Torque distribution control method for mining four-wheel rim drive vehicle

Abstract

The invention belongs to the technical field of driving control of mining auxiliary transportation equipment, and aims to solve the problem that power adjustment of a simple moving mechanism cannot be matched with complex driving working conditions in the prior art. The invention provides a torque distribution control method for a mining four-wheel hub-driven vehicle, which comprises the following steps of: acquiring vertical load information at each moving mechanism of the vehicle, and distributing the driving torque of each moving mechanism driver of the vehicle for the first time on the basis of the vertical load information and a total torque; the real-time slip rate of each moving mechanism of the vehicle is collected, and the expected control torque of a driver of each moving mechanism is obtained; the expected control torque of each moving mechanism driver is compared with the driving torque distributed for the first time, and the driving torque of each moving mechanism driver of the vehicle is distributed for the second time; and the redundant torque of the output amplitude-limited moving mechanism driver is distributed for the third time. According to the invention, the torque output of the moving mechanism driver can be dynamically adjusted, and the optimal moving mechanism power adjustment is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of driving control of auxiliary transportation equipment for mines, and particularly relates to a torque distribution control method for a four-wheel in-wheel motor drive vehicle for mines. Background Art

[0002] In recent years, the electrification of auxiliary transportation equipment has become an inevitable development trend, and distributed in-wheel motor drive operation auxiliary transportation equipment powered by storage batteries has quietly emerged in domestic coal mines. However, the in-wheel motor drive system has only achieved simple control at present, and multiple drive units have not been coordinated. Generally, a simple control method of equal torque setting is adopted. During on-site operation, there are often phenomena such as inability to start due to slipping, and the moving mechanism wears relatively seriously. Secondly, the parasitic power of the whole vehicle is relatively large, and there is a large deviation between the theoretical endurance and the actual endurance, generally with an error of more than 30%. There is a lack of relevant dynamics theory guidance. At the same time, due to the particularity of the use environment, the auxiliary transportation equipment for coal mine operation generally adopts rubber or polyurethane solid heavy moving mechanisms. Due to the lack of a relatively accurate moving mechanism model, the dynamic research of the whole vehicle only stays at the theoretical stage, and the optimal distribution of the driving torque between multiple drive units and the slip rate control of the whole vehicle are even only on the surface and cannot be used in practice.

[0003] The articulated structure auxiliary transportation equipment improves the maneuverability and steering mobility of the auxiliary transportation equipment at low speeds and has strong terrain adaptability. Since its steering type cancels the connection of the steering mechanism between the moving mechanisms, the layout space of the whole vehicle can be saved, the space utilization rate of the auxiliary transportation equipment can be increased, and it is beneficial to the layout of other components. Compared with many advantages, it also has disadvantages: the power consumed by steering is large, the moving mechanism wears greatly, the steering stability is poor, and it is more necessary to improve the control accuracy of the movement of the auxiliary transportation equipment. Summary of the Invention

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

[0005] The invention is realized by adopting the following technical scheme: A torque distribution control method for a four-wheel in-wheel motor drive vehicle for mines, comprising the following steps:

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

[0007] Collect the vertical load information at each moving mechanism of the vehicle, and perform the first distribution of the driving torque of the vehicle's moving mechanism drivers based on the vertical load information and the total torque;

[0008] Collect the real-time slip ratio of each moving mechanism of the vehicle, and obtain the desired control torque of each moving mechanism driver based on the preset target slip ratio and the real-time slip ratio;

[0009] Compare the desired control torque of each moving mechanism driver with the driving torque after the first distribution, and perform a second distribution on 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, perform a third distribution on the excess torque of the moving mechanism driver with output limiting, and distribute it to the remaining moving mechanism drivers with insufficient torque to complete the final torque distribution of each moving mechanism of the vehicle.

