Paver screed control system and control method

Abstract

The application provides a paving machine screed control system and a control method. The paving machine screed control system comprises a plurality of first sensors, a plurality of second sensors, a plurality of hydraulic control devices and a controller. The plurality of first sensors are respectively arranged on two leveling oil cylinders, and the first sensors are used for monitoring the extension and retraction amount of the leveling oil cylinders in real time. The plurality of second sensors are respectively arranged on two lifting oil cylinders, and the second sensors are used for monitoring the extension and retraction amount of the lifting oil cylinders in real time. The plurality of hydraulic control devices are respectively connected with the leveling oil cylinders and the lifting oil cylinders. The controller is connected with the plurality of hydraulic control devices, the plurality of first sensors and the plurality of second sensors, and the controller is used for controlling the working state of the leveling oil cylinders and the lifting oil cylinders through the hydraulic control devices according to the extension and retraction amount of the leveling oil cylinders and the extension and retraction amount of the lifting oil cylinders, so as to adjust the screed to reach the preset parameters. The application solves the problem that the paving thickness and the screed angle of the paving machine cannot be accurately controlled in the prior art.

Description

Technical Field

[0001] This invention relates to the field of paver technology, and more specifically, to a paver screed control system and control method. Background Technology

[0002] Before paving operations, the screed height and starting elevation angle need to be set. Currently, this is done by placing sleepers of appropriate thickness. The actual starting paving thickness and screed elevation angle are mostly obtained through experience, which is a semi-manual operation. Even if tools are used for measurement, it is very inconvenient and cannot achieve a high degree of automation and convenience.

[0003] After paving operations begin, the thickness of the paving is usually determined on-site by measuring with steel rods and tape measures. This method can only measure the thickness at one point, which is time-consuming, labor-intensive, and has poor accuracy, allowing only a rough estimate of the paving thickness. There are now methods on the market that use the paver's balance beam to calculate the thickness, but this method requires the installation of a balance beam system on the outside of the paver, which is a large and expensive structure.

[0004] The appropriate and stable elevation angle of the paver during paving plays a crucial role in the smoothness of the paved surface. In essence, manufacturers' control of the screed is about dynamically balancing the elevation angle of the screed. An external leveling system adjusts the leveling cylinders before paving begins or at a specific point in time to achieve an elevation angle close to the operator's desired value. The paving thickness is set via the external leveling system, and a reference signal is fed back through contact between the leveling instrument and a curb or wire rope. This signal is used to adjust the leveling cylinders up and down, striving to approximate the initial reference value. However, the system doesn't actually know the exact elevation angle value, and neither does the operator. Therefore, both adjusting the elevation angle and improving the system's control precision are extremely challenging.

[0005] Both measuring thickness and leveling require the use of external devices or manual labor, which increases the difficulty of road paving and also increases the user's operating costs for the paver.

[0006] In terms of human-computer interaction, most pavers on the market do not have graphical reports on paving thickness or volume calculation summaries, nor do they display the elevation angle in real time, making it impossible for operators to grasp key information about paving elements.

[0007] Chinese patent CN 104141274A discloses a leveling system for a paver, the paver itself, and a leveling method. The method involves detecting a first height or first height deviation at the rear edge of the screed and a second height or second height deviation at the boom hinge point, and then adjusting the boom hinge point to eliminate the first or second height deviation. However, this patent cannot measure the real-time screed elevation angle.

[0008] Chinese patent CN 104195928A discloses a paver and its paving thickness identification device, system and method. By detecting the length of the lifting cylinder and calculating the angle between the lifting cylinder and the vertical plane, the height of the screed above the ground is calculated, thereby obtaining the paving thickness. However, this patent does not consider the influence of the screed elevation angle on the thickness, so the actual measurement effect will not be ideal.

[0009] Chinese patent CN 102337719A discloses a paver and its control method, control device, and control system. It uses a leveling instrument mounted behind the screed and a leveling instrument sensor arm to calculate the difference between the real-time value and the set value of the angle between the leveling instrument sensor arm and the vertical direction. Combined with the change in the leveling cylinder, the lifting cylinder is controlled to reduce this angle. This patent eliminates the difference in the angle between the leveling instrument sensor arm and the vertical direction by adjusting the lifting cylinder. However, this angle does not change significantly with changes in elevation angle and cannot be approximated as an elevation angle. Furthermore, this patent ignores the case where the roadbed is a slope. Also, this patent does not include the detection of paving thickness. Summary of the Invention

[0010] The main objective of this invention is to provide a paver screed control system and control method that can automatically and conveniently control the paving thickness and screed elevation angle of the paver, thereby at least solving the problem in the prior art that the paving thickness and screed elevation angle of the paver cannot be accurately controlled.

