Hydraulic-walking cooperative anti-skid control method for crawler-type engineering machinery

Abstract

The invention relates to the technical field of engineering machinery control, in particular to a crawler-type engineering machinery hydraulic-walking cooperative anti-skid control method, which comprises the following steps: through a hydraulic pressure difference-crawler rotating speed difference two-parameter fusion monitoring mechanism, combining pre-stored threshold value mapping relations of different low-adhesion road surfaces (muddy, gravel and ramp); according to single-side or double-side slipping, a cooperative control strategy of slipping side flow reduction and non-slipping side flow increase or double-side flow reduction and system pressure increase is adopted, meanwhile, the total output flow of the system is kept stable by adjusting the displacement of a hydraulic pump, it is guaranteed that the overall walking speed deviation of equipment is smaller than or equal to 0.2 km / h, and the stability of the system is guaranteed. According to the method, misjudgment and control are effectively avoided, the anti-skid response speed and the recognition accuracy are improved, the working efficiency is considered while the walking stability is guaranteed, and the service life of related elements is prolonged.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery control technology, specifically a hydraulic-walking coordinated anti-slip control method for tracked engineering machinery. Background Technology

[0002] Tracked construction machinery is widely used in complex and harsh working conditions such as mining, construction, and agriculture and forestry due to its low ground pressure and strong off-road capability. Its walking drive mostly uses a closed or open hydraulic system, with hydraulic motors driving the tracks for movement. However, when operating on low-friction surfaces such as mud, slippery surfaces, loose gravel, or slopes, slippage on one or both tracks is very likely to occur.

[0003] Existing anti-slip control solutions for track slippage have the following main shortcomings: 1. Limited Detection Dimensions: Most solutions rely solely on speed sensors to monitor the speed difference between the left and right tracks to determine slippage. This method cannot distinguish between normal speed differences caused by uneven loads on both sides of the road surface (such as off-center loading) and true slippage caused by insufficient adhesion, which can easily lead to misjudgments and misoperations, or cause a delayed response in the early stages of slippage because the speed difference has not reached a fixed threshold.

[0004] 2. Poor coordination of control strategies: Common anti-slip measures often involve simply slowing down or mechanically braking the slipping track. This approach is not coordinated with the overall flow and pressure control of the hydraulic system, often resulting in a sudden drop in the overall machine travel speed, severely impacting operational efficiency and continuity. Furthermore, abrupt mechanical braking accelerates track wear and generates hydraulic shocks, damaging the lifespan of hydraulic components.

[0005] 3. Poor adaptability to road conditions: Different low-adhesion road surfaces (such as muddy and gravel surfaces) have significantly different physical characteristics, and their critical conditions for inducing slippage also differ. Existing technologies mostly use fixed anti-skid thresholds, which are difficult to adapt to varying road conditions. This results in untimely anti-skid action on soft surfaces and frequent false triggering on bumpy surfaces, leading to unstable control performance.

[0006] Therefore, there is an urgent need to propose an anti-skid control method that can integrate multi-parameter information, achieve coordinated response of hydraulic and walking systems, and adapt to different road conditions, so as to improve the walking stability, operation efficiency and reliability of tracked engineering machinery in complex environments. Summary of the Invention

[0007] The purpose of this invention is to provide a hydraulic-walking coordinated anti-slip control method for tracked engineering machinery to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A hydraulic-walking coordinated anti-slip control method for tracked construction machinery, applied to tracked construction machinery including left / right track hydraulic motors, hydraulic pumps, controllers, and sensor groups, includes the following steps: Step 1: Parameter Acquisition and Calculation: The controller acquires real-time data from pressure sensors installed at the inlet and outlet of the hydraulic motors of the left and right tracks, and calculates the pressure differences ΔP1 and ΔP2 between the inlet and outlet of the hydraulic motors of the left and right tracks, as well as their average value ΔP. avg Simultaneously, data from the speed sensors installed on the left and right track drive wheels are collected to obtain the left and right track speeds n1 and n2, and the track speed difference Δn=|n1-n2| and the speed difference ratio k=Δn / max(n1,n2) are calculated. Step 2, Road surface identification and threshold matching: The controller has a pre-stored mapping relationship of "pressure difference threshold range - speed difference ratio threshold" for several typical low-adhesion road surfaces. Based on the real-time calculated ΔPavg, the current road surface type and the corresponding speed difference ratio threshold k0 are matched. Step 3, Slippage Determination: When the percentage of the rotational speed difference k is greater than the threshold k0 of the current road surface type, and the pressure difference ΔP1 of the left track hydraulic motor or the pressure difference ΔP2 of the right track hydraulic motor is less than the average value ΔP avg When the value is 0.7 times the value, it is determined that the corresponding track has slipped; Step 4, Cooperative Anti-slip Control: If it is determined that the slippage is on one side of the track, the flow rate of the hydraulic motor on the slipping side is reduced, the flow rate of the hydraulic motor on the non-slipping side is increased, and the hydraulic pump is adjusted to maintain a stable total output flow rate of the system; if it is determined that the slippage is on both sides of the track, the flow rate of the hydraulic motors on both sides is reduced simultaneously, the working pressure of the hydraulic system is increased, and an alarm is triggered at the same time. Step 5, Exit and Resume: When the percentage of the rotational speed difference k is less than or equal to 0.8 × k0 within a continuously preset time period, and both ΔP1 and ΔP2 are greater than or equal to 0.8 × ΔP avg When the road surface adhesion is restored, the controller controls each actuator to return to its initial state before anti-skid control.