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

[0012]

[0013] In the formula, T fl1_1 , T fr1_1 , T rl1_1 , T rr1_1 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, F z1 , F z2 , F z3 , F z4 respectively represent the vertical loads of the left front wheel, right front wheel, left rear wheel, and right rear wheel; T veh = δT max , where T veh represents the total torque required by the vehicle at present, δ represents the percentage of the current accelerator pedal opening to the total accelerator pedal opening, and T max represents the total torque obtained by the vehicle when the accelerator pedal opening reaches 100%.

[0014] Preferably, the steps of obtaining the desired control torque of each moving mechanism driver based on the preset target slip ratio and the real-time slip ratio include:

[0015] After the vehicle starts to drive, calculate the real-time slip ratios of the four moving mechanisms of the left front wheel, left rear wheel, right front wheel, and right rear wheel based on the moving mechanism slip ratio controller;

[0016] Use the difference between the real-time slip ratio and the preset target slip ratio as the input of the moving mechanism power adjustment controller;

[0017] The moving mechanism power adjustment controller calculates the desired control torque of each moving mechanism driver based on PID control.

[0018] Preferably, the desired control torque of each moving mechanism driver is expressed as:

[0019]

[0020]

[0021] In the formula, T fl1_2 , T fr1_2 , T rl1_2 , T rr1_2 respectively represent the expected control torques of the left front wheel, right front wheel, left rear wheel, and right rear wheel obtained according to the actual slip ratio of the moving mechanism, and k p , k i , k d respectively represent the proportional coefficient, integral coefficient, and differential coefficient of the PID algorithm;

[0022] S e1 = S0 - S1, S e2 = S0 - S2, S e3 = S0 - S3, S e4 = S0 - S4; In the formula, S e1 , S e2 , S e3 , S e4

[0023] respectively represent the differences between the target slip ratios and the actual slip ratios of the left front wheel, right front wheel, left rear wheel, and right rear wheel. S0 represents the target slip ratio of the moving mechanism, and S1, S2, S3, and S4 respectively represent the actual slip ratios of the left front wheel, right front wheel, left rear wheel, and right rear wheel.

[0024] Preferably, in the second allocation, the smaller one of the expected control torque of each moving mechanism driver and the corresponding driving torque after the first allocation is selected as the result of the second allocation:

[0025] T fl2 = min(T fl1_1 , T fl1_2 )

[0026] T fr2 = min(T fr1_1 , T fr1_2 )

[0027] T rl2 = min(T rl1_1 , T rl1_2 )

[0028] T rr2 = min(T rr1_1 , T rr1_2 )

[0029] In the formula, T fl2 , T fr2, T rl2 , T rr2 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.

[0030] Preferably, the third distribution includes the following steps:

[0031] Subtract the desired control torque from the driving torque of each mobile mechanism drive after the first distribution to obtain the difference between the two;

[0032] Based on the difference between the two, the desired control torque of each mobile mechanism drive, the driving torque after the first distribution, and the driving torque after the second distribution, perform the third distribution of the torque.

[0033] Preferably, the difference between the driving torque of each mobile mechanism drive and the desired control torque after the first distribution is expressed as:

[0034] T e1 = T fl1_1 - T fl1_2

[0035] T e2 = T fr1_1 - T fr1_2

[0036] T e3 = T rl1_1 - T rl1_2

[0037] T e4 = T rr1_1 - T rr1_2

[0038]

[0039] where n is the number of T ei > 0, and T e1 , T e2 , T e3 , T e4 respectively represent the driving torques and desired control torques of the left front wheel, right front wheel, left rear wheel, and right rear wheel drives after the first distribution.

[0040] Preferably, the result of the third distribution is expressed as:

[0041]

[0042] where T fl3 , T fr3 , T rl3 , T rr3They 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.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] The present invention adopts a power adjustment strategy for the mobile mechanism, enabling the mine wheel-side drive auxiliary transportation equipment to significantly improve the driving stability, power performance, and passability in the complex and changeable coal mine environment, reducing the wear of the mobile mechanism, extending the service life of the auxiliary transportation equipment, and simultaneously enhancing the operation efficiency and safety.