[0011] To achieve the above objectives, according to one aspect of the present invention, a paver screed control system is provided, comprising a screed, two traction arms, two leveling cylinders, two lifting cylinders, and two telescopic cylinders. The two leveling cylinders are respectively connected to the two traction arms, and the two lifting cylinders are also respectively connected to the two traction arms to drive the screed's movement. The two telescopic cylinders are respectively disposed at both ends inside the screed to drive the screed's movement. The control system further comprises a plurality of first sensors, a plurality of second sensors, a plurality of hydraulic control devices, and a controller. The plurality of first sensors are disposed on the leveling cylinders and are used to monitor the extension and retraction of the leveling cylinders in real time. The plurality of second sensors are disposed on the lifting cylinders and are used to monitor the extension and retraction of the lifting cylinders in real time. The plurality of hydraulic control devices are respectively connected to the leveling cylinders and the lifting cylinders. The controller is connected to the plurality of hydraulic control devices, the plurality of first sensors, and the plurality of second sensors. The controller is used to control the working state of the leveling cylinders and the lifting cylinders through the hydraulic control devices according to the extension and retraction of the leveling cylinders and the lifting cylinders to adjust the screed to achieve preset parameters. The preset parameters include the screed's elevation angle and the paving thickness.

[0012] Furthermore, the paver screed control system also includes multiple third sensors, which are respectively installed on the two telescopic cylinders. The third sensors are used to monitor the telescopic cylinder's extension and retraction in real time. The third sensors are connected to the controller, which is also used to calculate the paving volume of the screed based on the extension and retraction of the telescopic cylinder.

[0013] Furthermore, the first sensor, the second sensor, and the third sensor are all magnetostrictive sensors. The first sensor is located on the piston rod head of the leveling cylinder, the second sensor is located on the piston rod head of the lifting cylinder, and the third sensor is located on the piston rod head of the telescopic cylinder.

[0014] Furthermore, the control system also includes a display module, which is connected to the controller. The display module is used to display the extension and retraction of the leveling cylinder, the extension and retraction of the lifting cylinder, preset parameters, and paving volume collected by the controller.

[0015] Furthermore, the control system also includes a calibration module, a storage module, and an input module; the calibration module is connected to the controller and is used to calibrate the minimum extension and retraction of the leveling cylinder and the lifting cylinder, as well as the measured length of the leveling cylinder and the lifting cylinder when the ironing plate is in a level state; the storage module is connected to the controller and is used to store the minimum extension and retraction of the leveling cylinder and the lifting cylinder, as well as the measured length of the leveling cylinder and the lifting cylinder when the ironing plate is in a level state; the input module is connected to the controller and is used to input preset parameters to the controller.

[0016] According to another aspect of the present invention, a paver screed control method is provided. This method is applied to a paver screed control system and includes calibrating and storing the minimum extension / retraction amount of the leveling cylinder and the lifting cylinder to determine the extension / retraction lengths of the leveling cylinder and the lifting cylinder when the screed is in a level state; calculating preset extension / retraction amounts of the lifting cylinder and the leveling cylinder based on the extension / retraction lengths of the leveling cylinder and the lifting cylinder when the screed is in a level state, a preset paving thickness, and a preset screed elevation angle; driving the lifting cylinder to the preset extension / retraction amount and driving the leveling cylinder to the preset extension / retraction amount to bring the screed to a preset height and a preset elevation angle; maintaining the screed at the preset height and preset elevation angle and moving it along a preset path under the drive of the paver.

[0017] Furthermore, determining the extension lengths of the leveling cylinder and the lifting cylinder when the ironing board is in a level state includes placing the ironing board completely level on a flat, horizontal surface and calibrating that the ironing board is in a level state; receiving the measured lengths of the leveling cylinder and the lifting cylinder; and calculating the extension lengths of the leveling cylinder and the lifting cylinder based on the minimum extension amount of the leveling cylinder, the measured length of the leveling cylinder, the minimum extension amount of the lifting cylinder, and the measured length of the lifting cylinder.

[0018] Furthermore, the paver screed control method also includes sensing the undulation of the road surface, controlling the leveling cylinder according to the undulation of the road surface so that the extension and retraction of the leveling cylinder changes accordingly, and controlling the paving thickness and keeping the screed elevation angle constant according to the changing extension and retraction of the leveling cylinder.

[0019] Furthermore, the paver screed control method also includes real-time output display of paving thickness, screed elevation angle, and paving volume.

[0020] Furthermore, the real-time output displays the paving thickness, screed elevation angle, and paving volume, including a coordinate axis image output showing the trend of paving thickness as the paver moves and the paving distance changes.

