A paving thickness control system and method for a paving machine

Abstract

The application discloses a paving thickness control system and method of a paver, and relates to the field of paving control.The system comprises a positioning module, an inclination sensor and a controller.The positioning module is used for collecting position information of the paver in real time; the inclination sensor is used for collecting the inclination angle of the paver in real time; and the controller is used for determining the inclination of the paver according to the inclination angle of the paver and the installation height of the positioning module, correcting the position information of the paver according to the inclination, calculating the corrected thickness according to the corrected position information and the design position information, and controlling the paving thickness of the paver according to the corrected thickness.The application can compensate for the posture change of the paver itself, and improve the control precision of the paving thickness.

Description

Technical Field

[0001] This application relates to the field of paving control, and in particular to a paver paving thickness control system and method. Background Technology

[0002] In the field of road construction, pavers are key construction equipment, and their paving quality directly affects the service life of roads and traffic safety. Paving thickness, as a core indicator for measuring paving quality, has always been an important goal pursued by the industry for precise control.

[0003] Currently, various technical solutions have emerged in the industry to achieve precise control of paving thickness. However, existing paving thickness control technologies still have many shortcomings. The paver itself tilts and vibrates during its movement, causing instability in its posture and resulting in uneven paving thickness, making it difficult to meet high-standard construction requirements. Summary of the Invention

[0004] The purpose of this application is to provide a paver paving thickness control system and method, which can compensate for changes in the paver's own posture and improve the control accuracy of paving thickness.

[0005] To achieve the above objectives, this application provides the following solution:

[0006] In a first aspect, this application provides a paver paving thickness control system, comprising:

[0007] The positioning module is used to collect the location information of the paver in real time;

[0008] Tilt sensor, used to collect the tilt angle of the paver in real time;

[0009] The controller is used to determine the tilt amount of the paver based on the paver's tilt angle and the installation height of the positioning module, correct the paver's position information based on the tilt amount, calculate the correction thickness based on the corrected position information and the design position information, and control the paving thickness of the paver based on the correction thickness.

[0010] In one embodiment, the positioning module includes two GPS receivers, which are respectively mounted on the two masts of the paver.

[0011] In one embodiment, the positioning module includes two receivers for the BeiDou Navigation Satellite System, which are respectively mounted on the two masts of the paver.

[0012] In one embodiment, the tilt sensor is disposed at the bottom of the paver screed.

[0013] In one embodiment, the controller is further configured to sequentially perform wavelet transform and Kalman filtering on the paver's tilt angle.

[0014] In one embodiment, the controller is further configured to correct the stroke of the paver's hydraulic cylinder according to the paver's tilt angle-hydraulic stroke mapping table; the tilt angle-hydraulic stroke mapping table is obtained in advance by calibrating the installation deviation of the tilt angle sensor using a total station.

[0015] In one embodiment, the paver paving thickness control system further includes: a laser rangefinder for measuring the pavement thickness after paving; the controller is also used to adjust the stroke of the paver hydraulic cylinder according to the pavement thickness.

[0016] In one embodiment, the paver paving thickness control system further includes: a multi-view vision sensor for acquiring multi-view images of the paver's travel direction and detecting position information of the paver's travel direction based on the multi-view images; the controller is also used to control the paver's travel path based on the position information of the paver's travel direction and the designed position information.

[0017] In one embodiment, the paver thickness control system further includes: an infrared thermal imager for real-time monitoring of the temperature distribution of the mixture inside the paver; the controller is also used to dynamically adjust the speed of the paver according to the temperature distribution of the mixture inside the paver.

[0018] Secondly, this application provides a method for controlling the paving thickness of a paver, including:

[0019] Real-time acquisition of paver location information and paver tilt angle;

[0020] The amount of inclination of the paver is determined based on the paver's tilt angle and the installation height of the positioning module;

[0021] The position information of the paver is corrected based on the tilt amount;

[0022] The corrected thickness is calculated based on the corrected location information and the design location information;

[0023] The paving thickness of the paver is controlled according to the corrected thickness.

[0024] According to the specific embodiments provided in this application, this application has the following technical effects:

[0025] This application provides a paver paving thickness control system and method. By collecting the paver's position information and tilt angle in real time, the paver's tilt amount is determined based on the paver's tilt angle and the installation height of the positioning module. The paver's position information is then corrected, and the corrected thickness is calculated based on the corrected position information and the design position information. This allows for control of the paver's paving thickness and enables real-time compensation for changes in the paver's posture, thereby improving the control accuracy of the paving thickness and enhancing the paving quality. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a paver paving thickness control system provided in an embodiment of this application.