[0045] The present invention has the following technical effects: realizing real-time status monitoring, integrating multiple sensors to monitor key parameters such as the load of the auxiliary transportation equipment and the slip ratio of each mobile mechanism in real time; completing the dynamic power adjustment of the mobile mechanism of the auxiliary transportation equipment, dynamically adjusting the torque output of the mobile mechanism drive according to the algorithm decision result to ensure the best traction and stability of the auxiliary transportation equipment under complex road conditions; ensuring the working stability of the auxiliary transportation equipment, ensuring that the auxiliary transportation equipment can still drive safely when a single mobile mechanism drive fails, and adjusting the power of the remaining wheels through an adaptive strategy. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0047] Figure 1 is the flow block diagram of the power adjustment control of the mobile mechanism;

[0048] Figure 2 is the simulation model diagram of the power adjustment control system of the mobile mechanism of the mine wheel-side drive auxiliary transportation equipment built;

[0049] Figure 3 is the diagram of the lateral load change of the mobile mechanism when the auxiliary transportation equipment turns after using the strategy of the present invention;

[0050] Figure 4 is the diagram of the slip ratio change of the mobile mechanism when the auxiliary transportation equipment turns after using the strategy of the present invention;

[0051] Figure 5 is the diagram of the torque change of the drive under the FTP75 working condition after using the strategy of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] Combined with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation manners obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present invention.

[0053] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those who are familiar with this technology to understand and read, and are not used to limit the limited conditions under which the present invention can be implemented. Therefore, they do not have any technical substance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should fall within the scope covered by the technical content disclosed in 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.

[0054] The present invention provides an embodiment:

[0055] A torque distribution control method for a four-wheel wheel-side drive vehicle used in mines, comprising the following steps:

[0056] Collect the opening degree information of the vehicle's accelerator pedal, and obtain the total torque currently required by the vehicle based on the opening degree information; collect the vertical load information at each moving mechanism of the vehicle, and perform a first distribution of the driving torque of the drivers of each moving mechanism of the vehicle based on the vertical load information and the total torque; collect the real-time slip ratio of each moving mechanism of the vehicle, and obtain the desired control torque of the drivers of each moving mechanism based on the preset target slip ratio and the real-time slip ratio; compare the desired control torque of the drivers of each moving mechanism with the driving torque after the first distribution, and perform a second distribution of the driving torque of the drivers of each moving mechanism of the vehicle based on the comparison result; based on the result of the second distribution, perform a third distribution of the excess torque of the moving mechanism driver with output limiting, and distribute it to the other moving mechanism drivers with insufficient torque to complete the final torque distribution of each moving mechanism of the vehicle.

[0057] In the present invention, the moving mechanism power adjustment control system specifically includes an operator model, an auxiliary transportation equipment model, a moving mechanism slip ratio controller, and a moving mechanism power adjustment controller, and the control flow is as shown in the appendix Figure 1 shown. The auxiliary transportation equipment is the vehicle, and the moving mechanisms include the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel.

[0058] First, according to the input of the operator to the accelerator pedal, obtain the total torque currently required by the auxiliary transportation equipment, which is expressed as follows:

[0059] T veh = δT max , where T veh represents the total torque currently required by the vehicle, δ represents the percentage of the current accelerator pedal opening to the total accelerator pedal opening, and T max represents the total torque obtained by the vehicle when the accelerator pedal opening reaches 100%.

[0060] After that, according to the vertical load conditions of the current moving mechanisms of the auxiliary transportation equipment, calculate the output torque that should be distributed to each driver. The result of the first distribution is expressed as:

[0061]

[0062] In the formula, T fl1_1 , T fr1_1 , T rl1_1 , T rr1_1 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. F z1 , F z2 , F z3 , F z4 respectively represent the vertical loads of the left front wheel, right front wheel, left rear wheel, and right rear wheel;

[0063] After the vehicle starts to drive, calculate the real-time slip ratios of the four moving mechanisms of the left front wheel, left rear wheel, right front wheel, and right rear wheel based on the moving mechanism slip ratio controller; use the difference between the real-time slip ratio and the preset target slip ratio as the input of the moving mechanism power adjustment controller, which is expressed as follows:

[0064] S e1 = S0 - S1, S e2 = S0 - S2, S e3 = S0 - S3, S e4 = S0 - S4;

[0065] In the formula, S e1 , S e2 , S e3 , S e4 respectively represent the differences between the target slip ratios and the real-time slip ratios of the left front wheel, right front wheel, left rear wheel, and right rear wheel. S0 represents the target slip ratio of the moving mechanism, and S1, S2, S3, and S4 respectively represent the real-time slip ratios of the left front wheel, right front wheel, left rear wheel, and right rear wheel.

