Torque distribution control method for a mine four-wheel wheel drive vehicle

Abstract

The present application belongs to the technical field of driving control of auxiliary transport equipment for mines, and aims to solve the problem that simple movement mechanism power adjustment cannot match complex driving conditions in the prior art. A torque distribution control method for a mine four-wheel wheel edge driving vehicle is provided, comprising the following steps: collecting vertical load information at each movement mechanism of the vehicle, and based on the vertical load information and total torque, performing first distribution of driving torque of each movement mechanism driver of the vehicle; collecting real-time slip ratio of each movement mechanism of the vehicle, and obtaining expected control torque of each movement mechanism driver; comparing the expected control torque of each movement mechanism driver with the driving torque after the first distribution, and performing second distribution of the driving torque of each movement mechanism driver of the vehicle; and performing third distribution of excess torque of the movement mechanism driver after output limiting. The present application can dynamically adjust the torque output of the movement mechanism driver, and realize optimal movement mechanism power adjustment.

Description

Technical Field

[0001] The present invention belongs to the technical field of drive control of mining auxiliary transport equipment, and in particular relates to a torque distribution control method for a mining four-wheel drive vehicle. Background Art

[0002] In recent years, the electrification of auxiliary transport equipment has become an inevitable development trend. Distributed, battery-powered wheel-driven auxiliary transport equipment has quietly emerged in domestic coal mines. However, wheel-driven systems currently only implement simple control, without coordinated control of multiple drive units. A simple control method based on equal torque is generally used. During field operations, slippage often leads to vehicle failures and severe wear of the moving mechanism. Furthermore, the vehicle's parasitic power is relatively high, resulting in a significant deviation between theoretical and actual ranges, often exceeding 30%, and a lack of relevant dynamics theory. Furthermore, due to the unique operating environment, coal mine auxiliary transport equipment generally utilizes heavy-duty, solid rubber or polyurethane moving mechanisms. Due to the lack of a relatively accurate moving mechanism model, vehicle dynamics research has remained limited to the theoretical stage. Optimal torque distribution among multiple drive units and vehicle slip control remain superficial and unapplicable in practice.

[0003] Articulated auxiliary transport equipment improves low-speed control and steering maneuverability, and has strong terrain adaptability. Because its steering structure eliminates the connection between the steering mechanisms of the moving parts, it can save space in the vehicle layout, increase the space utilization of the auxiliary transport equipment, and facilitate the layout of other components. Compared with its many advantages, it also has disadvantages: high steering power consumption, high wear of the moving parts, poor steering stability, and the need to improve the control precision of the auxiliary transport equipment movement. Summary of the Invention

[0004] In order to solve at least one of the above technical problems existing in the prior art, the present invention provides a torque distribution control method for a four-wheel drive mining vehicle.

[0005] The present invention is implemented by the following technical solution: a method for controlling torque distribution of a four-wheel drive mining vehicle, comprising the following steps:

[0006] Collecting the opening information of the vehicle's accelerator pedal, and obtaining the total torque currently required by the vehicle based on the opening information;

[0007] Collecting vertical load information at each moving mechanism of the vehicle, and performing a first distribution of driving torques of the drivers of each moving mechanism of the vehicle based on the vertical load information and the total torque;

[0008] Collecting the real-time slip rate of each moving mechanism of the vehicle, and obtaining the desired control torque of the driver of each moving mechanism based on a preset target slip rate and the real-time slip rate;

[0009] Comparing the desired control torque of each moving mechanism driver with the driving torque after the first distribution, and performing a second distribution of the driving torque of each moving mechanism driver of the vehicle based on the comparison result;

[0010] Based on the result of the second distribution, the excess torque of the mobile mechanism driver with output limitation is distributed for the third time and distributed to the remaining mobile mechanism drivers with insufficient torque, completing the final torque distribution of each mobile mechanism of the vehicle.

