Automatic driving track forming method and system

Abstract

The invention relates to the technical field of road construction, in particular to an automatic driving track forming method and system.The system comprises a paver and a road roller, a left telescopic plate and a right telescopic plate are arranged on the two sides of the paver respectively, and the paver is in wireless connection with the road roller; in the advancing process of the paver, the pose information of the paver and the distance values between the geometric center of the paver and the left and right telescopic plates are obtained in real time; according to the pose information and the distance value of the paver, calculating to obtain a first driving track of the paver; and performing Gaussian smoothing processing on the first driving track to obtain a second driving track, processing the second driving track through a track fitting algorithm to obtain a target driving track, and finally sending the target driving track to the road roller, so that the road roller operates in a set operation plane according to the target driving track. According to the scheme, the road roller can automatically run according to the target running track to compact the current road surface, so that the road roller is more intelligent, and manpower is greatly saved.

Description

Technical Field

[0001] The present invention relates to the technical field of highway construction, and in particular to an automatic driving trajectory forming method and system. Background Art

[0002] During highway pavement construction, the paving and rolling of the water-stable layer and the asphalt layer is one of the most important links. The compaction and flatness of the construction pavement will directly affect the construction quality and driving comfort of the pavement. In normal manual paving and rolling operations, the operator drives the paver according to the road boundary pre-measured by the surveying and mapping personnel, and evenly spreads the concrete or asphalt material on the road surface to form a rolling operation surface; the roller group repeatedly drives and rolls on the operation surface, and finally forms a compacted and flat pavement that meets the construction quality requirements.

[0003] During the current construction process, pavers and rollers work independently. For example, an operator first operates the paver to lower and push the mixture. After completing this part of the operation, other operators drive the roller to further compact the spread mixture. The operation is relatively complicated and requires more manpower. In other words, the current road construction is highly dependent on labor. Pavers and rollers work independently without systematic control, resulting in low construction efficiency. Summary of the invention

[0004] The purpose of the present invention is to provide a method and system for forming an automatic driving trajectory, wherein an operator operates a paver to pave the mixture, and during the movement of the paver, data is automatically collected and processed to generate an automatic driving trajectory. A road roller can then automatically drive according to the automatic driving trajectory to further compact the paved mixture, making the operation simpler and more intelligent, thereby greatly saving manpower.

[0005] In order to achieve the above purpose, the technical solution adopted by the embodiment of the present invention is as follows:

[0006] In a first aspect, an embodiment of the present invention provides a method for forming an automatic driving trajectory, the method being applied to a paver, wherein left and right telescopic plates are respectively provided on both sides of the paver, and the paver is wirelessly connected to a road roller, the method comprising: acquiring in real time the posture information of the paver and the distance values ​​between the geometric center of the paver and the left and right telescopic plates during the movement of the paver; calculating a first driving trajectory of the paver based on the posture information of the paver and the distance values; performing Gaussian smoothing on the first driving trajectory to obtain a second driving trajectory; processing the second driving trajectory by a trajectory fitting algorithm to obtain a target driving trajectory; and sending the target driving trajectory to the road roller, so that the road roller operates within a predetermined working surface according to the target driving trajectory.

[0007] In the second aspect, an embodiment of the present invention further provides an automatic driving trajectory formation system, the system comprising a paver and a roller, the paver being provided with left and right telescopic plates on both sides, the paver being wirelessly connected to the roller; during the movement of the paver, the paver is used to obtain in real time the posture information of the paver and the distance values ​​between the geometric center of the paver and the left and right telescopic plates; the paver is also used to calculate a first driving trajectory of the paver based on the posture information of the paver and the distance values, and to perform Gaussian smoothing on the first driving trajectory to obtain a second driving trajectory, and to process the second driving trajectory through a trajectory fitting algorithm to obtain a target driving trajectory, and finally to send the target driving trajectory to the roller, so that the roller operates within a predetermined working surface according to the target driving trajectory.