[0066] The moving mechanism power adjustment controller calculates the desired control torque of each moving mechanism driver based on PID control:

[0067]

[0068] Where, T fl1_2 , T fr1_2 , T rl1_2 , T rr1_2 respectively represent the desired control torques obtained from the real-time slip ratios of the left front wheel, right front wheel, left rear wheel, and right rear wheel according to the moving mechanism, and k p , k i , k d respectively represent the proportional coefficient, integral coefficient, and differential coefficient of the PID algorithm.

[0069] During the driving process of the auxiliary transportation equipment, the priority of the torque required by the operator should be higher than the torque required by the drive unit. Therefore, the desired control torque is compared with the torque required by the operator to obtain the result of the second power adjustment of the moving mechanism of the auxiliary transportation equipment.

[0070] In the second distribution, the smaller one 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:

[0071] T fl2 = min(T fl1_1 , T fl1_2 )

[0072] T fr2 = min(T fr1_1 , T fr1_2 )

[0073] T rl2 = min(T rl1_1 , T rl1_2 )

[0074] T rr2 = min(T rr1_1 , T rr1_2 )

[0075] Where, T fl2 , T fr2 , T rl2 , T rr2 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 after the second distribution.

[0076] After two distributions, there is a situation: for some moving mechanism power adjustment controllers, the output torque requirement is less than the torque first distribution result of the corresponding driver, so the calculated torque of the moving mechanism power adjustment controller is output; for some other moving mechanism power adjustment controllers, the output torque requirement is greater than the torque first distribution result of the corresponding driver, so the output torque of the moving mechanism power adjustment controller is limited, and the torque first distribution result of the driver is output.

[0077] At this time, the drive output of some drivers is insufficient, and the output of some other drivers is limited. To ensure that the operator's operating intention is followed while maximizing the use of the torque of the drive unit and improving the overall drive performance of the auxiliary transportation equipment, the redundant part of the output limit is adjusted and distributed to the drive units with insufficient drive to complete the third torque distribution.

[0078] The third distribution includes the following steps:

[0079] Subtract the desired control torque from the drive torque of each mobile mechanism driver after the first distribution to obtain the difference between the two;

[0080] Based on the difference between the two, the desired control torque of each mobile mechanism driver, the drive torque after the first distribution, and the drive torque after the second distribution, perform the third torque distribution.

[0081] The difference between the drive torque and the desired control torque of each mobile mechanism driver after the first distribution is expressed as:

[0082] T e1 = T fl1_1 - T fl1_2

[0083] T e2 = T fr1_1 - T fr1_2

[0084] T e3 = T rl1_1 - T rl1_2

[0085] T e4 = T rr1_1 - T rr1_2

[0086]

[0087] In the formula, n is the number of T ei > 0, and T e1 , T e2 , T e3 , T e4 respectively represent the drive 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.

[0088] The result of the third distribution is expressed as:

[0089]

[0090] In the formula, T fl3 , T fr3 , T rl3 , T rr3They 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.

[0091] To describe the technical content of the present invention in detail, the following combines the attached Figures 2 to 5 The present invention will be described in detail.

[0092] A simulation model of the power adjustment control system for the moving mechanism of the mine-used in-wheel drive auxiliary transportation equipment is established. The model is as shown in the attached Figure 2 figure, and includes an auxiliary transportation equipment yaw angular velocity calculation module, a vehicle body longitudinal speed calculation module, a vehicle body lateral speed calculation module, a moving mechanism lateral force and longitudinal force calculation module, and a moving mechanism slip ratio calculation module. Using the moving mechanism power adjustment strategy proposed by the present invention, the vertical load and slip ratio of the moving mechanism are calculated through the auxiliary transportation equipment simulation model, and input to the controller to complete a moving mechanism power adjustment control.

