio-temporal coordinate system; Respectively along the X-axis and Y-axis of the space-time coordinate system, the space is rasterized at the same spatial interval, and each spatial grid determines a spatial grid center; it is segmented along the T-axis at the same time interval, and the smallest space-time unit rasterized along the axes of the space-time coordinate system at the same spatial and time intervals is used as the space-time unit cube. The space-time unit cube is used as the space-time voxel for simplifying the complexity of environmental space changes and time changes. In the space-time coordinate system of the space-time comprehensive environmental impact model, the starting and reaching space-time coordinates of task execution are set, and the movement trajectory during the task execution process is regarded as several straight-line movements continuously passing through the corresponding space-time voxels. The space-time trajectory of the target task execution process is obtained based on the straight-line segments of the time points when entering and exiting the space-time voxel. The travel length and residence time within each space-time voxel passed by on the space-time trajectory are obtained by using the space-time coordinates of the space-time points when the task execution enters or exits the space-time voxel in the model. The comprehensive environmental cost of the task execution plan is obtained through the cost growth rate of each space-time voxel passed by on the space-time trajectory, the residence time within the corresponding space-time voxel, and the travel length. Among them, the cost generated by the task execution plan in the i-th space-time voxel is set Then the comprehensive environmental cost of the task execution plan is expressed as n represents the number of space-time voxels passed through by the space-time trajectory in sequence, represents the cost growth rate of the i-th space-time voxel, represents the residence time of the space-time trajectory in the i-th space-time voxel, represents the travel length of the space-time trajectory in the i-th space-time voxel.

2. The method for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels according to claim 1, characterized in that, In the spatio-temporal comprehensive environmental impact model, the total cost of the task execution plan is obtained by tracking the cost value corresponding to each spatio-temporal voxel passed through by the spatio-temporal trajectory during the task execution process, and the total cost value is used to evaluate the actual performance of the plan during task execution.

3. A system for comprehensively evaluating the environmental cost of a task plan based on spatio-temporal voxels, characterized in that, Implemented based on the method described in claim 1, including: a model construction module and a cost evaluation module, where, The model construction module is used to construct a task-oriented spatio-temporal comprehensive environmental impact model for describing the laws of spatio-temporal environmental impact in the spatio-temporal coordinate system; The cost evaluation module is used to rasterize the spatio-temporal comprehensive environmental impact model, divide the spatio-temporal into spatio-temporal unit cubes at the same spatial and time intervals along the axes of the spatio-temporal coordinate system, use the spatio-temporal unit cubes as spatio-temporal voxels, regard the task execution process as a series of continuous straight-line motions, obtain the spatio-temporal trajectory during the execution of the target task based on the spatio-temporal voxels and using trajectory tracking, and evaluate the comprehensive environmental cost of the target task plan according to the cost of the spatio-temporal voxels passed through by this spatio-temporal trajectory.

4. A computer-readable storage medium storing a computer program, when the computer program is executed by a processor, causing the processor to execute the steps of the method according to any one of claims 1 to 2.

5. A computer device comprising a memory and a processor, the memory storing a computer program, when the computer program is executed by the processor, causing the processor to execute the steps of the method according to any one of claims 1 to 2.

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