[0008] An embodiment of the present invention provides an automatic driving trajectory formation method and system, the system includes a paver and a roller, the paver is provided with left and right telescopic plates on both sides, and the paver is wirelessly connected to the roller; during the movement of the paver, the position information of the paver and the distance values ​​between the geometric center of the paver and the left and right telescopic plates are obtained in real time; then, based on the position information and distance values ​​of the paver, a first driving trajectory of the paver is calculated; then, the first driving trajectory is Gaussian smoothed to obtain a second driving trajectory, the second driving trajectory is processed by a trajectory fitting algorithm to obtain a target driving trajectory, and finally, the target driving trajectory is sent to the roller, so that the roller operates within a predetermined working surface according to the target driving trajectory; it can be seen that this scheme automatically collects corresponding data during the movement of the paver and processes the data to obtain the target driving trajectory, so that the roller can automatically travel according to the target driving trajectory to further compact the current road surface after the paver completes the previous stage of operation, which is more intelligent and greatly saves manpower.

[0009] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 A schematic structural diagram of an automatic driving trajectory forming system provided by an embodiment of the present invention is shown.

[0012] Figure 2 A schematic diagram of a driving track of a paver provided by an embodiment of the present invention is shown.

[0013] Figure 3 A comparative schematic diagram of a driving trajectory of a paver provided by an embodiment of the present invention is shown.

[0014] Figure 4 A schematic diagram of a second driving trajectory of a paver provided by an embodiment of the present invention is shown.

[0015] Figure 5 A partially enlarged schematic diagram of a second travel trajectory of a paver provided by an embodiment of the present invention is shown.

[0016] Figure 6 A schematic diagram of a target driving trajectory of a paver provided by an embodiment of the present invention is shown.

[0017] Figure 7 A partially enlarged schematic diagram of a target driving trajectory of a paver provided by an embodiment of the present invention is shown.

[0018] Figure 8 A schematic flow chart of an automatic driving trajectory forming method provided by an embodiment of the present invention is shown.

[0019] Diagram:

[0020] 100-autonomous driving trajectory formation system; 110-paving machine; 120-road roller; 130-terminal equipment. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0022] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0023] During the construction of roads and bridges, the paving and rolling of the mixture is one of the most important links. The compaction and flatness of the construction road surface will directly affect the construction quality and driving comfort of the road surface. The mixture can be roughly classified into asphalt mixture and cement mixture. The highway pavement construction consists of three layers of cement mixture and three layers of asphalt mixture, a total of 6 layers; while tunnels and bridges are only paved with the top three layers of asphalt mixture. In normal manual paving and rolling operations, the operator drives the paver according to the road boundary pre-measured by the surveying and mapping personnel, and at the same time evenly spreads the mixture on the road surface and forms a rolling working surface. Then, the roller is repeatedly driven and rolled on the working surface under the driving of other operators, and finally forms a compacted and flat road surface that meets the construction quality requirements.

[0024] In view of the fact that in current construction operations, both pavers and rollers require manual operation and control by operators, the operation is complicated and consumes a lot of manpower. Therefore, an embodiment of the present invention provides an automatic driving trajectory formation system to control the paver and roller in a more intelligent way, thereby greatly saving manpower.

[0025] Please refer to Figure 1 , is a structural schematic diagram of an automatic driving trajectory formation system 100 provided in an embodiment of the present invention. The automatic driving trajectory formation system 100 includes a paver 110, a roller 120 and a terminal device 130. The paver 110 is provided with a wireless network router, an RTK (Real-Time Kinematic, real-time dynamic measurement technology) device, which is used to implement the measurement of posture information, a wireless bridge signal transmitting host, an automatic driving controller, and a laser rangefinder; the roller 120 is provided with an RTK device, a wireless bridge signal receiving host, a roller automatic driving controller and an obstacle avoidance millimeter wave; the terminal device 130 can be a handheld terminal, such as a tablet computer or a mobile phone, which can be wirelessly connected to the paver 110 and the roller 120 through the network to facilitate the sending of control commands. The paver 110 and the roller 120 can also be wirelessly connected through the wireless bridge signal transmitting host and the wireless bridge signal receiving host to facilitate the transmission of information to each other.