[0021] The paver screed control system of this invention includes a screed, two traction arms, two leveling cylinders, two lifting cylinders, and two telescopic cylinders. The two leveling cylinders are connected to the two traction arms, and the two lifting cylinders are also connected to the two traction arms to drive the screed's movement. The two telescopic cylinders are respectively located at both ends inside the screed to drive its movement. The control system also includes multiple first sensors, multiple second sensors, multiple hydraulic control devices, and a controller. The multiple first sensors are located on the leveling cylinders and are used to monitor the extension and retraction of the leveling cylinders in real time. The multiple second sensors are located on the lifting cylinders and are used to monitor the extension and retraction of the lifting cylinders in real time. The multiple hydraulic control devices are respectively located on the leveling cylinders and the lifting cylinders. The controller is connected to the multiple hydraulic control devices, the multiple first sensors, and the multiple second sensors. The controller is used to adjust the screed to achieve preset parameters by controlling the working state of the leveling cylinders and the lifting cylinders through the hydraulic control devices based on the extension and retraction of the leveling cylinders and the lifting cylinders. The preset parameters include the screed's elevation angle and the paving thickness. The paver screed control system and control method provided by this invention can realize automated and convenient control of the paving thickness and screed elevation angle of the paver, solving the problem that the existing technology cannot accurately control the paving thickness and screed elevation angle of the paver. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0023] Figure 1 This is a structural block diagram of an optional paver screed control system according to an embodiment of the present invention;

[0024] Figure 2 This is a flowchart of an optional paver screed control method according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram showing the positional arrangement of the fixed points and hinge points on the paver in an optional paver screed control system according to an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram showing the connection between the fixed point and the hinge point of a paver screed control system, which is optional according to an embodiment of the present invention.

[0027] Figure 5 This is a schematic diagram showing the changing line relationship between the fixed point and the hinge point of a paver screed control system, which is optional according to an embodiment of the present invention.

[0028] Figure 6 This is a schematic diagram of the screed length relationship of an optional paver screed control system according to an embodiment of the present invention;

[0029] Figure 7 This is a schematic diagram showing the correspondence between the screed length and paving height of an optional paver screed control system according to an embodiment of the present invention;

[0030] Figure 8 This is a schematic diagram illustrating the variation trend of paving thickness with the paving distance of a paver, according to an optional paver screed control method based on an embodiment of the present invention.

[0031] The above figures include the following reference numerals:

[0032] 10. Leveling cylinder; 20. Lifting cylinder; 30. Telescopic cylinder; 40. Ironing plate; 50. First sensor; 60. Second sensor; 70. Hydraulic control device; 80. Controller; 90. Third sensor; 100. Display module; 110. Calibration module; 120. Storage module; 130. Input module. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] like Figure 1As shown, a paver screed control system includes a screed 40, two traction arms, two leveling cylinders 10, two lifting cylinders 20, and two telescopic cylinders 30. The two leveling cylinders 10 are connected to the two traction arms, and the two lifting cylinders 20 are also connected to the two traction arms to drive the screed 40. The two telescopic cylinders 30 are respectively located at both ends inside the screed 40 to drive its movement. The control system also includes multiple first sensors 50, multiple second sensors 60, multiple hydraulic control devices 70, and a controller 80. The multiple first sensors 50 are mounted on the leveling cylinders 10 and are used to monitor the leveling position in real time. The leveling cylinder 10 has a telescopic range; multiple second sensors 60 are mounted on the lifting cylinder 20, which are used to monitor the telescopic range of the lifting cylinder 20 in real time; multiple hydraulic control devices 70 are connected to the leveling cylinder 10 and the lifting cylinder 20 respectively; the controller 80 is connected to the multiple hydraulic control devices 70, multiple first sensors 50 and multiple second sensors 60, and the controller 80 is used to adjust the working state of the leveling cylinder 10 and the lifting cylinder 20 according to the telescopic range of the leveling cylinder 10 and the lifting cylinder 20 through the hydraulic control devices 70 to adjust the screed 40 to achieve preset parameters; wherein, the preset parameters include the screed elevation angle and the paving thickness. In use, this invention utilizes multiple first sensors 50 mounted on the leveling cylinder 10 to monitor its extension and retraction in real time, and multiple second sensors 60 mounted on the lifting cylinder 20 to monitor its extension and retraction in real time. Preset screed elevation angles and paving thicknesses are input to the controller 80. The controller 80, based on the extension and retraction of the leveling and lifting cylinders 10 and 20, uses a hydraulic control device 70 to control the working states of the leveling and lifting cylinders 10 and 20, thereby adjusting the screed 40 to achieve the preset screed elevation angle and paving thickness. During this process, the multiple first sensors 50 and multiple second sensors 60 continuously provide real-time feedback to achieve high-precision closed-loop control by the controller 80. The paver screed control system provided by this invention enables automated and convenient control of the paver's paving thickness and screed elevation angle, solving the problem of inaccurate control of these parameters in existing technologies. In addition to displacement sensors (such as magnetostrictive displacement sensors) inside the leveling cylinder and lifting cylinder, the telescopic ironing plate cylinder also contains a displacement sensor. The leveling cylinder, lifting cylinder, and telescopic ironing plate cylinder are arranged in pairs on the left and right. The cylinders have oil inlets and outlets, and are connected to the hydraulic valve group or hydraulic oil tank by hydraulic hoses. The cylinders are powered by the hydraulic control device 70, and the extension and retraction of the cylinders are changed by the opening degree of the corresponding valve block in the valve group.