[0011] Preferably, the result of the first allocation is expressed as:

[0012]

[0013]

[0014]

[0015]

[0016] Where, 、 、 、 Respectively represent the driving torques required to be distributed to the left front wheel, right front wheel, left rear wheel, and right rear wheel drivers in the first driving torque distribution, 、 、 、 Represent the vertical loads of the left front wheel, right front wheel, left rear wheel, and right rear wheel respectively; , where Indicates the total torque currently required by the vehicle, Indicates the percentage of the current accelerator pedal opening to the total accelerator pedal opening. Indicates the total torque obtained by the vehicle when the accelerator pedal opening reaches 100%.

[0017] Preferably, the step of obtaining the desired control torque of each moving mechanism driver based on a preset target slip rate and the real-time slip rate includes:

[0018] After the vehicle starts moving, the real-time slip rates of the four moving mechanisms, namely the left front wheel, left rear wheel, right front wheel and right rear wheel, are calculated based on the moving mechanism slip rate controller.

[0019] The difference between the real-time slip rate and the preset target slip rate is used as the input of the mobile mechanism power adjustment controller;

[0020] The mobile mechanism power adjustment controller is based on PID control and calculates the expected control torque of each mobile mechanism driver.

[0021] Preferably, the desired control torque of each moving mechanism driver is expressed as:

[0022]

[0023]

[0024]

[0025]

[0026] Where, 、 、 、 They represent the desired control torques of the left front wheel, right front wheel, left rear wheel, and right rear wheel respectively according to the real-time slip rate of the moving mechanism. 、 、 Respectively represent the proportional coefficient, integral coefficient and differential coefficient of the PID algorithm;

[0027] 、 、 、 Where, 、 、 、 Respectively represent the difference between the target slip rate and the real-time slip rate of the left front wheel, right front wheel, left rear wheel, and right rear wheel, represents the target slip rate of the moving mechanism, 、 、 、 Respectively represent the real-time slip rates of the left front wheel, right front wheel, left rear wheel, and right rear wheel.

[0028] Preferably, in the second distribution, the smaller of the desired control torque of each moving mechanism driver and the corresponding driving torque after the first distribution is selected as the result of the second distribution:

[0029]

[0030]

[0031]

[0032]

[0033] Where, 、 、 、 They respectively represent the driving torque required to be distributed to the left front wheel, right front wheel, left rear wheel, and right rear wheel drives after the second distribution.

[0034] Preferably, the third allocation includes the following steps:

[0035] Subtracting the desired control torque from the driving torque of each moving mechanism driver after the first distribution to obtain a difference between the two;

[0036] The third distribution of torque is performed based on the difference between the two, the desired control torque of each moving mechanism driver, the driving torque after the first distribution, and the driving torque after the second distribution.

[0037] Preferably, the difference between the driving torque of each moving mechanism driver and the expected control torque after the first distribution is expressed as:

[0038]

[0039]

[0040]

[0041]

[0042] 、 、 、 Respectively represent the driving torque and expected control torque of the left front wheel, right front wheel, left rear wheel, and right rear wheel drives after the first distribution.

[0043] Preferably, the result of the third allocation is expressed as:

[0044]

[0045]

[0046]

[0047]

[0048] In the formula 、 、 、 They respectively represent the driving torques required to be distributed to the left front wheel, right front wheel, left rear wheel, and right rear wheel drives after the third distribution.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The present invention adopts a mobile mechanism power adjustment strategy. The mining wheel-side driven auxiliary transport equipment can significantly improve the driving stability, power and passability in the complex and changeable coal mine environment, reduce the wear of the mobile mechanism, extend the service life of the auxiliary transport equipment, and at the same time improve the working efficiency and safety.