[0009] As a further aspect of the present invention: the typical low-adhesion road surface includes at least muddy road surface, gravel road surface and sloping road surface; wherein, the pressure difference threshold range corresponding to the muddy road surface is 3-8 MPa, and the speed difference ratio threshold k0 is 8%; the pressure difference threshold range corresponding to the gravel road surface is 8-15 MPa, and the speed difference ratio threshold k0 is 12%; the pressure difference threshold range corresponding to the sloping road surface is 15-25 MPa, and the speed difference ratio threshold k0 is 10%.

[0010] As a further aspect of the present invention: the sampling frequency of the sensor group is 10-20Hz, and the command response time of the controller is ≤50ms.

[0011] As a further aspect of the present invention: when one side of the track slips, the flow rate of the hydraulic motor on the slipping side is reduced by 15-25%, while the flow rate of the hydraulic motor on the non-slipping side is increased by 10-15%.

[0012] As a further aspect of the present invention: when both tracks slip, the flow rate of both hydraulic motors is reduced by 10-20% simultaneously, and the opening pressure of the hydraulic system relief valve is increased by 5-8%.

[0013] As a further aspect of the present invention: the controller also supports receiving road surface type instructions manually input by the operator, and the priority of the manual instructions is higher than the automatic recognition results in step two.

[0014] As a further aspect of the present invention: the hydraulic pump is a variable pump, and in step four, the total output flow of the system is kept stable by adjusting the swashplate angle of the variable pump.

[0015] As a further aspect of the present invention: the tracked engineering machinery is a tracked excavator, a tracked bulldozer, or a tracked crane.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. High recognition accuracy: It innovatively adopts a dual-parameter fusion criterion of "hydraulic pressure difference" and "track speed difference," using a pressure difference threshold (ΔP) to determine the accuracy. avg (×0.7) Effectively distinguishes between "uneven load" and "real slippage", minimizing the false judgment rate and achieving an accuracy rate of over 95%; 2. Fast response speed: By optimizing the sensor sampling frequency (10-20Hz) and the controller response cycle (≤50ms), millisecond-level rapid detection and intervention of slippage is achieved, which reduces the anti-slip response time by more than 60% compared with traditional solutions; 3. Balancing walking stability and work efficiency: To address unilateral slippage, a "one-to-one" flow coordination distribution strategy is adopted. While suppressing slippage, the power compensation of the non-slipping side is used to keep the overall machine walking speed highly stable (speed deviation ≤ 0.2km / h), avoiding work interruption and efficiency loss caused by simple braking. 4. Good system protection: The use of hydraulic flow regulation instead of mechanical braking as the main anti-slip means significantly reduces track wear and hydraulic shock, which helps to extend the service life of key components such as hydraulic motors, pumps, valves and tracks; 5. Strong adaptability to multiple road surfaces: By pre-storing feature threshold mapping tables for different road surfaces, the system can automatically identify and adapt to the current road surface, while also retaining the manual priority mode, which greatly enhances the applicability and robustness under complex and unknown working conditions. Attached Figure Description

[0017] Figure 1 This is a structural principle block diagram of the hydraulic-walking coordinated anti-slip control system according to one embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the overall flow of the control method described in one embodiment of the present invention. Detailed Implementation

[0019] The technical solution of this application will be further described in detail below with reference to specific embodiments.

[0020] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Example 1

[0021] Please see Figure 1 The hydraulic-walking coordinated anti-skid control system of this embodiment includes: a controller (ECU), a variable displacement hydraulic pump, a left track hydraulic motor and control valve, and a right track hydraulic motor and control valve. Pressure sensors (four in total) are installed at the inlet and outlet ports of the left and right hydraulic motors to detect the inlet and outlet pressures P1, P2, P3, and P4. Speed ​​sensors (two in total) are installed on the drive wheels of the left and right tracks to detect the speeds n1 and n2. The system also includes an overflow valve and an alarm device. The controller is electrically connected to all sensors, control valves, the variable displacement pump's regulating mechanism, and the alarm device.