[0028] Figure 2 This is a flowchart illustrating a method for controlling the paving thickness of a paver, as provided in an embodiment of this application. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] In one exemplary embodiment, such as Figure 1 As shown, a paver paving thickness control system is provided, including: a positioning module 101, an inclination sensor 102, and a controller 103.

[0032] The positioning module 101 is used to collect the location information of the paver 104 in real time. The location information of the paver 104 includes the x-axis coordinate (representing longitude), y-axis coordinate (representing latitude), and z-axis coordinate (representing elevation).

[0033] As an optional implementation, the positioning module 101 includes two GPS receivers, which are respectively mounted on the two masts of the paver 104. The positioning module 101 further integrates a Real-Time Kinematic (RTK) receiver.

[0034] As an alternative implementation, the positioning module 101 includes two receivers for the BeiDou Navigation Satellite System, which are respectively mounted on the two masts of the paver 104. Specifically, the BeiDou-3 navigation system is used.

[0035] The positioning module 101 of this application further integrates an Inertial Navigation System (INS), with a positioning accuracy of ±8mm in the horizontal direction and ±15mm in the vertical direction.

[0036] The tilt sensor 102 is used to collect the tilt angle of the paver 104 in real time. The tilt sensor 102 is installed on the bottom of the screed or on the frame of the paver 104.

[0037] As an optional implementation, there are multiple tilt sensors 102, each of which is a dual-axis digital tilt sensor. Multiple tilt sensors 102 form a multi-axis tilt sensing array with a measurement range of ±20° and a resolution of 0.001°.

[0038] As another optional implementation, there are two tilt sensors 102, namely a master tilt sensor and a slave tilt sensor. The two tilt sensors 102 are cross-validated, and a self-test program is triggered when the difference is greater than 0.1° to ensure the stability of tilt angle detection.

[0039] The controller 103 is used to determine the tilt amount of the paver 104 based on the tilt angle of the paver 104 and the installation height of the positioning module 101, correct the position information of the paver 104 based on the tilt amount, calculate the correction thickness based on the corrected position information and the design position information, and control the paving thickness of the paver 104 based on the correction thickness. The controller 103 is connected to the positioning module 101 and the tilt sensor 102 respectively, and can be installed in the cab of the paver 104.

[0040] In a specific application example, based on the tilt angle (including pitch and roll angle) of paver 104 and the installation height of positioning module 101, the tilt of paver 104's mast relative to the ground is calculated using the triangle theorem. The z-axis coordinate is then corrected based on the tilt. The corrected thickness is calculated using the corrected z-axis coordinate and the design height from the design position information. The angular deviation of paver 104 is considered when calculating the corrected thickness, thereby improving the control accuracy of the paving thickness.

[0041] To further improve the control accuracy of paving thickness, this application implements a hardware-level Precision Time Protocol (PTP). Through a satellite precision time synchronization system and pulse-per-second (PPS) signals, it aligns with the position information (10Hz) collected by the positioning module 101, the tilt angle (10Hz) collected by the tilt sensor 102, and the design position information (50Hz), among other frequency signals. Furthermore, a three-level transformation model is constructed, consisting of the BeiDou geodetic coordinate system → paver body coordinate system → screed tool coordinate system, integrating a tilt compensation matrix to achieve the construction and transformation of a dynamic coordinate system.

[0042] As an optional implementation, the controller 103 is implemented using an industrial-grade ARM+FPGA heterogeneous computing platform, supports EtherCAT bus, and has a real-time control cycle of 1ms.

[0043] As an optional implementation, the controller 103 adopts a nonlinear controller designed based on Lyapunov stability theory to solve the problem of strong coupling control under steep slope conditions.

[0044] The actuator of paver 104 includes an electro-hydraulic proportional valve assembly and a high-rigidity hydraulic lifting column. By controlling the actuator of paver 104, the attitude of the screed is adjusted, achieving a stroke resolution of 0.1 mm and a step response ≤80 ms for the hydraulic cylinder. The control model equation for the screed is:

[0045] ;

[0046] in, The ironing board needs to be adjusted in height. This is the proportionality coefficient. The integral coefficient is... These are the differential coefficients. To correct the thickness, t For time, The tilt angle, This is a hydraulic cylinder displacement command. f This is a function relating thickness and tilt angle to hydraulic cylinder displacement.

[0047] Furthermore, the controller 103 is also used to perform wavelet transform and Kalman filtering on the tilt angle of the paver 104 in sequence to eliminate vibration interference from the engine of the paver 104.