[0051] The present invention has the following technical effects: realizing real-time status monitoring, integrating multiple sensors, and monitoring key parameters such as the load of the auxiliary transport equipment and the slip rate of each mobile mechanism in real time; completing the dynamic mobile mechanism power adjustment of the auxiliary transport equipment, and dynamically adjusting the torque output of the mobile mechanism driver according to the algorithm decision result to ensure the optimal traction and stability of the auxiliary transport equipment under complex road conditions; ensuring the working stability of the auxiliary transport equipment, ensuring that the auxiliary transport equipment can still travel safely when a single mobile mechanism driver fails, and adjusting the power adjustment of the remaining wheels through adaptive strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0053] Figure 1 It is a flow chart of the control process of the power adjustment of the moving mechanism;

[0054] Figure 2 This is a simulation model diagram of the power adjustment control system of the mobile mechanism of the mining wheel-driven auxiliary transport equipment;

[0055] Figure 3 This is a diagram showing the lateral load variation of the mobile mechanism of the auxiliary transport equipment when turning after using the strategy of the present invention;

[0056] Figure 4 This is a graph showing the change in slip rate of the mobile mechanism of the auxiliary transport equipment when turning after using the strategy of the present invention;

[0057] Figure 5 FIG. 4 is a diagram showing the torque variation of the drive under FTP75 working condition after using the strategy of the present invention. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present invention are clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other implementations derived by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0059] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention. It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity from several other entities, and do not necessarily require or imply any actual relationship or order between these entities.

[0060] The present invention provides an embodiment:

[0061] A method for controlling torque distribution of a four-wheel drive mining vehicle comprises the following steps:

[0062] The opening information of the vehicle's accelerator pedal is collected, and the total torque currently required by the vehicle is obtained based on the opening information; the vertical load information at each mobile mechanism of the vehicle is collected, and the driving torque of each mobile mechanism driver of the vehicle is distributed for the first time based on the vertical load information and the total torque; the real-time slip rate of each mobile mechanism of the vehicle is collected, and the expected control torque of each mobile mechanism driver is obtained based on the preset target slip rate and the real-time slip rate; the expected control torque of each mobile mechanism driver is compared with the driving torque after the first distribution, and the driving torque of each mobile mechanism driver of the vehicle is distributed for the second time based on the comparison result; based on the result of the second distribution, the excess torque of the mobile mechanism driver with output limitation is distributed for the third time, and it is distributed to the remaining mobile mechanism drivers with insufficient torque, thereby completing the final torque distribution of each mobile mechanism of the vehicle.

[0063] In the present invention, the mobile mechanism power adjustment control system specifically includes an operator model, an auxiliary transport equipment model, a mobile mechanism slip rate controller and a mobile mechanism power adjustment controller. The control process is shown in the attached figure. Figure 1 The auxiliary transport equipment is a vehicle, and the moving mechanism includes a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel.

[0064] First, based on the operator's input on the accelerator pedal, the total torque currently required by the auxiliary transport equipment is obtained, which is expressed as follows:

[0065] , where Indicates the total torque currently required by the vehicle, Indicates the percentage of the current accelerator pedal opening to the total accelerator pedal opening. Indicates the total torque obtained by the vehicle when the accelerator pedal opening reaches 100%.

[0066] Then, based on the vertical load conditions of each moving mechanism of the auxiliary transport equipment, the output torque that should be distributed to each driver is calculated. The result of the first distribution is expressed as:

[0067]

[0068]

[0069]

[0070]

[0071] Where, 、 、 、 Respectively represent the driving torques required to be distributed to the left front wheel, right front wheel, left rear wheel, and right rear wheel drivers in the first driving torque distribution, 、 、 、 Represent the vertical loads of the left front wheel, right front wheel, left rear wheel, and right rear wheel respectively;

[0072] After the vehicle starts moving, the real-time slip rates of the four moving mechanisms (left front wheel, left rear wheel, right front wheel, and right rear wheel) are calculated based on the moving mechanism slip rate controller. The difference between the real-time slip rate and the preset target slip rate is used as the input of the moving mechanism power adjustment controller, which is expressed as follows:

[0073] 、 、 、 ;

[0074] Where, 、 、 、 Respectively represent the difference between the target slip rate and the real-time slip rate of the left front wheel, right front wheel, left rear wheel, and right rear wheel, represents the target slip rate of the moving mechanism, 、 、 、 Respectively represent the real-time slip rates of the left front wheel, right front wheel, left rear wheel, and right rear wheel.