[0035] Preferably, the hydraulic control device 70 is a proportional solenoid valve, which is mounted on a valve assembly installed inside the paver frame. The valve assembly is connected to the hydraulic cylinder via hydraulic hoses. The proportional solenoid valve precisely controls the cylinder's movement by controlling the opening of the corresponding valve block in the valve assembly. The controller 80 controls the proportional solenoid valve to ensure that the leveling cylinder 10 and the lifting cylinder 20 can move precisely, guaranteeing that the extension and retraction of the leveling cylinder 10 and the lifting cylinder 20 are sufficiently accurate.

[0036] As an optimized solution of the present invention, such as Figure 1 As shown, the paver screed control system also includes multiple third sensors 90, which are mounted on the telescopic cylinder 30. These third sensors 90 monitor the telescopic cylinder 30's extension and retraction in real time. The third sensors 90 are connected to a controller 80, which calculates the paving volume of the screed 40 based on the extension and retraction of the cylinder 30. Preferably, the third sensors 90 provide the controller 80 with the extension and retraction of the cylinder 30. This extension and retraction does not participate in or affect the controller 80's calculations of the paver's paving thickness and screed elevation angle. The extension and retraction of the cylinder 30 is used by the controller 80 to calculate the paver's paving width and paving volume. The controller 80 calculates the screed length or any possible lateral tilt angle of the screed based on the data provided by the third sensors 90, thereby calculating the paving volume. The total length of the screed 40, the length of the screed to the left of the left pivot point of the traction arm, and the length of the screed to the right of the right pivot point of the traction arm can be obtained by the extension and retraction of the telescopic cylinder 30. Combined with the two paving thickness values ​​of the screed, namely the height of the left pivot point and the right pivot point of the traction arm relative to the reference plane, the cross-sectional area of ​​the paving layer can be obtained, and the paving volume can be calculated.

[0037] As an optimized embodiment of the present invention, the first sensor 50, the second sensor 60, and the third sensor 90 are all magnetostrictive sensors. The first sensor 50 is disposed on the piston rod head of the leveling cylinder 10, the second sensor 60 is disposed on the piston rod head of the lifting cylinder 20, and the third sensor 90 is disposed on the piston rod head of the telescopic cylinder 30. Preferably, since the movable magnetic ring and the sensing element of the magnetostrictive sensor, which determine the position, do not have direct contact, the sensor can be used in extremely harsh industrial environments and is not easily affected by oil stains, solutions, dust, or other contaminants.

[0038] As an optimized solution of the present invention, the control system further includes a display module 100, which is connected to the controller 80. The display module 100 is used to display the extension and retraction of the leveling cylinder 10 and the lifting cylinder 20, as well as preset parameters, collected by the controller 80. The control system also includes a calibration module 110, a storage module 120, and an input module 130. The calibration module 110 is connected to the controller 80 and is used to calibrate the minimum extension and retraction of the leveling cylinder 10 and the lifting cylinder 20, and the measured lengths of the leveling cylinder 10 and the lifting cylinder 20 when the ironing board 40 is in a level state. The storage module 120 is connected to the controller 80 and is used to store the minimum extension and retraction of the leveling cylinder 10 and the lifting cylinder 20, and the measured lengths of the leveling cylinder 10 and the lifting cylinder 20 when the ironing board 40 is in a level state. The input module 130 is connected to the controller 80 and is used to input preset parameters to the controller 80. Preferably, as follows... Figure 1 As shown, the display module 100 is a monitor or human-machine interface, which is installed inside the paver's control panel and is independent. The calibration module 110, storage module 120, and input module 130 are integrated on the controller 80. The calibration module 110 is the process by which the controller 80 performs logical operations on the input signals. This process needs to be observed and operated on the monitor to achieve the calibration function. The storage module 120 is the process by which the storage unit inside the controller 80 stores data. The input module 130 is the input port built into the controller 80, which is presented in the form of a plug-in connector.