[0048] The controller 103 is also used to correct the stroke of the hydraulic cylinder of the paver 104 according to the tilt angle-hydraulic stroke mapping table of the paver 104. The tilt angle-hydraulic stroke mapping table is obtained in advance by calibrating the installation deviation of the tilt angle sensor 102 using a total station.

[0049] In another exemplary embodiment, the paver paving thickness control system further includes a laser rangefinder 105. The laser rangefinder 105 is used to measure the pavement thickness after paving. The laser rangefinder 105 is connected to a controller 103. The controller 103 is also used to adjust the stroke of the hydraulic cylinder of the paver 104 according to the pavement thickness. The accuracy of measuring the pavement thickness using the laser rangefinder 105 is ±0.5 mm.

[0050] In another exemplary embodiment, the paver paving thickness control system further includes a multi-view vision sensor 106. The multi-view vision sensor 106 is used to acquire multi-view images of the paver 104's travel direction and detect the position information of the paver 104's travel direction based on the multi-view images. The multi-view vision sensor 106 is connected to a controller 103. The controller 103 is also used to control the travel path of the paver 104 based on the position information of the paver 104's travel direction and the designed position information.

[0051] In another exemplary embodiment, the paver paving thickness control system further includes an infrared thermal imager 107. The infrared thermal imager 107 is used to monitor the temperature distribution of the mixture within the paver 104 in real time. The temperature detection resolution using the infrared thermal imager 107 is 0.5°C. The infrared thermal imager 107 is connected to a controller 103. The controller 103 is also used to dynamically adjust the speed of the paver 104 based on the temperature distribution of the mixture within the paver 104.

[0052] The main working process of the paver thickness control system provided in this application is as follows:

[0053] (1) Initialization calibration: The installation deviation of the tilt sensor 102 is calibrated using a total station, and a tilt angle-hydraulic stroke mapping table for the paver 104 is established. The hydraulic pressure marked on each hydraulic cylinder on each paver 104 is different. The tilt angle-hydraulic stroke mapping table is established in advance and can be used to correct the action of the hydraulic cylinder when controlling the paving thickness of the paver 104. The building information design model is loaded, and the design parameters of the road cross slope and longitudinal slope are extracted to obtain the design location information.

[0054] (2) Paving process control: The absolute position of the paver 104 is obtained through an RTK receiver, and the pitch and roll angles of the screed are fed back in real time by the tilt sensor 102. INS compensates for high-speed dynamic errors. The theoretical thickness is calculated based on the design position information and the tilt angle collected by the tilt sensor 102. The stroke of the hydraulic cylinder is adjusted through closed-loop feedback by the laser rangefinder 105. The three-dimensional coordinates in front of the paver 104 are automatically detected by the multi-view vision sensor 106, and the deviation is generated by comparing it with the design position information. The travel path of the paver 104 is automatically controlled. The temperature distribution of the mixture is monitored by the infrared thermal imager 107, and the paving speed is dynamically adjusted to ensure temperature uniformity (gradient ≤ 10℃ / m). The paved road surface is scanned by millimeter-wave radar to generate a smoothness cloud map and optimize the control parameters in reverse. ,in, This is for flatness error. These are the original control parameters. For the optimized control parameters, The learning rate is used to further establish a multi-dimensional database of tilt angle, thickness, and temperature, and train a long short-term memory network to predict the optimal combination of control parameters.

[0055] Building upon the aforementioned scheme, this application further proposes a coupled quantification method based on singular value decomposition to achieve independent optimization of thickness control and slope adjustment. When significant deviations occur in angle or position, such as signal obstruction, data from other sensors are used for detection. A virtual reference plane is calculated in real-time using data collected by the tilt sensor 102, replacing the traditional mechanical reference rope (reference beam) to adapt to complex curved surface paving. Furthermore, oil level sensors are installed in the hydraulic cylinders of multiple pavers 104, prioritizing the paver 104 with lower oil consumption for paving operations. This constructs a hydraulic system energy consumption model, reducing power consumption by 20%-30% while maintaining control accuracy.

[0056] As shown in Table 1, under different working conditions, the paver thickness control system provided in this application is superior to the traditional tilt angle mechanical control and pure positioning control system.

[0057] Table 1 Performance Comparison Results

[0058]

[0059] The paver paving thickness control system provided in this application can be applied in the following scenarios:

[0060] 1) Highways: Achieve a pavement thickness standard deviation of <1.5mm on road sections with a maximum longitudinal slope of 8%, improving accuracy by 300% compared to manual operation.

[0061] 2) Urban interchange ramps: Supports paving of small radius (30m) curves, with cross slope automatically following the design value (accuracy ±0.3%).