[0026] Furthermore, the paver 110 is a road construction equipment, which is mainly used for the laying of asphalt concrete or cement concrete pavements such as highways, municipal roads, airport runways, etc., and is intended to achieve uniform distribution, preliminary compaction and final leveling of materials. The core components of the paver 110 include a hopper, a scraper conveyor, a spiral distributor, a vibrating mechanism and a screed. The hopper is located at the front of the equipment and is used to receive hot asphalt mixture or concrete dumped by a transport vehicle; the scraper conveyor is located at the bottom of the hopper and is responsible for conveying the material backward to the middle part of the paver 110; then, the material is evenly distributed to the entire working width of the paver 110 through the spiral distributor, and the rotating action of the spiral distributor ensures the uniform distribution of the material, laying the foundation for subsequent paving work. The vibrating mechanism, including a vibrator or a vibrating screed, performs preliminary compaction of the material to improve the density and stability of the road surface, which is crucial to ensuring the uniformity of the road surface material and the final road surface quality. The screed plate is a key component of the paver, which performs the final compaction and leveling of the material through vibration and heating (in asphalt paving); the screed plate can adjust the angle and height to control the thickness and flatness of the paving layer to ensure that the road surface meets the design requirements. In addition, the paver 110 itself is equipped with an automatic driving controller to monitor the paving speed, material temperature and other key parameters to ensure the accuracy and efficiency of the construction process.

[0027] Furthermore, left and right telescopic plates are respectively provided on both sides of the paver 110. The left and right telescopic plates are part of the ironing plate and are used to adjust the paving width of the paver 110 to adapt to the construction requirements of road surfaces of different widths. That is to say, during the movement of the paver 110, as the edge of the paving section changes (the width changes), the operator will appropriately adjust the width of the left and right telescopic plates to ensure that the actual paved road surface is consistent with the planned paved road surface.

[0028] In addition, the RTK device installed on the paving machine 110 is a real-time differential GPS technology based on carrier phase observation. It can provide centimeter-level or even millimeter-level positioning accuracy in real time through the coordinated use of the base station and the mobile station. The base station is fixed at a known coordinate position, continuously observes satellites and sends the observation data to the mobile station in real time. The mobile station receives the signal from the GPS satellite and combines the data sent by the base station to calculate its own three-dimensional coordinates in real time.

[0029] In the autonomous driving trajectory forming system 100, the mobile station is the paver 110, which is specifically composed of two RTK positioning antennas and an IMU host. After the positioning antenna and the IMU host are installed on the paver 110, and the relative posture parameters between the antenna, the IMU host and the reference point of the paver 110 are correctly set, the RTK positioning technology can provide the paver 110 with 100Hz centimeter-level outdoor positioning data.

[0030] Furthermore, during the movement of the paver 110, the paver 110 obtains the position information of the paver 110 in real time at a predetermined frequency through the RTK device, and the position information includes the coordinate information and orientation information of the paver 110. For example, the RTK device can be set to report the position information of the paver 110 once every 0.01s, and the position information can be expressed as [x(i), y(i), θ(i), s(i)], i=1, 2, 3, ..., n, wherein x is the horizontal coordinate of the plane coordinate axis, y is the vertical coordinate of the plane coordinate axis, θ is the orientation information of the paver 110, s is the cumulative travel distance of the paver 110, which is obtained based on statistics of multiple horizontal coordinates and vertical coordinates, and n is the total number. In addition, laser rangefinders are installed on the inner sides of the left and right telescopic plates of the paver 110. The laser rangefinders are used to measure the distance between the geometric center of the paver 110 and the left and right telescopic plates in real time during the movement of the paver 110. The distance can be expressed as (l l , l r ), l l and l r They are the lengths from the geometric center of the paver 110 to the left and right telescopic plates, respectively. The geometric center of the paver 110 can be represented by the coordinate information (x(i), y(i)) collected by the above-mentioned RTK device.

[0031] Furthermore, the paver 110 is also used to calculate a first driving trajectory of the paver 110 according to the position information and distance value of the paver 110, specifically:

[0032] Please refer to Figure 2 , is a schematic diagram of a driving trajectory of a paver 110 provided by an embodiment of the present invention. During the driving process of the paver 110, multiple position information [x(i), y(i), θ(i), s(i)] collected by the RTK device, i = 1, 2, 3, ..., n, can be expressed as follows Figure 2 The dashed line in the figure, and the solid lines on both sides of the dashed line are the motion trajectories of the left and right telescopic plates on both sides of the paver 110 (left and right boundary coordinate sets). The motion trajectories of the left and right telescopic plates are mainly based on the coordinate information (x(i), y(i)) of the paver 110, the orientation information (θ(i)) and the distance value (l l and l r ) is calculated, and the calculation process can be expressed as:

[0033]

[0034] Then, through the motion trajectory (x l (i), y l (i))、(x r (i), y r(i)) The first driving trajectory of the paver 110 is calculated, that is, the midpoint of the motion trajectory of the left and right telescopic plates is taken to obtain the first driving trajectory of the paver 110, which can be expressed as:

[0035]

[0036] The first driving track of the paver 110 and the position information collected by the RTK positioning device can be simultaneously reflected in Figure 3 middle, Figure 3 : is a schematic diagram after the data is enlarged, in which the dotted line in the center represents the posture information, and the dotted line with irregular fluctuations around the dotted line is the calculated first driving trajectory of the paver 110. It can be seen that since the left and right telescopic plates of the paver 110 are often moved due to the influence of the environment and road conditions, there is a deviation between the actual first driving trajectory of the paver 110 and the trajectory formed by the reference posture information. The actual first driving trajectory has neither continuity nor derivability, and thus the first driving trajectory needs to be Gaussian smoothed.

[0037] That is, the first driving trajectory is subjected to Gaussian smoothing to obtain the second driving trajectory, which is specifically:

[0038] like Figure 3 As described above, the first driving trajectory as a whole fluctuates around the trajectory formed by the posture information, and only a few points deviate. The overall point set satisfies the characteristics of normal distribution. Therefore, the point set [x mid (i), y mid (i)] is Gaussian smoothing, that is, filtering the noise of the point set. Specifically, a first-order Gaussian is used to smooth the x mid (i), y mid (i) Smoothing is performed, which can be expressed as:

[0039]

[0040] Where σ is the standard deviation of the Gaussian distribution. After the standard deviation of the Gaussian distribution is determined, the internal weights of the Gaussian kernel are discretely assigned and normalized according to the Gaussian kernel window size 2n+1.

[0041] After the Gaussian kernel window size is determined, the discrete Gaussian kernel weight is calculated according to the Gaussian function:

[0042]

[0043] In order to improve the stability of the calculation, it is also necessary to normalize the weight matrices in the Gaussian kernel so that the total weight value in the Gaussian kernel is 1, avoiding numerical overflow or precision loss caused by the convolution kernel weight being too large or too small, which is expressed as:

[0044]

[0045] Finally, the Gaussian kernel matrix is ​​cross-multiplied with the point set matrix of the first driving trajectory to obtain the second driving trajectory after filtering and smoothing. Figure 4 As shown by the dotted line, Figure 5 Then Figure 4 The enlarged schematic diagram circled in the box shows that the second driving trajectory is roughly evenly distributed compared to the first driving trajectory. After multiple rounds of testing, it can be seen that when the Gaussian distribution standard deviation is set to 1.35 and the Gaussian kernel is set to 31, the smoothing effect can be optimal.

[0046] The second driving trajectory obtained by Gaussian filter processing has roughly met the vehicle trajectory requirements. However, in view of the process requirements and specifications of automatic driving in road construction, the continuity and smoothness of the filtered data still cannot fully meet the accuracy requirements, so it is necessary to continue to process the second driving trajectory through the trajectory fitting algorithm to obtain the final target driving trajectory. In an embodiment of the present invention, a trajectory fitting algorithm based on the least squares method is used to process the second driving trajectory, which is specifically:

[0047] First, define the circle equation as the curve fitting equation. Assuming that the coordinates of the center of the fitting circle are (A, B), the general formula of the circle equation is:

[0048] R 2 =(xA) 2 +(yB) 2 =(x 2 -2Ax+A 2 )+(y 2 -2By+B 2 )

[0049] Assume the simplified equation of the circle:

[0050] x 2 +y 2 +ax+by+c=0

[0051] Where a = -2A, b = -2B, c = A 2 +B 2 -R 2 .

[0052] Any point (x i ,y i ) to the center of the circle is:

[0053]

[0054] Therefore, any point (x i ,y i ) to the edge of the circle iThe difference between the sum of squares and the radius R square is:

[0055]

[0056] Based on the least squares method, the function Q(a, b, c) is established as the sum of the squares of Δd, and the simplified formula of the parallel circle equation is obtained:

[0057]

[0058] The optimal analytical solution of the parameters of the fitting circle equation is obtained by solving the partial differential of Q(a, b, c) and establishing a linear equation.

[0059]

[0060] Combining the above partial differential formulas, we get the linear equation:

[0061] AX=B

[0062]

[0063] And the parameter matrix is ​​calculated by matrix division Finally, the center coordinates (A, B) and radius R in the fitted circle equation are obtained:

[0064]

[0065] Finally, the target driving trajectory obtained by fitting the second driving trajectory is as follows Figure 6 As shown by the solid line in Figure 7 for Figure 6 The enlarged schematic diagram of the box part shows that after fitting, the continuity and smoothness of the target driving trajectory are better.

