Control method and apparatus for road roller

Abstract

The present invention relates to the technical field of vibratory road roller control. Disclosed are a control method and apparatus for a road roller, aiming to solve the technical problem of difficulty in determining an abnormal working state during a vibratory compaction operation and performing protective shutdown. The method comprises: acquiring a second-order system natural frequency value between a road roller and a soil layer, and in response to the second-order system natural frequency value reaching a first threshold, stopping a vibratory compaction operation; acquiring an actual vibration frequency value of the road roller, and in response to the actual vibration frequency value being less than a second threshold, stopping the vibratory compaction operation; and acquiring a compaction degree value of the soil layer, and in response to the compaction degree value being greater than a third threshold value, stopping the vibratory compaction operation. Determination of an abnormal working state is performed for the entire process of the vibratory compaction operation of the road roller, and the vibratory compaction operation is protectively stopped, so as to prevent the road roller from excessively compacting the fully compacted soil layer, prevent an ineffective operation with uncontrollable quality, and prevent the road roller from continuing to vibrate and cause damage after driving onto the compacted soil layer during normal vibratory compaction operation.

Description

A control method and device for a road roller Technical Field

[0001] This invention relates to a control method and device for a road roller, belonging to the field of vibratory road roller control technology. Background Technology

[0002] Commonly used methods for detecting and controlling soil compaction, including the sand cone method, bearing plate method, and falling ball method, typically only provide the compaction degree at the sampling point, not the overall compaction degree of the soil layer. Furthermore, all of these methods are implemented after vibratory compaction. However, it is difficult to ascertain the compaction state of the soil layer during vibratory compaction operations. This can lead to insufficient compaction or continued compaction on already compacted layers, resulting in damage to the already compacted layers. Existing road rollers struggle to identify abnormal compaction conditions and take appropriate measures after stopping operations.

[0003] In summary, existing control methods for road rollers are unable to effectively identify abnormal working conditions and take protective measures to stop operation during vibration compaction. Summary of the Invention

[0004] The purpose of this application is to overcome the shortcomings of the prior art and provide a control method and device for a road roller that can identify abnormal working conditions and protect the roller from stopping during vibration compaction operations.

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

[0006] Firstly, this application provides a control method for a road roller, including...

[0007] The second-order natural frequency value of the system between the roller and the soil layer is obtained, and the vibration compaction operation is stopped when the second-order natural frequency value reaches the first threshold.

[0008] The actual vibration frequency value of the road roller is obtained, and the vibration compaction operation is stopped in response to the actual vibration frequency value being less than a second threshold.

[0009] Obtain the compaction degree value of the soil layer, and stop the vibration compaction operation in response to the compaction degree value being greater than a third threshold.

[0010] In some embodiments of the first aspect, obtaining the second-order natural frequency value of the system between the roller and the soil layer includes,

[0011] The vibration acceleration of the road roller is obtained, and acceleration data is acquired within a set time period starting from when the vibration acceleration is zero;

[0012] After zero-padding the acceleration data, a Fourier transform is performed to obtain the acceleration amplitude-frequency data;

[0013] Find the frequency corresponding to the maximum amplitude from the acceleration amplitude-frequency data, and calculate the displacement amplitude at the frequency corresponding to the maximum amplitude.

[0014] Starting from the frequency corresponding to the maximum amplitude, the data is shifted, and the displacement amplitude of the frequencies at adjacent positions is calculated;

[0015] Find the maximum displacement amplitude from multiple displacement amplitudes, and use the frequency corresponding to the maximum displacement amplitude as the second-order natural frequency value of the system between the road roller and the soil layer.

[0016] In some embodiments of the first aspect, the road roller is a single-drum vibratory road roller, the first threshold value ranges from 17 to 22 Hz, and the second threshold value ranges from 23 to 25 Hz.

[0017] In some embodiments of the first aspect,

[0018] The vibration acceleration of the road roller is obtained, and the actual vibration frequency is obtained based on the vibration acceleration.

[0019] In some embodiments of the first aspect, the second threshold is calculated by multiplying the preset excitation frequency of the roller by a fixed coefficient.