[0062] 3) Airport runway construction: meets FAA AC 150 / 5370-10B standards, with runway cross slope control accuracy reaching ±0.02%.

[0063] 4) 3D road surface printing: Combines tilt angle data to achieve one-time molding of irregular paving materials (such as speed bumps and road markings).

[0064] 5) Multi-machine collaborative operation: The master and slave pavers achieve synchronous leveling by sharing data collected by tilt sensors, eliminating overlap seam errors.

[0065] This application achieves sub-centimeter-level three-dimensional control of the paver through deep coupling of BeiDou / GPS positioning and tilt sensors. It compensates in real-time for the impact of paver pitch and roll angle changes on pavement thickness (slope adaptability ±15°), ensuring lateral deviation of the paving trajectory ≤3mm and longitudinal elevation deviation ≤2mm. Furthermore, the data from the tilt sensor and positioning module are fused, with a response delay ≤50ms. It maintains the stability of sensor data under vibration and temperature variations (-20℃~60℃) environments, overcoming the industry challenge of paving accuracy control in complex terrain and propelling road construction from a "geometry-driven" to a new paradigm of "physical-information fusion-driven."

[0066] Based on the same inventive concept, such as Figure 2 As shown in the figure, this application embodiment also provides a method for controlling the paving thickness of a paver, including the following steps 201 to 205.

[0067] Step 201: Collect the location information of the paver and the tilt angle of the paver in real time.

[0068] Step 202: Determine the tilt amount of the paver based on the paver's tilt angle and the installation height of the positioning module.

[0069] Step 203: Correct the position information of the paver based on the tilt amount.

[0070] Step 204: Calculate the corrected thickness based on the corrected location information and the design location information.

[0071] Step 205: Control the paving thickness of the paver according to the corrected thickness.

[0072] In summary, this application can accurately detect the tilt angle of the paver and compensate for the paver's posture in a timely manner, thereby effectively controlling the paving thickness and improving the paving quality. This technology should have advantages such as low cost, strong adaptability, and simple operation to meet the needs of different construction scenarios and promote the high-quality development of the road construction industry.

[0073] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0074] In this application, all actions to acquire signals, information, or data are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with the authorization granted by the owner of the relevant device.