[0066] After the paver 110 calculates the target driving trajectory, it sends the target driving trajectory to the roller 120. After receiving the target driving trajectory, the roller 120 automatically drives the road surface according to the target driving trajectory to further compact the road surface. In addition, the relevant parameters of the paver 110 or the roller 120 can be synchronously transmitted to the terminal device 130, and the terminal device 130 can also send control commands to the paver 110 or the roller 120, such as the number of rolling passes, the rolling speed, etc.

[0067] It can be seen that the automatic driving trajectory forming system 100 provided by the embodiment of the present invention, by building an automatic driving system formed by a paver 110, a roller 120, and a terminal device 130, enables the paver 110 to automatically collect relevant data during driving, and obtain a target driving trajectory after processing the relevant data. Then, after the current operation stage is completed, the roller 120 can continue to perform compaction operations on the current road surface according to the generated target driving trajectory, which is more intelligent and greatly saves manpower and material resources.

[0068] Furthermore, an embodiment of the present invention also provides a method for forming an automatic driving trajectory, such as Figure 8 FIG. 1 is a schematic diagram of an automatic driving trajectory forming method provided by an embodiment of the present invention, the method comprising:

[0069] S110, acquiring in real time the position information of the paver and the distance values ​​between the geometric center of the paver and the left and right telescopic plates during the movement of the paver.

[0070] During the movement of the paver 110, the paver 110 obtains the position information of the paver 110 in real time at a predetermined frequency through the RTK device. The position information includes the coordinate information, orientation information and cumulative travel distance of the paver 110. For example, the RTK device can be set to report the position information of the paver 110 once every 0.01s. The position information can be expressed as [x(i), y(i), θ(i), s(i)], i=1, 2, 3, ..., n, where x is the horizontal coordinate of the plane coordinate axis, y is the longitudinal coordinate of the plane coordinate axis, θ is the orientation information of the paver 110, s is the cumulative travel distance of the paver 110, and n is the total number. In addition, a laser rangefinder is installed on the inner side of the left and right telescopic plates of the paver 110. The laser rangefinder is used to measure the distance between the geometric center of the paver 110 and the left and right telescopic plates in real time during the movement of the paver 110. It can be expressed as (l l , l r ), l l and l r They are the lengths from the geometric center of the paver 110 to the left and right telescopic plates, respectively. The geometric center of the paver 110 can be represented by the coordinate information (x(i), y(i)) collected by the above-mentioned RTK device.

[0071] S120: Calculate a first driving trajectory of the paver according to the position information of the paver and the distance value.

[0072] During the driving process of the paver 110, multiple position information [x(i), y(i), θ(i), s(i)] collected by the RTK device, i = 1, 2, 3, ..., n, can be expressed as follows Figure 2 The dashed line in the figure, and the solid lines on both sides of the dashed line are the motion trajectories of the left and right telescopic plates on both sides of the paver 110 (left and right boundary coordinate sets). The motion trajectories of the left and right telescopic plates are mainly based on the coordinate information (x(i), y(i)) of the paver 110, the orientation information (θ(i)) and the distance value (l l and l r ) is calculated, and the calculation process can be expressed as:

[0073]

[0074] Then, through the motion trajectory (x l (i), y l (i))、(x r (i), y r (i)) The first driving trajectory of the paver 110 is calculated, that is, the midpoint of the motion trajectory of the left and right telescopic plates is taken to obtain the first driving trajectory of the paver 110, which can be expressed as:

[0075]

[0076] S130: Perform Gaussian smoothing on the first driving trajectory to obtain a second driving trajectory.

[0077] Since the left and right telescopic plates of the paver 110 are often moved due to the influence of the environment and road conditions, there is a deviation between the actual first driving trajectory of the paver 110 and the trajectory formed by the reference posture information. The actual first driving trajectory is neither continuous nor derivable, and thus the first driving trajectory needs to be Gaussian smoothed.

[0078] Specifically, a first-order Gaussian is used to calculate x mid (i), y mid (i) Smoothing is performed, which can be expressed as:

[0079]

[0080] Where σ is the standard deviation of the Gaussian distribution. After the standard deviation of the Gaussian distribution is determined, the internal weights of the Gaussian kernel are discretely assigned and normalized according to the Gaussian kernel window size 2n+1.