[0039] Preferably, the display interface, also known as the human-machine interface, has a working page, a calibration interface, and a volume measurement interface. The working page displays the calculated left paving thickness, right paving thickness, average paving thickness, left elevation angle, and right elevation angle. Under normal circumstances, the left and right leveling cylinders and lifting cylinders should move synchronously; otherwise, the screed's posture will be problematic, affecting the paving effect. Key displayed parameters are the average paving thickness, left elevation angle, and right elevation angle, and the elevation angles on both sides should be approximately the same. The calibration interface displays the real-time values ​​and zero-point calibration values ​​of the leveling cylinder, lifting cylinder, and screed telescopic cylinder, and allows for the calibration of the corresponding cylinders. The volume measurement interface displays the paving volume and paving distance. The controller 80 receives analog signals from the sensors using its input terminals, performs logical operations, executes calibration functions, stores parameters, and uses its output terminals to control the electro-proportional valve, thereby controlling the hydraulic system. The display is used for data display, parameter setting, calibration operation and other functions. The display communicates with the controller 80 through the CAN bus, sends the calibration function flag bit and the values ​​of each parameter to the controller 80, and receives the numerical data to be displayed after the controller 80 performs logical operations.

[0040] The following details the working principle of the controller 80 in calculating paving thickness, screed elevation angle, paving width, and paving volume.

[0041] like Figure 3 As shown, the fixing point between the lifting cylinder 20 and the frame is A; the fixing point between the leveling cylinder 10 and the frame is B; the leveling cylinder 10 and the traction arm are hinged together at point C; the lifting cylinder 20 and the traction arm are hinged together at point D; the lower rear edge of the ironing plate 40 is E; the angle between AB and BC is α; the angle between AC and CD is β; the angle between AC and CB is γ; the angle between BC and CB is δ; and the angle between CE and the horizontal direction is θ.

[0042] For any type of paver, once the frame is determined, the connecting line c between A and B is determined; the connecting line e between C and D on the traction arm is determined; the included angle α between AB and BC is determined; at the same time, the length a of the leveling cylinder 10 can be obtained from feedback by the first sensor 50, and the length d of the lifting cylinder 20 can be obtained from feedback by the second sensor 60.

[0043] Then the calculation formula for AC connection line b is:

[0044]

[0045] The formula for calculating the angle β between be and be is:

[0046] β=cos -1 ((b 2 +e 2 -d 2 ) / 2be)

[0047] The formula for calculating the included angle γ between ab is:

[0048] γ=cos -1 ((b 2 +a 2 -c 2 ) / 2ab)

[0049] The formula for calculating the included angle δ between ae and oe is:

[0050] δ=β+γ

[0051] If the δ angle value of the calibrated ironing plate 40 during leveling is δ0, and the ironing plate 40 and the traction arm are a rigid whole, then the line f connecting C and E has a definite value, and the angle θ between f and the bottom surface of the ironing plate 40 is a definite value. When the elevation angle of the ironing plate changes, it can be considered that the ironing plate 40 moves backward along E around the front hinge point C of the traction arm in an arc with a radius of f. Figure 4 As shown,

[0052] The rotation angle of f is the difference between δ and δ0, that is:

[0053] Δδ=δ-δ0

[0054] At the same time, such as Figure 4 As shown, according to the alternating interior angles in geometry, the angle of elevation of the ironing board is equal to Δδ, that is:

[0055] Ironing board elevation angle Δδ=δ-δ0

[0056] If the length of 'a' during the leveling of the calibrated ironing plate 40 is a0, then the change in leveling cylinder 10 is Δa = a0 - a. Figure 5 As shown, the following relationship exists:

[0057]

[0058] The above calculations refer to the screed elevation angle Δδ and paving thickness H obtained through calculations using a single-sided traction arm, screed 40, chassis, leveling cylinder 10, and lifting cylinder 20. Ideally, both sides should move synchronously, but due to the unevenness of the base road surface, there are certain differences between the two sides. Therefore, we assume that the paving thicknesses on both sides are H1 on the left and H2 on the right, respectively. Figure 6 and Figure 7 As shown, we have:

[0059] The thickness of the 40mm screed on the far left is H. 左 The 40mm screed has a paving thickness of H on the far right. 右 The length of the baseboard is L, and the length of the left telescopic ironing board is L. 左 The length L of the right telescopic ironing board 右 Left extension section length L 左加 Right extension section length L 右加 The average thickness is H 平均 The current paving cross-sectional area ΔS is calculated using the following formula based on the above data:

[0060]

[0061]

[0062]

[0063]

[0064] Let the speed be x, and the volume of asphalt material per unit time be ΔV = ΔS × x. Therefore, the formula for calculating the paving volume is as follows:

[0065]

[0066] The above process is the working principle of the controller 80 in calculating the paving thickness, screed elevation angle, paving width, and paving volume. By adding linear displacement sensors (such as hysteresis telescopic displacement sensors) to the leveling cylinder 10, lifting cylinder 20, and telescopic cylinder 30, the telescopic amount of the leveling cylinder 10, lifting cylinder 20, and telescopic cylinder 30 can be measured without changing the original structure of the paver.

