Method for slip control of a milling machine

Abstract

The present application relates to the technical field of engineering machinery, and especially relates to a milling and ploughing machine slip control method, which comprises the following steps: S1, setting a slip preset pressure and an optimal working pressure of a working pump, and starting working of the milling and ploughing machine; S2, detecting whether the milling and ploughing machine slips, if not, the working pump works according to the optimal working pressure, and if yes, the next step is performed; S3, entering slip control; S4, judging whether the output pressure of the working pump is not greater than the slip preset pressure, if yes, the next step is performed; S5, controlling the displacement of a hydraulic motor corresponding to a wheel existing slip to decrease, and simultaneously reducing the displacement of the working pump, so that the speed of the milling and ploughing machine is kept constant until the slip is eliminated, and returning to step S2. The present application can judge the type of slip, ensure the driving speed of the vehicle stable in the process of anti-slip program control, and ensure the working efficiency.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, and in particular to a method for controlling slippage in a milling machine. Background Technology

[0002] Milling machinery, such as milling machines and cold recycling machines, commonly employs a four-wheel independent drive system. However, the adhesion conditions on the road surface during milling operations are highly uncertain: the roughness of the road surface itself, residual rain and snow, and unrecovered asphalt concrete particles after milling all contribute to differences in the adhesion coefficients between the drive wheels. Furthermore, the transfer of adhesion weight when driving on slopes leads to significant differences and variability in the actual adhesion force between the drive wheels. During milling operations, wheels with poor adhesion frequently slip. Current technology uses a flow divider valve to control slippage in milling machines. When slippage occurs, the flow divider valve activates, distributing the output flow from the working pump evenly to the four drive motors to achieve deslippage. However, this approach is reactive; the operator manually opens the flow divider valve after noticing slippage, and repeated operation is required when slippage occurs, which is a drawback.

[0003] To address the aforementioned issues, the current mainstream technical approach is to remove the flow divider valve and replace the travel motor with an electro-proportional control motor. When the program detects slippage, it automatically deslips by adjusting the motor displacement corresponding to the slipping wheel, eliminating the need for repeated operator intervention. Currently, slippage control in milling machines faces the following problems in practical applications:

[0004] (1) Slippage can be divided into slippage caused by heavy load and slippage caused by poor adhesion, which cannot be judged; (2) During the anti-slip program control process, the vehicle speed is unstable due to frequent changes in motor displacement, resulting in slow slippage speed; (3) The operating speed is controlled by the operator's experience, and the operating efficiency is difficult to guarantee.

[0005] Therefore, a method for controlling slippage in milling machines is needed to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a milling machine slip control method that can determine the type of slip, ensure stable vehicle speed during anti-slip program control, and guarantee work efficiency.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] The method for controlling slippage in a milling machine includes the following steps:

[0009] S1. Set the slippage preset pressure and optimal working pressure of the working pump, and the milling machine will start working.

[0010] S2. Check if the milling machine is slipping. If not, the working pump operates at the optimal working pressure. If yes, proceed to the next step.

[0011] S3, Enter slip control;

[0012] S4. Determine whether the output pressure of the working pump is not greater than the slippage preset pressure. If so, proceed to the next step.

[0013] S5. Control the hydraulic motor corresponding to the slipping wheel to reduce its displacement, and simultaneously reduce the displacement of the working pump to keep the milling machine's speed constant until it is freed from the obstacle, then return to step S2.

[0014] Further, in step S2, the working pump operating at the optimal operating pressure includes the following steps:

[0015] S21. Check whether the output pressure of the working pump is less than the optimal operating pressure. If so, proceed to the next step.

[0016] S22. Prompt to increase the traveling speed of the milling machine until the output pressure of the working pump reaches the optimal operating pressure.

[0017] Furthermore, step S2 also includes step S23, prompting the user to enter the optimal working state.

[0018] Furthermore, light or voice alarms can be used for prompting.