[0020] In some embodiments of the first aspect, obtaining the compaction degree value of the soil layer includes,

[0021] The vibration acceleration of the road roller is obtained, and the acceleration data is zero-padded and then subjected to Fourier transform to obtain the acceleration amplitude-frequency data.

[0022] The 0.5 harmonic frequency domain amplitude and the fundamental frequency domain amplitude are extracted from the acceleration amplitude-frequency data;

[0023] The compaction degree value is calculated using the following formula:

[0024] In the formula, ST3 is the compaction degree value of the soil layer, and A 0.5 A is the frequency domain amplitude at 0.5 times the frequency. 基 R is the fundamental frequency domain amplitude. c This is the magnification factor.

[0025] Secondly, this application also provides a control device for a road roller, including,

[0026] The controller is used to acquire the second-order natural frequency value of the system between the roller and the soil layer, and to stop the vibration compaction operation in response to the second-order natural frequency value reaching a first threshold.

[0027] The actual vibration frequency value of the road roller is obtained, and the vibration compaction operation is stopped in response to the actual vibration frequency value being less than a second threshold.

[0028] Obtain the compaction degree value of the soil layer, and stop the vibration compaction operation in response to the compaction degree value being greater than a third threshold;

[0029] An acceleration sensor, electrically connected to the controller, is used to acquire the vibration acceleration of the road roller; the controller acquires the second-order natural frequency value of the system between the road roller and the soil layer, the actual vibration frequency value of the road roller, and the compaction degree value of the soil layer based on the vibration acceleration.

[0030] Thirdly, this application also provides a computer device, including a processor and a memory connected to the processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, it performs the steps of the control method for a road roller as described in any embodiment of the first aspect.

[0031] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the control method for the road roller described in any embodiment of the first aspect.

[0032] Fifthly, this application also provides a computer program product, including a computer program / instructions, characterized in that, when the computer program / instructions are executed by a processor, they implement the steps of the control method for the road roller described in any embodiment of the first aspect.

[0033] Compared with the prior art, the beneficial effects achieved by this application are as follows:

[0034] The control method and device for the road roller provided in this application can identify abnormal working conditions throughout the entire process of the road roller's vibration compaction operation and protectively stop the vibration compaction operation. It can identify the compaction state of the soil layer to prevent the road roller from over-compacting the already fully compacted soil layer, and can identify the vibration compaction capacity of the road roller to prevent ineffective operation with uncontrollable quality. During normal vibration compaction operation, it can prevent the road roller from continuing to vibrate and damage the already compacted soil layer after entering it, based on the compaction degree value of the soil layer. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0036] Figure 1 is a flowchart of the control method for the road roller provided in this embodiment;

[0037] Figure 2 is a schematic diagram of the control device for the road roller provided in this embodiment;

[0038] Figure 3 is a schematic block diagram of the computer device provided in this embodiment;

[0039] In the diagram: 1. Controller; 2. Accelerometer. Detailed Implementation

[0040] It should be noted that "vibration acceleration" is sometimes abbreviated as "acceleration".

[0041] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other.

[0042] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0043] Example 1:

[0044] Figure 1 is a flowchart of a control method for a road roller according to Embodiment 1 of the present invention. This flowchart only shows the logical sequence of the method described in this embodiment. Under the premise of no conflict, in other possible embodiments of the present invention, the steps shown or described may be performed in a different order than that shown in Figure 1.

[0045] The control method for a road roller provided in this embodiment can be applied to the control module of a road roller. Referring to Figure 1, the method of this embodiment specifically includes the following steps:

[0046] First, the second-order natural frequency value between the roller and the soil layer is obtained. When the second-order natural frequency value reaches a first threshold, it indicates that the soil layer being compacted by the roller is sufficiently dense to meet design requirements. Vibration compaction should then be stopped to prevent further compaction on the already compacted layer, which could damage it. It is worth noting that this judgment step is primarily executed during the roller's initial vibration phase, and the execution time depends on the time it takes for the roller to reach its resonant frequency. For example, if a typical roller takes 3 seconds to reach its resonant frequency, the execution time for this judgment step is 3.512 seconds, ensuring that the second-order natural frequency value between the roller and the soil layer can be collected during the initial vibration phase.