[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A paver thickness control system, characterized in that, The paver thickness control system includes: The positioning module is used to collect the location information of the paver in real time; the location information of the paver includes the x-axis coordinate representing longitude, the y-axis coordinate representing latitude, and the z-axis coordinate representing elevation. The positioning module includes receivers for two Global Positioning Systems (GPS), which are respectively mounted on the two masts of the paver; the positioning module further integrates a Real-Time Differential (RTK) receiver. The positioning module also includes two receivers for the BeiDou satellite navigation system, which are respectively installed on the two masts of the paver, specifically using the BeiDou-3 navigation system. The positioning module further integrates a microelectromechanical inertial navigation system (INS), with a positioning accuracy of ±8mm in the horizontal direction and ±15mm in the vertical direction. An inclination sensor is used to collect the tilt angle of the paver in real time; the inclination sensor is installed on the bottom of the paver screed or on the frame. There are multiple tilt sensors, each of which is a dual-axis digital tilt sensor. The multiple tilt sensors form a multi-axis tilt sensing array with a measurement range of ±20° and a resolution of 0.001°. The controller is used to determine the paver's tilt angle and the installation height of the positioning module, correct the paver's position information based on the tilt angle, calculate the correction thickness based on the corrected position information and the design position information, and control the paver's paving thickness based on the correction thickness. Specifically, based on the paver's tilt angle and the installation height of the positioning module, the tilt angle between the paver mast and the ground is calculated using the triangle theorem; the z-axis coordinate is corrected based on the tilt angle; and the correction thickness is calculated based on the corrected z-axis coordinate and the design height in the design position information. By using the satellite precision timing system and the pulse per second (PPS) signal, the system aligns the 10Hz position information collected by the positioning module, the 10Hz tilt angle collected by the tilt sensor, and the 50Hz design position information, which are all different frequency signals. Furthermore, it constructs a three-level transformation model of the BeiDou geodetic coordinate system → paver body coordinate system → screed tool coordinate system, and integrates the tilt compensation matrix to realize the construction and transformation of the dynamic coordinate system. The paver's actuators include an electro-hydraulic proportional valve assembly and a high-rigidity hydraulic lifting column. By controlling the paver's actuators, the screed's posture is adjusted, achieving a hydraulic cylinder stroke resolution of 0.1 mm and a step response ≤80 ms. The control model equation for the screed is: Where ΔH is the required adjustment height of the ironing board, and K p K is the proportionality coefficient. i K is the integral coefficient. d e is the differential coefficient. h To correct for thickness, t is time, α real Let θ be the tilt angle. cmd is the hydraulic cylinder displacement command, and f is the relationship function between thickness, tilt angle and hydraulic cylinder displacement; The controller is also used to perform wavelet transform and Kalman filtering on the paver's tilt angle in sequence to eliminate vibration interference from the paver's engine. The controller is also used to correct the stroke of the paver's hydraulic cylinder according to the paver's tilt angle-hydraulic stroke mapping table; the tilt angle-hydraulic stroke mapping table is obtained in advance by calibrating the installation deviation of the tilt angle sensor using a total station; The controller adopts a nonlinear controller designed based on Lyapunov stability theory; A laser rangefinder is used to measure the pavement thickness after paving; the controller is also used to adjust the stroke of the paver's hydraulic cylinders according to the pavement thickness. A multi-view vision sensor is used to acquire multi-view images of the paver's travel direction and detect the paver's position information based on the multi-view images; the controller is also used to control the paver's travel path based on the paver's position information and the designed position information. An infrared thermal imager is used to monitor the temperature distribution of the mixture inside the paver in real time; the controller is also used to dynamically adjust the speed of the paver according to the temperature distribution of the mixture inside the paver. The working process of the paver's paving thickness control system is as follows: (1) Initialization calibration: The installation deviation of the tilt sensor is calibrated by a total station, and the tilt angle-hydraulic stroke mapping table of the paver is established; the hydraulic pressure marked on each hydraulic cylinder on each paver is different, and the tilt angle-hydraulic stroke mapping table is established in advance, which is used to correct the action of the hydraulic cylinder when controlling the paving thickness of the paver; the building information design model is loaded, the road cross slope and longitudinal slope design parameters are extracted, and the design location information is obtained; (2) Paving process control: The absolute position of the paver is obtained through an RTK receiver, and the pitch and roll angles of the screed are fed back in real time by an inclination sensor. INS compensates for high-speed dynamic errors. The theoretical thickness is calculated based on the design position information and the tilt angle collected by the inclination sensor. The stroke of the hydraulic cylinder is adjusted through closed-loop feedback of a laser rangefinder. The three-dimensional coordinates in front of the paver are automatically detected by a multi-view vision sensor, and the deviation is generated by comparing it with the design position information to automatically control the travel path of the paver. The temperature distribution of the mixture is monitored by an infrared thermal imager, and the paving speed is dynamically adjusted to ensure temperature uniformity with a gradient ≤10℃ / m. The paved road surface is scanned by millimeter-wave radar to generate a smoothness cloud map and optimize the control parameters in reverse. Where 'a' represents the flatness error. These are the original control parameters. The optimized control parameters are η, where η is the learning rate. A multi-dimensional database of tilt angle, thickness, and temperature is further established to train a long short-term memory network to predict the optimal combination of control parameters. Furthermore, a coupled quantification method based on singular value decomposition is proposed to achieve independent optimization of thickness control and slope adjustment. When there is a large deviation in angle or position, such as when the signal is blocked, data from other sensors is used for detection. A virtual reference plane is calculated in real time using data collected by tilt sensors to replace the traditional mechanical reference rope or reference beam, which can adapt to complex curved surface paving. Furthermore, oil volume sensors are installed in the hydraulic cylinders of multiple pavers to prioritize the pavers with low oil consumption for paving operations. A hydraulic system energy consumption model is constructed to reduce power consumption by 20%-30% while ensuring control accuracy. By deeply coupling BeiDou / GPS positioning with tilt sensors, sub-centimeter-level three-dimensional control of the paver is achieved, real-time compensation for the impact of changes in the paver's pitch and roll angles on the pavement thickness, and slope adaptability of ±15°, ensuring that the lateral deviation of the paving trajectory is ≤3mm and the longitudinal elevation deviation is ≤2mm. Furthermore, the data from the tilt sensor and the positioning module are integrated, with a response delay of ≤50ms, and the sensor data can maintain stability in environments with vibration and temperature changes ranging from -20℃ to 60℃.

2. A method for controlling the paving thickness of a paver, characterized in that, The paver paving thickness control system according to claim 1, wherein the paver paving thickness control method comprises: Real-time acquisition of paver location information and paver tilt angle; The amount of inclination of the paver is determined based on the paver's tilt angle and the installation height of the positioning module; The position information of the paver is corrected based on the tilt amount; The corrected thickness is calculated based on the corrected location information and the design location information; The paving thickness of the paver is controlled according to the corrected thickness.

Images