[0019] Furthermore, in step S4, if the output pressure of the working pump is greater than the slippage preset pressure, the vehicle speed is reduced to deslip, and after deslippage, the process proceeds to step S2.

[0020] Furthermore, if the output pressure of the working pump is greater than the slippage preset pressure, then the output pressure of the working pump at this time is taken as the new slippage preset pressure.

[0021] Furthermore, a warning will be given when the vehicle speed is reduced to allow for skidding.

[0022] Furthermore, a pressure sensor is installed on the working pump, which is used to collect the pressure at the high-pressure output port of the working pump.

[0023] Furthermore, each wheel's corresponding motor is equipped with a speed sensor for speed detection. When the difference between the speed measured by one of the speed sensors and the speed measured by the other speed sensors is greater than a preset difference, slippage is identified.

[0024] Furthermore, the preset difference can be calibrated.

[0025] The beneficial effects of this invention are:

[0026] The present invention provides a method for controlling slippage in a milling machine. First, a preset slippage pressure and an optimal operating pressure are set for the working pump. Then, the milling machine is started to begin cutting and working. The system detects whether slippage occurs during a sudden impact. If not, the working pump operates at the optimal operating pressure. If slippage occurs, the system enters a deslippage control phase. It determines whether the output pressure of the working pump is not greater than the preset slippage pressure. If so, the displacement of the hydraulic motor corresponding to the slipping wheel is reduced, simultaneously decreasing the displacement of the working pump to maintain a constant speed for the milling machine until it is freed from the obstacle. Through this method, if the milling machine does not slip, it operates at the set optimal operating pressure, ensuring work efficiency. If slippage occurs, the type of slippage is determined by comparing the output pressure of the working pump with the preset slippage pressure, and control is implemented accordingly to ensure effective deslippage control. When the output pressure of the working pump is not greater than the slippage preset pressure, the slippage is caused by poor adhesion. By controlling the reduction of the displacement of the hydraulic motor corresponding to the slipping wheel, the output torque is increased by reducing the speed of the slipping wheel, and the displacement of the working pump is reduced at the same time. This allows the milling machine to maintain a constant speed while quickly getting out of trouble. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0028] Figure 1 This is a flowchart of a milling machine slip control method according to the present invention. Detailed Implementation

[0029] Before explaining any implementation of this application in detail, it should be understood that this application is not limited to its application to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0030] In this application, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0031] In this application, the terms "connection," "combination," "coupling," and "installation" can refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the need for an intermediary, while an indirect connection refers to two parts or components each being connected to at least one intermediary, with the connection achieved through the intermediary. Furthermore, "connection" and "coupling" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.

[0032] In this application, those skilled in the art will understand that relative terms (e.g., “about,” “approximately,” “basically,” etc.) used in conjunction with quantities or conditions are to include the values ​​and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances associated with the particular value due to manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​not using relative terms should also be disclosed as specific values ​​with tolerances. Furthermore, “basically” when expressing relative angular relationships (e.g., substantially parallel, substantially perpendicular) may refer to a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) added to or subtracted from the indicated angle.

[0033] In this application, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0034] In this application, the directional terms "upper," "lower," "left," "right," "front," and "rear" are used to describe the orientation and positional relationships shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when an element is mentioned as being connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as upper side, lower side, left side, right side, front side, and rear side not only represent positive orientation but can also be understood as lateral orientation. For example, "below" can include directly below, lower left, lower right, lower front, and lower rear.

[0035] During milling machine operation, the vehicle sometimes slips, and the milling machine's efficiency is low due to the driver's limited experience. To solve these problems and ensure stable vehicle speed during anti-slip control, thus guaranteeing work efficiency, such as... Figure 1 As shown, this invention provides a method for controlling slippage in a milling machine. The method for controlling slippage in a milling machine includes the following steps:

[0036] S1. Set the slippage preset pressure and optimal working pressure of the working pump, and the milling machine will start working.