[0075] The mobile mechanism power adjustment controller is based on PID control and calculates the expected control torque of each mobile mechanism driver:

[0076]

[0077]

[0078]

[0079]

[0080] Where, 、 、 、 They represent the desired control torques of the left front wheel, right front wheel, left rear wheel, and right rear wheel respectively according to the real-time slip rate of the moving mechanism. 、 、 They represent the proportional coefficient, integral coefficient and differential coefficient of the PID algorithm respectively.

[0081] During the driving process of auxiliary transport equipment, the priority of the torque required by the operator should be higher than the torque required by the drive unit. Therefore, the expected control torque is compared with the torque required by the operator to obtain the result of the second power adjustment of the auxiliary transport equipment's moving mechanism.

[0082] In the second distribution, the smaller of the desired control torque of each mobile mechanism driver and the corresponding driving torque after the first distribution is selected as the result of the second distribution:

[0083]

[0084]

[0085]

[0086]

[0087] Where, 、 、 、 They respectively represent the driving torques required to be distributed to the left front wheel, right front wheel, left rear wheel, and right rear wheel drives after the second distribution.

[0088] After two distributions, there is a situation: the output torque demand of a part of the mobile mechanism power adjustment controller is less than the torque one-time distribution result of the corresponding driver, thereby outputting the calculated torque of the mobile mechanism power adjustment controller; while the output torque demand of another part of the mobile mechanism power adjustment controller is greater than the torque one-time distribution result of the corresponding driver, thereby limiting the output torque of the mobile mechanism power adjustment controller and outputting the torque one-time distribution result of the driver.

[0089] At this point, some drives are under-driven, while others are limited. To ensure the operator's intended operation is performed while maximizing the use of drive unit torque and improving the overall drive performance of the auxiliary equipment, the excess output limit is adjusted and distributed to the under-driven drive units, completing the third torque distribution.

[0090] The third allocation includes the following steps:

[0091] Subtract the desired control torque from the driving torque of each moving mechanism driver after the first distribution to obtain the difference between the two;

[0092] The third distribution of torque is performed based on the difference between the two, the desired control torque of each moving mechanism driver, the driving torque after the first distribution, and the driving torque after the second distribution.

[0093] The difference between the driving torque of each mobile mechanism driver and the expected control torque after the first distribution is expressed as:

[0094]

[0095]

[0096]

[0097]

[0098] 、 、 、 Respectively represent the driving torque and expected control torque of the left front wheel, right front wheel, left rear wheel, and right rear wheel drives after the first distribution.

[0099] The result of the third allocation is expressed as:

[0100]

[0101]

[0102]

[0103]

[0104] In the formula 、 、 、 They respectively represent the driving torques required to be distributed to the left front wheel, right front wheel, left rear wheel, and right rear wheel drives after the third distribution.

[0105] To describe the technical contents of the present invention in detail, Figures 2 to 5 The present invention will be described in detail.

[0106] Establish a simulation model of the power adjustment control system of the mobile mechanism of the mine wheel-driven auxiliary transport equipment. Figure 2 As shown, the system includes modules for calculating the yaw rate of the auxiliary transport equipment, the longitudinal velocity of the vehicle body, the lateral velocity of the vehicle body, the lateral and longitudinal forces of the mobile mechanism, and the slip rate of the mobile mechanism. Using the proposed mobile mechanism dynamic adjustment strategy, the vertical load and slip rate of the mobile mechanism are calculated using the auxiliary transport equipment simulation model and input into the controller to complete a mobile mechanism dynamic adjustment control.

[0107] After the auxiliary transport equipment is started, at t=1s, the front wheel steering angle is given to be 1rad, and the Figure 3 The figure shows the change of vertical load of the mobile mechanism. The lateral load of the front wheel changes suddenly, and the load of the rear wheel changes accordingly. Figure 4 The variation of the slip rate of the moving mechanism is shown in the figure. The slip rate of the moving mechanism is the highest in the middle of the turn. The simulation condition is set to FTP75 condition. The variation of the torque of the four drives is shown in the figure. Figure 5 shown.