[0081] After the Gaussian kernel window size is determined, the discrete Gaussian kernel weight is calculated according to the Gaussian function:

[0082]

[0083] In order to improve the stability of the calculation, it is also necessary to normalize the weight matrices in the Gaussian kernel so that the total weight value in the Gaussian kernel is 1, avoiding numerical overflow or precision loss caused by the convolution kernel weight being too large or too small, which is expressed as:

[0084]

[0085] Finally, the Gaussian kernel matrix is ​​cross-multiplied with the point set matrix of the first driving trajectory to obtain the second driving trajectory after filtering and smoothing. Figure 4 As shown by the dotted line, Figure 5 Then Figure 4 The enlarged schematic diagram circled in the box shows that the second driving trajectory is roughly evenly distributed compared to the first driving trajectory. After multiple rounds of testing, it can be seen that when the Gaussian distribution standard deviation is set to 1.35 and the Gaussian kernel is set to 31, the smoothing effect can be optimal.

[0086] S140: Process the second driving trajectory by using a trajectory fitting algorithm to obtain a target driving trajectory.

[0087] The second driving trajectory obtained by Gaussian filter processing has roughly met the vehicle trajectory requirements. However, in view of the process requirements and specifications of automatic driving in road construction, the continuity and smoothness of the filtered data still cannot fully meet the accuracy requirements, so it is necessary to continue to process the second driving trajectory through the trajectory fitting algorithm to obtain the final target driving trajectory. In an embodiment of the present invention, a trajectory fitting algorithm based on the least squares method is used to process the second driving trajectory, which is specifically:

[0088] First, define the circle equation as the curve fitting equation. Assuming that the coordinates of the center of the fitting circle are (A, B), the general formula of the circle equation is:

[0089] R 2 =(xA) 2 +(yB) 2 =(x 2 -2Ax+A 2 )+(y 2 -2By+B 2 )

[0090] Assume the simplified equation of the circle:

[0091] x 2 +y 2 +ax+by+c=0

[0092] Where a = -2A, b = -2B, c = A 2 +B 2 -R 2 .

[0093] Any point (x i ,y i ) to the center of the circle is:

[0094]

[0095] Therefore, any point (x i ,y i ) to the edge of the circle i The difference between the sum of squares and the radius R square is:

[0096]

[0097] Based on the least squares method, the function Q(a, b, c) is established as the sum of the squares of Δd, and the simplified formula of the parallel circle equation is obtained:

[0098]

[0099] The optimal analytical solution of the parameters of the fitting circle equation is obtained by solving the partial differential of Q(a, b, c) and establishing a linear equation.

[0100]

[0101] Combining the above partial differential formulas, we get the linear equation:

[0102] AX=B

[0103]

[0104] And the parameter matrix is ​​calculated by matrix division Finally, the center coordinates (A, B) and radius R in the fitted circle equation are obtained:

[0105]

[0106] Finally, the target driving trajectory obtained by fitting the second driving trajectory is as follows Figure 6 As shown by the solid line in Figure 7 for Figure 6 The enlarged schematic diagram of the middle circle part shows that after fitting, the continuity and smoothness of the target driving trajectory are better.

[0107] S150: Send the target driving trajectory to the roller, so that the roller operates within a predetermined working surface according to the target driving trajectory.

[0108] After the paver 110 calculates the target driving trajectory, it sends the target driving trajectory to the roller 120. After receiving the target driving trajectory, the roller 120 automatically drives the road surface according to the target driving trajectory to further compact the road surface. In addition, the relevant parameters of the paver 110 or the roller 120 can be synchronously transmitted to the terminal device 130, and the terminal device 130 can also send control commands to the paver 110 or the roller 120, such as the number of rolling passes, the rolling speed, etc.