[0037] S2. Check if the milling machine is slipping. If not, the working pump operates at the optimal working pressure. If so, proceed to the next step.

[0038] S3, Enter slip control;

[0039] S4. Determine if the output pressure of the working pump is not greater than the slippage preset pressure. If so, proceed to the next step.

[0040] S5. Control the hydraulic motor corresponding to the slipping wheel to reduce its displacement, and simultaneously reduce the displacement of the working pump to keep the milling machine's speed constant until it is freed from the obstacle, then return to step S2.

[0041] Using the above method, if the milling machine does not slip, it operates at the set optimal working pressure to ensure work efficiency. If slippage occurs, the type of slippage is determined by comparing the output pressure of the working pump with the preset slippage pressure, and control is implemented accordingly to ensure effective deslippage control. When the output pressure of the working pump is not greater than the preset slippage pressure, the slippage is caused by poor adhesion. By controlling the reduction of the displacement of the hydraulic motor corresponding to the slipping wheel, the output torque is increased by reducing the speed of the slipping wheel, and the displacement of the working pump is reduced simultaneously. This allows the milling machine to maintain a constant speed while quickly extricating itself from the obstacle.

[0042] Furthermore, in step S2, the working pump operates at the optimal operating pressure, including the following steps:

[0043] S21. Check if the output pressure of the working pump is less than the optimal operating pressure. If so, proceed to the next step.

[0044] S22. The operator is prompted to increase the milling machine's travel speed until the working pump's output pressure reaches the optimal operating pressure. Specifically, a pressure sensor is installed on the working pump to collect the pressure at the pump's high-pressure output port. The pressure sensor communicates with the vehicle controller, transmitting the collected pressure data. The vehicle controller, in turn, communicates with the working pump. By comparing the pressure collected by the sensor with the optimal operating pressure, the vehicle controller prompts the operator to increase the milling machine's travel speed when the working pump's output pressure is lower than the optimal operating pressure. This increases the working pump's output pressure until the optimal operating pressure is reached. Setting the optimal operating pressure ensures the milling machine operates at its best, guaranteeing work efficiency. Furthermore, the system makes adaptive adjustments based on prompts until the working pump reaches the optimal operating pressure. The optimal operating pressure of the working pump can be obtained through bench testing or determined by collecting data from actual work operations; no further limitations are imposed here.

[0045] Furthermore, step S2 also includes step S23, prompting the operator to enter the optimal working state. When the working pump is in the optimal working state, the operator is prompted, thus enabling the operator to understand the working status of the milling machine in a timely manner.

[0046] Furthermore, visual or audio alarms are used for alerts. Specifically, an alarm device is installed on the milling machine, electrically connected to the vehicle controller, to promptly and effectively remind the driver via visual or audio alarms. The lighting display can be integrated into the instrument panel. In some embodiments, when the optimal operating condition is not reached, the indicator light on the instrument panel flashes as a reminder. Once the optimal operating condition is reached, the indicator light on the instrument panel stops flashing.

[0047] Further, in step S4, if the output pressure of the working pump is greater than the slippage preset pressure, the vehicle speed is reduced to allow slippage to occur until slippage is achieved, at which point the process proceeds to step S2. When the output pressure of the working pump is greater than the slippage preset pressure, it is determined that slippage is caused by excessive load. At this time, the vehicle speed is reduced to increase the output torque, thereby ensuring that the vehicle can overcome the load resistance and continue working. To ensure working efficiency after slippage, after deceleration and slippage, the process proceeds to step S2, where the working pump operates at the optimal operating pressure.

[0048] Furthermore, if the output pressure of the working pump exceeds the slippage preset pressure, then the current output pressure of the working pump is used as the new slippage preset pressure. Specifically, the milling machine's center of gravity is close to the front wheels. Therefore, slippage of the front wheels is usually caused by excessive load. By self-learning the working pump's output pressure as the new slippage preset pressure, it can effectively adapt to the current working environment, thus facilitating the determination of whether to trigger the deceleration and slippage mechanism. When the slippage preset pressure is not triggered, a constant working speed can be maintained, thereby ensuring work efficiency.