[0047] Within a certain range, the soil layer follows the rule that the denser the soil layer, the higher the resonance frequency. Therefore, ideally, the resonance frequency between the roller and the soil layer should be obtained and compared with a set first threshold. When the resonance frequency is lower than the first threshold, it means that the soil layer being worked on by the roller is not compacted properly and needs to be compacted by vibration. When the resonance frequency reaches the first threshold, it means that the soil layer is compacted properly and work needs to be stopped to prevent the soil layer from being damaged by vibration.

[0048] However, the resonant frequency between the roller and the soil layer is difficult to measure directly in the actual construction environment. Therefore, this embodiment uses the second-order system natural frequency value between the roller and the soil layer, which is similar in value, to replace the resonant frequency between the roller and the soil layer. The second-order system natural frequency between the roller and the soil layer can be obtained directly or indirectly by installing sensors on the roller, which is more convenient and greatly improves the engineering implementation possibility of this method. This ensures that abnormal working conditions can be identified and protective shutdown can be carried out when the roller is in the vibration stage.

[0049] Those skilled in the art will readily recognize that the first threshold is set based on the soil compaction design and the roller model. Specific methods for obtaining this threshold can be found through experiments, computer simulations, or empirical values.

[0050] Secondly, the actual vibration frequency value of the road roller is obtained. In response to the actual vibration frequency value being less than the second threshold, the vibration compaction operation is stopped. This step is mainly performed after confirming that the soil layer has not been sufficiently vibrated and compacted, and its purpose is to verify the vibration compaction capability of the road roller.

[0051] If the actual vibration frequency value reaches the second threshold, it means that the vibration compaction capacity of the road roller can meet the vibration compaction requirements of the soil layer with that thickness, and normal vibration compaction operation can begin. However, if the actual vibration frequency value is less than the second threshold, it means that the vibration compaction capacity of the road roller cannot meet the vibration compaction requirements of the soil layer with that thickness, and the road roller is performing ineffective compaction. Under this state, the compaction quality is uncontrollable. Therefore, it is necessary to take measures after the road roller stops working, so as to promptly identify the abnormal vibration compaction operation state and take protective shutdown measures.

[0052] Finally, the compaction degree value of the soil layer is obtained, and the vibration compaction operation is stopped when the compaction degree value is greater than the third threshold. While the road roller is vibrating and compacting, it is difficult to distinguish between compacted and uncompacted soil layers with the naked eye. The driver may unknowingly drive onto the compacted soil layer, causing the compacted soil layer to be damaged by vibration. The significance of this step is that after entering the normal vibration compaction operation, if the road roller drives onto the compacted soil layer, the compaction degree value can be used to determine that it has driven onto the compacted soil layer, and then the vibration compaction operation can be stopped to prevent the compacted soil layer from being damaged.

[0053] Obtaining the compaction degree value of the soil layer can be achieved in other forms known in the art, which will not be elaborated here. The third threshold can be obtained based on the compaction design parameters of the soil layer, or by measuring the compaction degree value of the compacted soil layer on site.

[0054] The method of stopping vibration compaction can be implemented in other forms known in the art. For example, if the control method of the roller provided in this embodiment is deployed on the roller's VCU, the vibration compaction can be stopped by issuing a command to cut off the power of the vibratory wheel; or, if the control method of the roller provided in this embodiment is deployed on the instrument panel, the driver can be reminded to stop the vibration compaction by issuing a warning on the instrument panel; and many other known forms, which will not be described in detail here.

[0055] The control method for the road roller provided in this embodiment identifies abnormal working states throughout the entire process of the road roller's vibratory compaction operation and protectively stops the vibratory compaction operation. It can identify the compaction state of the soil layer to prevent the road roller from over-compacting the already fully compacted soil layer, and can identify the vibratory compaction capacity of the road roller to prevent ineffective operations with uncontrollable quality. During normal vibratory compaction operations, it can prevent the road roller from continuing to vibrate and damage the already compacted soil layer after entering it, based on the degree of compaction of the soil layer.