[0022] Combination Figure 2 The control method in this embodiment is executed according to the following process: Initialization and real-time acquisition: After the system is powered on, the controller continuously acquires signals from all pressure and speed sensors at a frequency of 15Hz.

[0023] Parameter calculation: The controller calculates the pressure difference ΔP1 = P1 - P2 of the left track, the pressure difference ΔP2 = P3 - P4 of the right track, and the average pressure difference ΔP. avg =(ΔP1+ΔP2) / 2. Simultaneously, calculate the speed difference Δn=|n1-n2| and the speed difference percentage k=Δn / max(n1,n2).

[0024] Road surface type matching: The controller has pre-stored the mapping relationships shown in Table 1. Assume the currently calculated ΔP... avg If the pressure is 10MPa, the system will automatically match it as "gravel road surface" and call the corresponding speed difference ratio threshold k0=12%.

[0025] Table 1: Examples of Mapping Between Road Surface Type and Threshold Road surface type Pressure differential threshold range (MPa) <![CDATA[Rotation speed difference ratio threshold k0]]> muddy road 3-8 8% gravel road 8-15 12% Slope road surface 15-25 10% Slippage determination: Assume that at this time, k=15% and ΔP1=6MPa (less than ΔP). avg (×0.7=7MPa). Since k>12% and ΔP1<7MPa, the slippage condition is met, so it is determined that the left track slipped.

[0026] Coordinated control execution (one-sided slippage case): The controller immediately (response time < 50ms) sends a command to the left track control valve to reduce its opening by 20%, thereby reducing the flow rate of the left track and lowering the target speed to n1' = n1 × (1 - k / (2 × k0)) to suppress slippage.

[0027] At the same time, a command is sent to the right track control valve to increase its opening by 12%, thereby increasing the flow rate of the right track and raising the target speed to n2'=n2×(1+k / (2×k0)) to compensate for the power.

[0028] The controller synchronously adjusts the swashplate angle of the variable pump to ensure that the sum of the instantaneous flow rates of the left and right motors is basically consistent with that before slippage, thereby controlling the overall speed fluctuation within ±0.2km / h.

[0029] Status Monitoring and Exit: The controller continuously monitors parameters. If, for the next 3 consecutive seconds, the k value is consistently ≤9.6% (0.8×12%), and both ΔP1 and ΔP2 are ≥8MPa (0.8×10MPa), the adhesion conditions are considered to have improved. The controller smoothly restores the control valve opening and pump discharge to their pre-anti-slip state and exits the anti-slip mode.

[0030] Example 2 If in step 4, it is found that k > k0, and both ΔP1 and ΔP2 are less than ΔP avg If the value is ×0.7, it is determined to be slippage on both sides. The controller will then execute: S1. Simultaneously reduce the opening of the left and right track control valves by 15% to reduce the flow on both sides and prevent slippage from worsening. S2. Increase the set pressure of the system overflow valve by 6% to enhance the track's grip on the ground; S3. At the same time, send an audible and visual alarm signal to the dashboard to remind the operator to pay attention to the road conditions and suggest appropriately reducing the input of the travel control lever; S4. The exit conditions are the same as in Example 1.

[0031] In one embodiment of the present invention, the operator can, based on experience, force the selection of a road surface mode (such as "mud mode") via a button in the cab. In this case, the system will directly use the manually selected threshold instead of performing automatic matching.

[0032] Alternatively, the hydraulic pump can be another type of variable pump or fixed displacement pump combined with a proportional valve, as long as it can achieve stable regulation of the total flow rate.

[0033] The preset duration (e.g., 3 seconds) and proportional coefficient (e.g., 0.7, 0.8) for continuous judgment can be optimized and adjusted according to the specific model and control performance.

[0034] This hydraulic-walking coordinated anti-slip control method for tracked engineering machinery innovatively adopts a dual-parameter fusion criterion of "hydraulic pressure difference" and "track speed difference," using a pressure difference threshold (ΔP) as the basis for the judgment. avg (×0.7) Effectively distinguishes between "uneven load" and "real slippage," minimizing the false judgment rate and achieving an accuracy rate of over 95%. By optimizing the sensor sampling frequency (10-20Hz) and controller response cycle (≤50ms), millisecond-level rapid detection and intervention of slippage is achieved, reducing the anti-slip response time by more than 60% compared to traditional solutions. For unilateral slippage, a "one-to-one" flow coordination distribution strategy is adopted to suppress slippage while utilizing power compensation on the non-slip side, keeping the overall machine travel speed highly stable (speed deviation ≤0.2km / h), avoiding work interruptions and efficiency losses caused by simple braking. Using hydraulic flow regulation instead of mechanical braking as the main anti-slip method significantly reduces track wear and hydraulic shock, which helps extend the service life of key components such as hydraulic motors, pumps, valves, and tracks. By pre-storing feature threshold mapping tables for different road surfaces, the system can automatically identify and adapt to the current road surface, while also retaining a manual priority mode, greatly enhancing its applicability and robustness in complex and unknown working conditions.