[0049] Furthermore, a warning should be given when reducing speed to prevent skidding. Specifically, this can be done using lights or voice prompts, which will not be elaborated on here. By reminding the driver to reduce speed, the driver can better understand the vehicle's operating status. If reducing speed fails to overcome skidding, the driver can intervene promptly to analyze the road conditions.

[0050] Furthermore, each wheel's corresponding motor is equipped with a speed sensor for detecting rotational speed. When the difference between the rotational speed measured by one speed sensor and the speed measured by the others exceeds a preset difference, slippage is identified. During slippage, the slipping wheel will spin in place, and because the friction on the slipping wheel is lower, its rotational speed is higher, exceeding that of the other wheels. This method allows for accurate identification of which wheel is slipping, facilitating control and enabling the vehicle to quickly extricate itself from trouble.

[0051] Furthermore, the preset difference can be calibrated. Since the slippage effect varies in each environment, different preset differences can be set according to different environments, thereby making it easier to quickly identify the slipping wheel for different working environments.

[0052] This milling machine slip control method has the following advantages.

[0053] (1) Implement the function of self-judgment of slippage cause, and autonomously judge whether the slippage is due to high load or poor adhesion. The milling machine can learn and adapt to different working conditions.

[0054] (2) By adjusting the flow rate of the working pump and the displacement of the motor corresponding to the slipping wheel, the machine speed is kept constant during the control process, thus ensuring the working efficiency of the milling machine.

[0055] (3) Maximize the efficiency of milling machine operation.

[0056] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for controlling slippage in a milling machine, characterized in that, Includes the following steps: S1. Set the slippage preset pressure and optimal working pressure of the working pump, and the milling machine will start working. S2. Check if the milling machine is slipping. If not, the working pump operates at the optimal working pressure. If yes, proceed to the next step. S3, Enter slip control; S4. Determine whether the output pressure of the working pump is not greater than the slippage preset pressure. If so, proceed to the next step. S5. Control the hydraulic motor corresponding to the slipping wheel to reduce its displacement, and simultaneously reduce the displacement of the working pump to keep the milling machine's speed constant until it is freed from the entanglement, then return to step S2. In step S4, if the output pressure of the working pump is greater than the slippage preset pressure, the vehicle speed is reduced to deslip. After deslippage, the process proceeds to step S2.

2. The milling machine slippage control method according to claim 1, characterized in that, In step S2, the operation of the working pump at the optimal operating pressure includes the following steps: S21. Check whether the output pressure of the working pump is less than the optimal operating pressure. If so, proceed to the next step. S22. Prompt to increase the traveling speed of the milling machine until the output pressure of the working pump reaches the optimal operating pressure.

3. The milling machine slippage control method according to claim 2, characterized in that, Step S2 also includes step S23, prompting that the system has entered the optimal working state.

4. The milling machine slippage control method according to claim 2, characterized in that, Use lights or voice alarms to provide alerts.

5. The milling machine slippage control method according to claim 1, characterized in that, If the output pressure of the working pump is greater than the slippage preset pressure, then the output pressure of the working pump at this time shall be used as the new slippage preset pressure.

6. The milling machine slippage control method according to claim 1, characterized in that, Provide a warning when reducing vehicle speed to allow for skidding.

7. The milling machine slippage control method according to claim 1, characterized in that, A pressure sensor is installed on the working pump to collect the pressure at the high-pressure output port of the working pump.

8. The milling machine slippage control method according to claim 1, characterized in that, Each wheel's corresponding motor is equipped with a speed sensor for detecting the rotational speed. When the difference between the rotational speed collected by one of the speed sensors and the rotational speed collected by the other speed sensors is greater than a preset difference, slippage is identified.

9. The milling machine slippage control method according to claim 8, characterized in that, The preset difference can be calibrated.

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