[0056] Example 2:

[0057] This embodiment provides a control method for a road roller. This embodiment is an optimization based on Embodiment 1 to improve the technical effect and refine the technical solution. For details not described in this embodiment, please refer to Embodiment 1.

[0058] Example 1 mentions using the second-order natural frequency of the system between the roller and the soil layer to replace the resonant frequency between the roller and the soil layer. As one embodiment, obtaining the second-order natural frequency of the system between the roller and the soil layer includes: acquiring the vibration acceleration of the roller; acquiring acceleration data within a set time period starting from zero vibration acceleration; performing a Fourier transform on the acceleration data after zero-padding to obtain acceleration amplitude-frequency data; finding the frequency corresponding to the maximum amplitude from the acceleration amplitude-frequency data, and calculating the displacement amplitude at the frequency corresponding to the maximum amplitude; shifting the data starting from the frequency corresponding to the maximum amplitude, and calculating the displacement amplitude at adjacent frequencies; finding the maximum displacement amplitude from multiple displacement amplitudes, and using the frequency corresponding to the maximum displacement amplitude as the second-order natural frequency of the system between the roller and the soil layer.

[0059] In this process, acceleration data is acquired within a set time period starting from zero vibration acceleration. This set time period is generally the longest theoretical or empirically estimated time for resonance to occur between the roller and the soil layer. As one embodiment, the vibration frequency of the roller's vibratory wheel gradually increases within the set time period, traversing all vibration frequencies starting from 0Hz. The roller's vibration acceleration is collected by sensors, and the maximum displacement amplitude and its corresponding frequency are identified.

[0060] Zero-padding the acceleration data is a prerequisite for performing a Fourier transform. Performing a Fourier transform can filter out noise in the acceleration data, ensuring that the acceleration amplitude and frequency data are relatively pure, and thus analyze the accurate and reliable maximum displacement amplitude.

[0061] The displacement amplitude corresponding to the largest amplitude in the acceleration amplitude-frequency data is not necessarily the maximum displacement amplitude, but the maximum displacement amplitude is most likely to appear near the largest amplitude. Therefore, in this embodiment, the largest amplitude is taken as the starting point of the acceleration amplitude-frequency data. The maximum displacement amplitude corresponding to adjacent amplitudes is gradually collected on both sides of the starting point. This can be achieved by setting a data interval, with the pointer starting from the starting point and continuously moving to both sides at this interval. The displacement amplitude at the pointer position is calculated for each movement. After multiple movements, or even after traversing the entire acceleration amplitude-frequency data, all displacement amplitudes are summarized to find the maximum displacement amplitude. This method can significantly reduce the workload of finding the maximum displacement amplitude. Furthermore, based on the acceleration data time, it can be implemented by placing acceleration sensors on the road roller, reducing the deployment cost of this method.

[0062] As one embodiment, experimental verification shows that when the road roller used is a single-drum vibratory roller, the value range of the first threshold is 17-22Hz, and the value range of the second threshold is 23-25Hz.

[0063] As one embodiment, the actual vibration frequency can also be obtained from the vibration acceleration of the road roller based on the acceleration sensor, and then obtained from the vibration acceleration of the road roller.

[0064] As mentioned earlier, the vibration compaction capacity of the road roller is compared with the actual vibration frequency value to determine whether it meets the vibration compaction requirements of the soil layer of that thickness. As one embodiment, the preset excitation frequency of the road roller is multiplied by a fixed coefficient as the second threshold. The fixed coefficient can be 0.9, allowing for a 10% detection error.