[0035] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these should also be considered within the scope of protection of the present invention. These will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A hydraulic-walking coordinated anti-slip control method for tracked construction machinery, applied to tracked construction machinery including left / right track hydraulic motors, hydraulic pumps, controllers, and sensor groups, characterized in that, Includes the following steps: Step 1: Parameter Acquisition and Calculation: The controller acquires real-time data from pressure sensors installed at the inlet and outlet of the hydraulic motors of the left and right tracks, and calculates the pressure differences ΔP1 and ΔP2 between the inlet and outlet of the hydraulic motors of the left and right tracks, as well as their average value ΔP. avg Simultaneously, data from the speed sensors installed on the left and right track drive wheels are collected to obtain the left and right track speeds n1 and n2, and the track speed difference Δn=|n1-n2| and the speed difference ratio k=Δn / max(n1,n2) are calculated. Step 2, Road surface identification and threshold matching: The controller has a pre-stored mapping relationship of "pressure difference threshold range - speed difference ratio threshold" for several typical low-adhesion road surfaces. Based on the real-time calculated ΔPavg, the current road surface type and the corresponding speed difference ratio threshold k0 are matched. Step 3, Slippage Determination: When the percentage of the rotational speed difference k is greater than the threshold k0 of the current road surface type, and the pressure difference ΔP1 of the left track hydraulic motor or the pressure difference ΔP2 of the right track hydraulic motor is less than the average value ΔP avg When the value is 0.7 times the value, it is determined that the corresponding track has slipped; Step 4, Cooperative Anti-slip Control: If it is determined that the slippage is on one side of the track, the flow rate of the hydraulic motor on the slipping side is reduced, the flow rate of the hydraulic motor on the non-slipping side is increased, and the hydraulic pump is adjusted to maintain a stable total output flow rate of the system; if it is determined that the slippage is on both sides of the track, the flow rate of the hydraulic motors on both sides is reduced simultaneously, the working pressure of the hydraulic system is increased, and an alarm is triggered at the same time. Step 5, Exit and Resume: When the percentage of the rotational speed difference k is less than or equal to 0.8 × k0 within a continuously preset time period, and both ΔP1 and ΔP2 are greater than or equal to 0.8 × ΔP avg When the road surface adhesion is restored, the controller controls each actuator to return to its initial state before anti-skid control.

2. The hydraulic-walking coordinated anti-slip control method for tracked engineering machinery according to claim 1, characterized in that, The typical low-adhesion road surface includes at least muddy road surfaces, gravel road surfaces, and sloping road surfaces; among which... The pressure difference threshold range corresponding to the muddy road surface is 3-8 MPa, and the speed difference percentage threshold k0 is 8%; The pressure difference threshold range corresponding to the gravel road surface is 8-15MPa, and the speed difference ratio threshold k0 is 12%. The pressure difference threshold range corresponding to the slope road surface is 15-25MPa, and the speed difference ratio threshold k0 is 10%.

3. The hydraulic-walking coordinated anti-slip control method for tracked engineering machinery according to claim 1, characterized in that, The sampling frequency of the sensor group is 10-20Hz, and the command response time of the controller is ≤50ms.

4. The hydraulic-walking coordinated anti-slip control method for tracked engineering machinery according to claim 1, characterized in that, When one track slips, reduce the flow rate of the hydraulic motor on the slipping side by 15-25%, and increase the flow rate of the hydraulic motor on the non-slipping side by 10-15%.

5. The hydraulic-walking coordinated anti-slip control method for tracked engineering machinery according to claim 1, characterized in that, When both tracks slip, reduce the flow rate of both hydraulic motors by 10-20% simultaneously and increase the opening pressure of the hydraulic system relief valve by 5-8%.

6. The hydraulic-walking coordinated anti-slip control method for tracked engineering machinery according to claim 1, characterized in that, The controller also supports receiving road surface type instructions manually input by the operator, and the priority of manual instructions is higher than the automatic recognition results in step two.

7. The hydraulic-walking coordinated anti-slip control method for tracked engineering machinery according to claim 1, characterized in that, The hydraulic pump is a variable pump. In step four, the swashplate angle of the variable pump is adjusted to maintain a stable total output flow of the system.

8. The hydraulic-walking coordinated anti-slip control method for tracked engineering machinery according to claim 1, characterized in that, The tracked construction machinery refers to tracked excavators, tracked bulldozers, or tracked cranes.

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