[0109] In summary, an embodiment of the present invention provides an automatic driving trajectory formation method and system, the system includes a paver and a roller, the paver is provided with left and right telescopic plates on both sides, and the paver is wirelessly connected to the roller; during the movement of the paver, the position information of the paver and the distance values ​​between the geometric center of the paver and the left and right telescopic plates are obtained in real time; then, based on the position information and distance values ​​of the paver, a first driving trajectory of the paver is calculated; then, the first driving trajectory is Gaussian smoothed to obtain a second driving trajectory, the second driving trajectory is processed by a trajectory fitting algorithm to obtain a target driving trajectory, and finally, the target driving trajectory is sent to the roller, so that the roller operates in a predetermined working surface according to the target driving trajectory; it can be seen that this scheme automatically collects corresponding data during the movement of the paver and processes the data to obtain the target driving trajectory, so that the roller can automatically travel according to the target driving trajectory to further compact the current road surface after the paver completes the previous stage of operation, which is more intelligent and greatly saves manpower.

[0110] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0111] In addition, the functional modules in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0112] If the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention. It should be noted that similar numbers and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0114] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for forming an automatic driving trajectory, characterized in that: The method is applied to a paver, wherein left and right telescopic plates are respectively arranged on both sides of the paver, and the paver is wirelessly connected to a road roller, and the method comprises: During the movement of the paver, the position information of the paver and the distance values ​​between the geometric center of the paver and the left and right telescopic plates are obtained in real time; Calculating a first driving trajectory of the paver according to the position information of the paver and the distance value; Performing Gaussian smoothing on the first driving trajectory to obtain a second driving trajectory; Processing the second driving trajectory by a trajectory fitting algorithm to obtain a target driving trajectory; The target driving trajectory is sent to the roller, so that the roller operates within a predetermined working surface according to the target driving trajectory.

2. The method for forming an automatic driving trajectory according to claim 1, wherein: The step of obtaining the distance values ​​between the geometric center of the paver and the left and right telescopic plates in real time comprises: During the movement of the paver, the extension and retraction degree of the left and right retractable plates changes accordingly with the width of the road, and the real-time distance values ​​between the geometric center of the paver and the left and right retractable plates are respectively obtained in real time.

3. The method for forming an automatic driving trajectory according to claim 1, wherein: The step of obtaining the position information of the paver in real time comprises: During the movement of the paver, the coordinate information and orientation information of the paver are acquired in real time.

4. The method for forming an automatic driving trajectory according to claim 3, wherein: The step of calculating the first driving trajectory of the paver according to the posture information of the paver and the distance value comprises: According to the coordinate information, orientation information and distance value of the paver, a left and right boundary coordinate set corresponding to the left and right telescopic plates is calculated; The first driving trajectory of the paver is calculated based on the left and right boundary coordinate sets.

5. The method for forming an automatic driving trajectory according to claim 1, wherein: The step of processing the second driving trajectory by a trajectory fitting algorithm to obtain a target driving trajectory comprises: The second driving trajectory is processed using a trajectory fitting algorithm based on the least squares method to obtain a target driving trajectory.

6. The method for forming an automatic driving trajectory according to claim 1, wherein: The paver is also wirelessly connected to the terminal device. The paver receives and responds to the control command sent by the terminal device, wherein the control command includes the number of rolling passes and the rolling speed.

7. An automatic driving trajectory forming system, characterized in that: The system includes a paver and a roller, the paver is provided with left and right telescopic plates on both sides, and the paver is wirelessly connected to the roller; During the movement of the paver, the paver is used to obtain in real time the position information of the paver and the distance values ​​between the geometric center of the paver and the left and right telescopic plates; The paver is also used to calculate a first driving trajectory of the paver based on the posture information of the paver and the distance value, and perform Gaussian smoothing on the first driving trajectory to obtain a second driving trajectory, and process the second driving trajectory through a trajectory fitting algorithm to obtain a target driving trajectory, and finally send the target driving trajectory to the roller, so that the roller operates within a predetermined working surface according to the target driving trajectory.

8. The automatic driving trajectory forming system according to claim 7, characterized in that: The paver is provided with an RTK device, and the RTK device acquires the position information of the paver in real time at a predetermined frequency during the movement of the paver, wherein the position information includes the coordinate information and the orientation information of the paver.

9. The automatic driving trajectory forming system according to claim 7, characterized in that: Laser rangefinders are installed on the inner sides of the left and right telescopic plates of the paver. The laser rangefinders are used to measure the distance between the geometric center of the paver and the left and right telescopic plates in real time during the movement of the paver.

10. The automatic driving trajectory forming system according to claim 7, characterized in that: The automatic driving trajectory formation system also includes a terminal device, which is wirelessly connected to the paver, and the terminal device is used to send control commands to the paver, wherein the control commands include the number of rolling passes and the rolling speed.

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