[0065] As one embodiment, obtaining the compaction degree value of the soil layer includes: acquiring the vibration acceleration of the road roller; performing a Fourier transform on the acceleration data after zero-padding to obtain acceleration amplitude-frequency data; extracting the 0.5 harmonic frequency domain amplitude and the fundamental frequency domain amplitude from the acceleration amplitude-frequency data; and calculating the compaction degree value of the soil layer using the following formula:

[0066] In the formula, ST3 is the compaction degree value of the soil layer, and A 0.5 A is the frequency domain amplitude at 0.5 times the frequency. 基 R is the fundamental frequency domain amplitude. c The amplification factor is A, which is the frequency domain amplitude at 0.5 octaves. 0.5 With fundamental frequency domain amplitude A 基 The difference between them is small, so an amplification factor R needs to be introduced. c This amplifies the numerical value of the ratio, making the soil compaction value ST3 more intuitive.

[0067] To illustrate the solution of this embodiment, let's take a more specific example. A 22-ton fully hydraulic single-drum vibratory roller is to perform the sixth vibration compaction operation on a water-stabilized layer. The acceleration sensor 2, which is arranged on the vibratory drum of the roller, obtains continuous acceleration data of the vibratory drum in the vertical direction from 0 to 3.512s (denoted as T1) from the start of the vibration start button. If the sampling frequency is 1000Hz, then 3512 acceleration data points are collected.

[0068] T1 is the vibration start-up stage, which refers to the period when the road roller goes from not vibrating to vibrating, and the vibration frequency rises from 0Hz to the expected frequency value. This stage usually lasts no more than 10 seconds. The vibration start-up time refers to the time from when the vibration start button is pressed. The preferred value of the vibration start-up time T1 is 2.5 to 4.5 seconds.

[0069] According to the principles of physics, the natural frequency of a material is positively correlated with its stiffness, and the degree of compaction of a material is also positively correlated with its stiffness. Therefore, it can be determined that the natural frequency of a material is correlated with the degree of compaction of the material. The degree of compaction of a material can be determined by its natural frequency. Generally speaking, for soil materials with a fixed composition, the higher the natural frequency, the denser the soil. On the other hand, the natural frequency is an inherent characteristic of the material and is difficult to obtain in real time, making it difficult to obtain the resonance frequency between the road roller and the soil layer in real time.

[0070] However, for a specific road roller, the second-order natural frequency value of the "road roller-soil layer" vibration system when the road roller and the soil layer work together is related to the natural frequency of the soil material and can be obtained in real time. Therefore, the second-order natural frequency value between the road roller and the soil layer is used instead of the resonant frequency between the road roller and the soil layer for discrimination, so as to advance the identification of the degree of soil compaction to the vibration start stage.

[0071] The time from the start of vibration to reaching the resonant frequency of a vibratory roller is typically about 3 seconds. Based on past experience, the start time T1 for the sixth compaction of the water-stabilized layer is determined to be 3.512 seconds to ensure that the acceleration data within this start time indeed includes acceleration data at the resonant frequency. If the sampling frequency is 1000Hz, 3512 acceleration data points need to be analyzed. Starting from the start time 0, 512 acceleration data points are sequentially extracted, padded to 2048, and then subjected to a Fourier transform to filter out frequency components outside a specified frequency band, such as 6-30Hz, resulting in a set of acceleration amplitude-frequency data. This set of acceleration amplitude-frequency data is then filtered to obtain the maximum acceleration amplitude and its corresponding frequency. The displacement amplitude at the corresponding frequency is calculated using a formula, and this displacement amplitude and its corresponding frequency are recorded in the first data series. This process is repeated for 40 acceleration data points until all 3512 data points have been processed, at which point all displacement amplitudes and their corresponding frequencies are recorded in the first data series. The maximum displacement amplitude is selected from the first data series, and its corresponding frequency is used as the second-order natural frequency of the system between the roller and the soil layer, replacing the resonant frequency for discrimination. The first threshold is set to 21Hz.

[0072] Assumption 1: The natural frequency of the second-order system between the roller and the soil layer is 22.5Hz, which is greater than the first threshold. This indicates that the soil layer is already sufficiently compacted, and continued compaction may damage the pavement. Continuing to compact would be ineffective. Therefore, compaction control is implemented: vibration is stopped. This step completes the identification and control of the first time period, advancing compaction control to the vibration initiation stage, thereby avoiding potentially destructive compaction in the future.