[0067] Multiple first sensors 50 installed on the leveling cylinder 10 monitor the extension and retraction of the leveling cylinder 10 in real time, and multiple second sensors 60 installed on the lifting cylinder 20 monitor the extension and retraction of the lifting cylinder 20 in real time. The controller 80 can calculate the real-time screed elevation angle and paving thickness based on the extension and retraction of the leveling cylinder 10 and the lifting cylinder 20 according to the above process. The controller 80 controls the working state of the leveling cylinder 10 and the lifting cylinder 20 through the hydraulic control device 70 to adjust the screed 40 to achieve the preset screed elevation angle and paving thickness. When the controller 80 obtains the real-time value of the screed elevation angle, it precisely adjusts the extension and retraction of the leveling cylinder 10 through the proportional solenoid valve installed on the drive valve group to realize the real-time adjustment of the screed elevation angle, thereby achieving the stability of the screed elevation angle and ensuring the paving flatness.

[0068] Multiple third sensors 90 installed on the telescopic cylinder 30 monitor the telescopic cylinder 30's extension and retraction in real time. The controller 80 can calculate the paver's paving width and paving volume based on the extension and retraction of the telescopic cylinder 30 and display the results on the human-machine interface in real time.

[0069] like Figure 2 As shown, a paver screed control method is applied to a paver screed control system. The paver screed control method includes the following steps:

[0070] Step S102: Calibrate and store the minimum extension and retraction of the leveling cylinder 10 and the minimum extension and retraction of the lifting cylinder 20 to determine the extension and retraction lengths of the leveling cylinder 10 and the lifting cylinder 20 when the ironing board 40 is in a level state.

[0071] Step S104: Calculate the preset extension amount of the lifting cylinder 20 and the preset extension amount of the leveling cylinder 10 and the lifting cylinder 20 when the ironing board 40 is in a flat state, based on the preset spreading thickness and the preset ironing board elevation angle.

[0072] Step S106: Drive the lifting cylinder 20 to the preset extension amount and drive the leveling cylinder 10 to the preset extension amount so that the ironing board 40 is at the preset height and preset elevation angle;

[0073] Step S108: Keep the screed 40 at a preset height and preset elevation angle and move it along a preset path under the drive of the paver.

[0074] The controller 80 can calculate the paving thickness and screed elevation angle of the paver in real time based on the extension and retraction of the leveling cylinder 10 and the lifting cylinder 20. Simultaneously, it can calculate the preset extension and retraction of the lifting cylinder 20 and the leveling cylinder 10 based on preset paving thickness and preset screed elevation angle. The paver screed control method provided by this invention can effectively automate the screed preparation work before paver construction.

[0075] As an optimized solution of the present invention, the step S102 of determining the extension length of the leveling cylinder 10 and the extension length of the lifting cylinder 20 when the ironing plate 40 is in a level state includes placing the ironing plate 40 completely level on a flat, horizontal surface and calibrating the ironing plate 40 to be in a level state; receiving the measured lengths of the leveling cylinder 10 and the lifting cylinder 20; and calculating the extension lengths of the leveling cylinder 10 and the lifting cylinder 20 based on the minimum extension amount of the leveling cylinder 10, the measured length of the leveling cylinder 10, the minimum extension amount of the lifting cylinder 20, and the measured length of the lifting cylinder 20. The minimum extension amount of the leveling cylinder 10 and the minimum extension amount of the lifting cylinder 20 are used as the reference zero-point values ​​of the first sensor 50 and the second sensor 60, respectively. Under the condition that the processing accuracy is guaranteed, the minimum extension amount of each cylinder is constant. The above operation can eliminate the system error of the sensors themselves and the error caused by the sensor installation.

[0076] As an optimized solution of the present invention, the paver screed control method further includes sensing the undulation of the road surface and controlling the leveling cylinder 10 according to the undulation of the road surface so that the extension and retraction of the leveling cylinder 10 changes accordingly. The paving thickness is controlled based on the changing extension and retraction of the leveling cylinder 10, while maintaining a constant screed elevation angle. During normal construction, there are two scenarios: forced paving and floating paving. Forced paving can be used for road sections with high subgrade smoothness, short-distance paving, or sections where smoothness requirements are not high. Floating paving is used for longer paving distances or when the subgrade smoothness is not high. Forced paving involves locking the hydraulic cylinders up and down after completing the paving preparation state, making the screed, traction arm, and main unit a rigid whole. The screed is controlled at the ground height required for the initial paving thickness, and asphalt is applied through the rear edge of the screed. This paving method is highly dependent on the subgrade. Floating paving involves opening the lifting cylinders up and down after completing the paving preparation state, allowing the lifting cylinders to extend and retract freely. During paving operations, the main unit travels on the base course, dragging the screed floating in the material via the front hinge point of the traction boom. This creates a paving layer of a certain thickness beneath the screed; this is the process of floating paving. In the initial stages of floating paving, insufficient filler material beneath the screed often results in a thin initial paving layer. In this case, forced paving within the first ten meters or so yields better results. Furthermore, to prevent unevenness when resuming paving after a stop, the paver employs anti-climbing measures, essentially using forced paving followed by a few seconds of delay before switching to floating paving. During normal floating paving, when engine speed, paving speed, material gradation, and material temperature are relatively consistent, the elevation angle remains relatively constant, ensuring the paving thickness remains unchanged relative to the initial reference zero point, thus guaranteeing the smoothness of the paved surface. When the controller 80 obtains the real-time value of the ironing board's elevation angle, it precisely adjusts the extension and retraction of the leveling cylinder 10 through the proportional solenoid valve on the drive valve group to achieve real-time adjustment of the ironing board's elevation angle, thereby ensuring the stability of the ironing board's elevation angle and guaranteeing the flatness of the paving.