[0108] The foregoing description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be readily conceived by a person skilled in the art within the technical scope disclosed herein should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for controlling torque distribution of a four-wheel drive mining vehicle, characterized in that: The following steps are involved: Collecting the opening information of the vehicle's accelerator pedal, and obtaining the total torque currently required by the vehicle based on the opening information; Collecting vertical load information at each moving mechanism of the vehicle, and performing a first distribution of driving torques of the drivers of each moving mechanism of the vehicle based on the vertical load information and the total torque; Collecting the real-time slip rate of each moving mechanism of the vehicle, and obtaining the desired control torque of the driver of each moving mechanism based on a preset target slip rate and the real-time slip rate; The step of obtaining the desired control torque of each mobile mechanism driver based on the preset target slip rate and the real-time slip rate includes: after the vehicle starts moving, calculating the real-time slip rate of the four mobile mechanisms of the left front wheel, the left rear wheel, the right front wheel, and the right rear wheel based on the mobile mechanism slip rate controller; using the difference between the real-time slip rate and the preset target slip rate as the input of the mobile mechanism power adjustment controller; the mobile mechanism power adjustment controller calculating the desired control torque of each mobile mechanism driver based on PID control; The desired control torque of each mobile mechanism driver is compared with the driving torque after the first distribution, and the driving torque of each mobile mechanism driver of the vehicle is secondarily distributed based on the comparison result; in the second distribution, the smaller of the desired control torque of each mobile mechanism driver and the corresponding driving torque after the first distribution is selected as the result of the second distribution: Where, 、 、 、 Respectively represent the driving torques required to be distributed to the left front wheel, right front wheel, left rear wheel, and right rear wheel drives after the second distribution; 、 、 、 Respectively represent the driving torques required to be distributed to the left front wheel, right front wheel, left rear wheel, and right rear wheel drivers in the first driving torque distribution; 、 、 、 They represent the desired control torques of the left front wheel, right front wheel, left rear wheel, and right rear wheel respectively according to the real-time slip rate of the moving mechanism; Based on the result of the second distribution, the excess torque of the mobile mechanism driver with output limitation is distributed for the third time and distributed to the remaining mobile mechanism drivers with insufficient torque, thereby completing the final torque distribution of each mobile mechanism of the vehicle; the third distribution includes the following steps: subtracting the desired control torque from the driving torque of each mobile mechanism driver after the first distribution to obtain the difference between the two; the difference between the driving torque of each mobile mechanism driver and the desired control torque after the first distribution is expressed as: 、 、 、 Respectively represent the errors between the driving torque and the desired control torque of the left front wheel, right front wheel, left rear wheel, and right rear wheel drivers after the first distribution; The third distribution of torque is performed based on the difference between the two, the desired control torque of each mobile mechanism driver, the driving torque after the first distribution, and the driving torque after the second distribution. The result of the third distribution is expressed as: In the formula 、 、 、 They respectively represent the driving torques required to be distributed to the left front wheel, right front wheel, left rear wheel, and right rear wheel drives after the third distribution.

2. The method for controlling torque distribution of a four-wheel drive mining vehicle according to claim 1, characterized in that: The result of the first allocation is expressed as: 、 、 、 Represent the vertical loads of the left front wheel, right front wheel, left rear wheel, and right rear wheel respectively; , where Indicates the total torque currently required by the vehicle, Indicates the percentage of the current accelerator pedal opening to the total accelerator pedal opening. Indicates the total torque obtained by the vehicle when the accelerator pedal opening reaches 100%.

3. The method for controlling torque distribution of a four-wheel drive mining vehicle according to claim 2, characterized in that: The desired control torque of each moving mechanism driver is expressed as: Where, 、 、 Respectively represent the proportional coefficient, integral coefficient and differential coefficient of the PID algorithm; 、 、 、 Where, 、 、 、 Respectively represent the difference between the target slip rate and the real-time slip rate of the left front wheel, right front wheel, left rear wheel, and right rear wheel, represents the target slip rate of the moving mechanism, 、 、 、 Respectively represent the real-time slip rates of the left front wheel, right front wheel, left rear wheel, and right rear wheel.

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