[0073] Assumption 2: The natural frequency of the second-order system between the roller and the soil layer is 17Hz, which is less than the first threshold. It is determined that continued compaction will further densify the pavement, and continued compaction is effective compaction. Therefore, compaction control is implemented: continue vibration.

[0074] Typically, after pressing the vibration button, depending on the material and the degree of compaction, if the compaction equipment can meet the compaction requirements of the material being compacted, the actual vibration frequency can rise from 0 to the expected frequency within about 5 seconds, such as 28Hz for a single-drum vibratory roller or 50Hz for a double-drum vibratory roller. If the compaction equipment cannot meet the compaction requirements of the material being compacted, the time for the actual vibration frequency to rise from 0Hz to the expected frequency (such as 28Hz for a single-drum vibratory roller or 50Hz for a double-drum vibratory roller) will be significantly longer. In some cases, the actual vibration frequency may not even reach the expected frequency after 20 seconds, leading to the destruction of the compacted pavement.

[0075] Based on assumption 2, after the above discrimination, the actual vibration frequency value of the road roller is obtained within the second time period T2 (T2 is preferably 5-10s). The preset excitation frequency of the road roller is 28Hz, the fixed coefficient is 0.9, and the second threshold is set to 25.2Hz.

[0076] Assumption 3: Performing a fast Fourier transform on the actual vibration frequency value within T2, the actual vibration frequency value at the end of T2 is 22.3Hz, which is less than the second threshold. This indicates that the vibrating wheel of the road roller cannot complete the vibration for a long time, that is, the compaction equipment capacity does not meet the compaction requirements of the material being compacted. It is judged that the quality of continued compaction is uncontrollable, that is, continued compaction is ineffective. Therefore, compaction control is implemented: vibration is stopped.

[0077] Assumption 4: Performing a fast Fourier transform on the actual vibration frequency value within T2, the actual vibration frequency value at the end of T2 is 28.3Hz, indicating that the vibratory roller can complete the vibration within the expected time, that is, the compaction equipment can meet the compaction requirements of the material being compacted. It is determined that continued compaction is effective, so compaction control is implemented: continue vibration.

[0078] In one embodiment, a frequency sensor is used to measure the motor speed, which is then converted into the actual vibration frequency corresponding to time point T2. Directly measuring the motor speed using a frequency sensor to obtain the actual vibration frequency is more intuitive and accurate.

[0079] Typically, after vibration is initiated and the vibration frequency approaches the preset excitation frequency, the excitation frequency of the roller tends to stabilize, reaching a condition essentially the same as the excitation frequency specified in EU Technical Specification 17006:2016 "Earthworks - Continuous Compaction Control (CCC)" which states that "during the measurement period, the excitation frequency should be maintained within the range of Δf < 2Hz". At this point, the degree of soil compaction can be determined by comparing the changes in its effective compaction work, harmonic components, and dynamic stiffness. The compaction degree value after T2 can be obtained by multiplying the ratio of the frequency domain amplitude in the vertical direction to the fundamental frequency domain amplitude by a magnification factor (e.g., 1500). The resulting compaction degree value represents the degree of double-jump of the vibratory drum, which can be used to determine whether the soil is over-compacted, thereby indirectly identifying whether the roller has driven over a fully compacted soil layer.

[0080] Based on hypothesis 4, after T2, the acceleration data of 512 points at a sampling frequency of 1000Hz are analyzed in a third time period T3 (duration 0.5s, preferably 0.5 to 1s). The compaction degree of the soil layer in each T3 period is obtained based on the acceleration data and compared with the third threshold, which is set to 450 and the amplification factor is 1500.

[0081] Assumption 5: If the compaction degree value is 500 within a certain T3 cycle, which is greater than the third threshold, it indicates that the vibratory roller has experienced severe double-jumping, possibly having already completed the vibratory compaction of the uncompacted portion and entered the already compacted area. Continuing compaction would damage the ply, so further compaction is deemed ineffective. Therefore, compaction control is implemented: vibration is stopped. Through the detection and judgment in this step, the effectiveness of subsequent compaction can be determined and controlled when the excitation frequency is basically stable.