[0077] As an optimized solution of the present invention, such as Figure 8As shown, the paver screed control method also includes real-time output display of paving thickness, screed elevation angle, and paving volume. Real-time output display of paving thickness, screed elevation angle, and paving volume includes displaying the trend of paving thickness change with the paving distance traveled by the paver as a coordinate axis graph. Preferably, the paving record page of the human-machine interface displays a graphical average paving thickness, with the horizontal axis representing paving distance and the vertical axis representing paving thickness, thus intuitively showing the trend of paving thickness change and providing direct feedback to the operator or customer regarding problematic road sections. It can be seen that between 45m and 100m of paver travel, the paving thickness is almost linear, remaining at approximately 30mm. A slight increase in paving thickness around 60m indicates a possible road depression, while a slight decrease in paving thickness around 75m indicates a possible road bulge. Figure 8 You can see the road conditions directly.

[0078] The present invention provides:

[0079] 1. A method for determining the elevation angle, paving thickness, and paving width of the paver screed by using feedback signals from linear displacement sensors inside the paver screed lifting cylinder, leveling cylinder, and screed telescopic cylinder.

[0080] 2. A method for improving the paving smoothness of a paver by obtaining the elevation angle of the paver screed and adjusting the extension and retraction of the leveling cylinder solenoid valve in a closed-loop manner to ensure the stability of the screed elevation angle.

[0081] 3. A technical solution for an electrical system that acquires the screed elevation angle, paving thickness, and paving width of a paver, and is used to calibrate the paver's leveling zero position, display the elevation angle, paving thickness, paving width, paving volume, and average paving thickness charts, and provides closed-loop control of the leveling cylinder.

[0082] Advantages of the present invention:

[0083] 1. This technical solution provides a method for measuring paving thickness, screed elevation angle, and paving volume using a built-in linear displacement sensor without changing the original structure of the paver, thereby automating the preparation of the screed before paving.

[0084] 2. This technical solution provides a device for measuring paving thickness, screed elevation angle, and paving volume through sensors, controllers, and human-machine interface, as well as the control logic for realizing this function. The device monitors paving thickness, screed elevation angle, and paving volume in real time through the human-machine interface, and also reflects the changing trend of average paving thickness graphically in the human-machine interface.