[0082] Example 3:

[0083] This embodiment provides a control device for a road roller. Referring to Figure 2, it includes a controller 1, which is used to acquire the second-order natural frequency value of the system between the road roller and the soil layer, and to stop the vibration compaction operation in response to the second-order natural frequency value reaching a first threshold.

[0084] The actual vibration frequency value of the road roller is obtained, and the vibration compaction operation is stopped when the actual vibration frequency value is less than the second threshold.

[0085] Obtain the compaction degree value of the soil layer, and stop the vibration compaction operation in response to the compaction degree value being greater than the third threshold;

[0086] Accelerometer 2 is electrically connected to controller 1 and is used to acquire the vibration acceleration of the road roller. Controller 1 acquires the second-order natural frequency value of the system between the road roller and the soil layer, the actual vibration frequency value of the road roller, and the compaction degree value of the soil layer based on the vibration acceleration.

[0087] This includes obtaining the second-order natural frequency values ​​of the system between the roller and the soil layer, including:

[0088] The vibration acceleration of the road roller is obtained, and the acceleration data is collected within a set time period starting from zero vibration acceleration;

[0089] After zero-padding the acceleration data, a Fourier transform is performed to obtain the acceleration amplitude-frequency data;

[0090] Find the frequency corresponding to the maximum amplitude from the acceleration amplitude-frequency data, and calculate the displacement amplitude at the frequency corresponding to the maximum amplitude.

[0091] Starting from the frequency corresponding to the maximum amplitude, the data is shifted, and the displacement amplitude of the frequencies at adjacent positions is calculated;

[0092] Find the maximum displacement amplitude from multiple displacement amplitudes, and use the frequency corresponding to the maximum displacement amplitude as the second-order natural frequency value of the system between the roller and the soil layer.

[0093] The road roller is a single-drum vibratory road roller. The first threshold value ranges from 17 to 22 Hz, and the second threshold value ranges from 23 to 25 Hz.

[0094] Obtain the vibration acceleration of the road roller, and then obtain the actual vibration frequency based on the vibration acceleration.

[0095] The second threshold is obtained by multiplying the preset excitation frequency of the road roller by a fixed coefficient.

[0096] Obtaining the compaction degree value of the soil layer includes,

[0097] The vibration acceleration of the road roller is obtained, and the acceleration data is zero-padded and then subjected to Fourier transform to obtain the acceleration amplitude-frequency data.

[0098] Extract the 0.5 harmonic frequency domain amplitude and the fundamental frequency domain amplitude from the acceleration amplitude-frequency data;

[0099] The degree of soil compaction is calculated using the following formula:

[0100] In the formula, ST3 is the compaction degree value of the soil layer, and A 0.5 A is the frequency domain amplitude at 0.5 times the frequency. 基 R is the fundamental frequency domain amplitude. c This is the magnification factor.

[0101] The control method of the road roller provided in Embodiment 1 or 2 can be applied to the control device of the road roller provided in this embodiment, and has the corresponding functional modules and beneficial effects of the execution method. The control device of the road roller provided in this embodiment has the same technical effects as Embodiment 1 or 2, and will not be described again here.

[0102] Example 4:

[0103] This embodiment provides a computer device, including a processor and a memory connected to the processor. The memory stores a computer program, and when the computer program is executed by the processor, it performs the steps of the control method for a road roller as provided in Embodiment 1 or 2.

[0104] The computer device can be a server or an electronic terminal. Referring to Figure 3, as one embodiment, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores data acquired and generated in the control method of the road roller. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network connection. When the computer program is executed by the processor, it implements the control method of the road roller provided in Embodiment 1 or 2.

[0105] Those skilled in the art will understand that the structure shown in Figure 3 is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0106] The computer device provided in this embodiment has the same technical effects as that in Embodiment 1 or 2, and will not be described again here.

[0107] Example 5:

[0108] This embodiment provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the control method for a road roller provided in Embodiment 1 or Embodiment 2.

[0109] The computer-readable storage medium provided in this embodiment has the same technical effects as that in Embodiment 1 or 2, and will not be described again here.