[0085] 3. This technical solution provides a way to improve the stability of the screed elevation angle of the paver by obtaining the screed elevation angle value, thereby improving the paving smoothness without connecting external leveling instruments, balance beams, or other devices.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A paver screed control system, comprising a screed (40), two traction arms, two leveling cylinders (10), two lifting cylinders (20), and two telescopic cylinders (30), wherein the two leveling cylinders (10) are respectively connected to the two traction arms, and the two lifting cylinders (20) are respectively connected to the two traction arms to drive the screed (40) to move; and the two telescopic cylinders (30) are respectively disposed at both ends inside the screed (40) to drive the screed (40) to move, characterized in that, The control system further includes: Multiple first sensors (50) are respectively disposed on the two leveling cylinders (10), and the first sensors (50) are used to monitor the extension and retraction of the leveling cylinders (10) in real time; Multiple second sensors (60) are respectively disposed on the two lifting cylinders (20), and the second sensors (60) are used to monitor the extension and retraction of the lifting cylinders (20) in real time; Multiple hydraulic control devices (70) are connected to the leveling cylinder (10) and the lifting cylinder (20) respectively; The controller (80) is connected to multiple hydraulic control devices (70), multiple first sensors (50) and multiple second sensors (60). The controller (80) is used to control the working state of the leveling cylinder (10) and the lifting cylinder (20) through the hydraulic control devices (70) according to the extension and retraction of the leveling cylinder (10) and the lifting cylinder (20) to adjust the ironing board (40) to achieve preset parameters. The preset parameters include the screed elevation angle and the paving thickness; The control system further includes: A calibration module (110) is connected to the controller (80). The calibration module (110) is used to calibrate the minimum extension and retraction of the leveling cylinder (10) and the lifting cylinder (20) and the measurement length of the leveling cylinder (10) and the lifting cylinder (20) when the ironing plate (40) is in a flat state. Storage module (120), the storage module (120) is connected to the controller (80), the storage module (120) is used to store the minimum extension and retraction of the leveling cylinder (10) and the lifting cylinder (20) and the measured length of the leveling cylinder (10) and the lifting cylinder (20) when the ironing board (40) is in a flat state; An input module (130) is connected to the controller (80) and is used to input the preset parameters to the controller (80). The paver screed control system also includes: Multiple third sensors (90) are respectively disposed on two telescopic cylinders (30). The third sensors (90) are used to monitor the telescopic amount of the telescopic cylinders (30) in real time. The third sensors (90) are connected to the controller (80). The controller (80) is also used to calculate the paving volume of the screed (40) based on the telescopic amount of the telescopic cylinders (30). The formula for calculating the paving cross-sectional area is as follows: （1） In formula (1), because the unevenness of the base road surface causes a certain difference between the two sides, the paving thicknesses on the two sides are set as H1 on the left and H2 on the right, respectively; the paving thickness of the leftmost side of the screed (40) is H. 左 The screed (40) has a paving thickness of H on the far right. 右 The length of the baseboard is L, and the length of the left telescopic ironing board is L. 左 The length L of the right telescopic ironing board 右 Left extension section length L 左加 Right extension section length L 右加 The current paving cross-sectional area ΔS; The paving speed is x, and the volume of asphalt material per unit time is x. The paving volume V is calculated according to the following formula: （2）。 2. The paver screed control system according to claim 1, characterized in that, The first sensor (50), the second sensor (60) and the third sensor (90) are all magnetostrictive sensors. The first sensor (50) is located on the piston rod of the leveling cylinder (10), the second sensor (60) is located on the piston rod of the lifting cylinder (20), and the third sensor (90) is located on the piston rod of the telescopic cylinder (30).

3. The paver screed control system according to claim 1, characterized in that, The control system further includes: The display module (100) is connected to the controller (80) and is used to display in real time the extension and retraction of the leveling cylinder (10), the extension and retraction of the lifting cylinder (20), the preset parameters and the paving volume collected by the controller (80).

4. A paver screed control method based on the paver screed control system according to any one of claims 1 to 3, the paver screed control method comprising: The minimum extension and retraction of the leveling cylinder (10) and the minimum extension and retraction of the lifting cylinder (20) are calibrated and stored to determine the extension and retraction lengths of the leveling cylinder (10) and the lifting cylinder (20) when the ironing board (40) is in a flat state. The preset extension and retraction of the lifting cylinder (20) and the preset extension and retraction of the leveling cylinder (10) are calculated based on the extension and retraction length of the leveling cylinder (10) and the lifting cylinder (20) when the ironing plate (40) is in a flat state, the preset paving thickness and the preset elevation angle of the ironing plate. Drive the lifting cylinder (20) to the preset extension amount and drive the leveling cylinder (10) to the preset extension amount so that the ironing board (40) is at a preset height and preset elevation angle; The screed (40) is kept at a preset height and preset elevation angle and moves along a preset path under the drive of the paver.

5. The paver screed control method according to claim 4, characterized in that, The extension lengths of the leveling cylinder (10) and the lifting cylinder (20) when the ironing board (40) is determined to be in a level state include: Place the ironing board (40) completely flat on a level, flat surface and mark the ironing board (40) as being in a flat state; Receive the measured length of the leveling cylinder (10) and the measured length of the lifting cylinder (20); The extension length of the leveling cylinder (10) and the extension length of the lifting cylinder (20) are calculated based on the minimum extension amount of the leveling cylinder (10), the measured length of the leveling cylinder (10), the minimum extension amount of the lifting cylinder (20), and the measured length of the lifting cylinder (20).

6. The paver screed control method according to claim 4, characterized in that, The paver screed control method also includes: The system senses the undulation of the road surface and controls the leveling cylinder (10) according to the undulation of the road surface so that the extension and retraction of the leveling cylinder (10) changes accordingly. The system controls the paving thickness and keeps the screed elevation angle unchanged according to the changing extension and retraction of the leveling cylinder (10).

7. The paver screed control method according to claim 6, characterized in that, The paver screed control method also includes: The real-time output displays the paving thickness, the screed elevation angle, and the paving volume.

8. The paver screed control method according to claim 7, characterized in that, The real-time output displays the paving thickness, the screed elevation angle, and the paving volume, including a coordinate axis image output showing the trend of the paving thickness as the paver moves and paves.

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