[0110] Example 6:

[0111] This embodiment provides a computer program product storing a computer program that, when executed by a processor, implements the steps of the control method for a road roller provided in Embodiment 1 or Embodiment 2. The computer program product provided in this embodiment can be transmitted, distributed, and downloaded via the Internet in the form of signals.

[0112] The computer program product provided in this embodiment has the same technical effects as that in Embodiment 1 or 2, and will not be described again here.

[0113] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0114] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more flowchart illustrations and / or one or more block diagrams.

[0115] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0116] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0117] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0118] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0119] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A control method for a road roller, characterized in that it includes, The second-order natural frequency value of the system between the roller and the soil layer is obtained, and the vibration compaction operation is stopped when the second-order natural frequency value reaches the first threshold. The actual vibration frequency value of the road roller is obtained, and the vibration compaction operation is stopped in response to the actual vibration frequency value being less than a second threshold. Obtain the compaction degree value of the soil layer, and stop the vibration compaction operation in response to the compaction degree value being greater than a third threshold.

2. The control method for the road roller according to claim 1, characterized in that, The second-order natural frequency value of the system between the road roller and the soil layer is obtained. include, The vibration acceleration of the road roller is obtained, and acceleration data is acquired within a set time period starting from when the vibration acceleration is zero; After zero-padding the acceleration data, a Fourier transform is performed to obtain the acceleration amplitude-frequency data; Find the frequency corresponding to the maximum amplitude from the acceleration amplitude-frequency data, and calculate the displacement amplitude at the frequency corresponding to the maximum amplitude. Starting from the frequency corresponding to the maximum amplitude, the data is shifted, and the displacement amplitude of the frequencies at adjacent positions is calculated; Find the maximum displacement amplitude from multiple displacement amplitudes, and use the frequency corresponding to the maximum displacement amplitude as the second-order natural frequency value of the system between the road roller and the soil layer.

3. The control method for the road roller according to claim 1, characterized in that, The road roller is a single-drum vibratory road roller, the first threshold value ranges from 17 to 22 Hz, and the second threshold value ranges from 23 to 25 Hz.

4. The control method for the road roller according to claim 1, characterized in that, The vibration acceleration of the road roller is obtained, and the actual vibration frequency is obtained based on the vibration acceleration.

5. The control method for the road roller according to claim 1, characterized in that, The second threshold is calculated by multiplying the preset excitation frequency of the road roller by a fixed coefficient.

6. The control method for the road roller according to claim 1, characterized in that, The process of obtaining the compaction degree value of the soil layer includes, The vibration acceleration of the road roller is obtained, and the acceleration data is zero-padded and then subjected to Fourier transform to obtain the acceleration amplitude-frequency data. The 0.5 harmonic frequency domain amplitude and the fundamental frequency domain amplitude are extracted from the acceleration amplitude-frequency data; The compaction degree value is calculated using the following formula: In the formula, ST3 is the compaction degree value of the soil layer, and A 0.5 A is the frequency domain amplitude at 0.5 times the frequency. 基 R is the fundamental frequency domain amplitude. c This is the magnification factor.

7. A control device for a road roller, characterized in that, include, The controller (1) is used to acquire the second-order natural frequency value of the system between the roller and the soil layer, and to stop the vibration compaction operation in response to the second-order natural frequency value reaching a first threshold. The actual vibration frequency value of the road roller is obtained, and the vibration compaction operation is stopped in response to the actual vibration frequency value being less than a second threshold. Obtain the compaction degree value of the soil layer, and stop the vibration compaction operation in response to the compaction degree value being greater than a third threshold; An acceleration sensor (2) is electrically connected to the controller (1) to obtain the vibration acceleration of the road roller; the controller (1) obtains the second-order natural frequency value of the road roller and the soil layer, the actual vibration frequency value of the road roller and the compaction degree value of the soil layer based on the vibration acceleration.

8. A computer device, characterized in that, It includes a processor and a memory connected to the processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, it performs the steps of the control method for the road roller as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the control method for the road roller according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the control method for the road roller according to any one of claims 1 to 6.

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