[0093] After the auxiliary transportation equipment starts, at t = 1 s, the front wheel steering angle is given as 1 rad. The attached Figure 3 figure shows the change of the vertical load of the moving mechanism. The lateral load of the front wheel changes suddenly, and the load of the rear wheel changes accordingly; the attached Figure 4 figure shows the change of the slip ratio of the moving mechanism. The slip ratio of the moving mechanism is the highest in the middle of the turn. The simulation working condition is set as the FTP75 working condition, and the torque change conditions of the four drives are as shown in the attached Figure 5 figure.

[0094] As mentioned above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for controlling torque distribution of a mining four-wheel drive vehicle, characterized in that: The following steps are involved: Collecting the opening information of the vehicle 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 the driving torque 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; 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; 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.

2. The method for controlling torque distribution of a mining four-wheel drive vehicle according to claim 1, characterized in that: The result of the first allocation is expressed as: Where, T fl1_1 、T fr1_1 、T rl1_1 、T rr1_1 They represent the driving torques 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, respectively. z1 、F z2 、F z3 、F z4 Respectively represent the vertical loads of the left front wheel, right front wheel, left rear wheel, and right rear wheel; T veh =δT max , where T veh represents the total torque currently required by the vehicle, δ represents the percentage of the current accelerator pedal opening to the total accelerator pedal opening, T max Indicates the total torque obtained by the vehicle when the accelerator pedal opening reaches 100%.

3. The method for controlling torque distribution of a mining four-wheel drive vehicle according to claim 2, characterized in that: The step of obtaining the desired control torque of each moving mechanism driver based on the preset target slip rate and the real-time slip rate includes: After the vehicle starts to move, the real-time slip rates of the four moving mechanisms, namely, the left front wheel, the left rear wheel, the right front wheel and the 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 mobile mechanism power adjustment controller; The mobile mechanism power adjustment controller calculates the desired control torque of each mobile mechanism driver based on PID control.

4. The method for controlling torque distribution of a mining four-wheel drive vehicle according to claim 3, characterized in that: The desired control torque of each moving mechanism driver is expressed as: Where, T fl1_2 、T fr1_2 、T rl1_2 、T rr1_2 They represent the desired control torques of the left front wheel, right front wheel, left rear wheel, and right rear wheel according to the real-time slip rate of the mobile mechanism, respectively. p , k i , k d They represent the proportional coefficient, integral coefficient and differential coefficient of the PID algorithm respectively; S e1 = S0 - S1, S e2 = S0 - S2, S e3 = S0 - S3, S e4 = S0 - S4; where S e1 、S e2 、S e3 、S e4 They 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. S0 represents the target slip rate of the moving mechanism. S1, S2, S3 and S4 represent the real-time slip rates of the left front wheel, right front wheel, left rear wheel and right rear wheel respectively.

5. The method for controlling torque distribution of a mining four-wheel drive vehicle according to claim 4, characterized in that: In the second distribution, the smaller one of the expected 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: T fl2 =min(T fl1_1 ,T fl1_2 ) T fr2 =min(T fr1_1 ,T fr1_2 ) T rl2 =min(T rl1_1 ,T rl1_2 ) T rr2 =min(T rr1_1 ,T rr1_2 ) Where, T fl2 、T fr2 、T rl2 、T rr2 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.

6. A method for controlling torque distribution of a mining four-wheel drive vehicle according to claim 5, characterized in that: The third allocation includes the following steps: Subtract the desired control torque from the driving torque of each moving mechanism driver after the first distribution to obtain a difference between the two; 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.

7. A method for controlling torque distribution of a mining four-wheel drive vehicle according to claim 6, characterized in that: The difference between the driving torque of each mobile mechanism driver and the expected control torque after the first distribution is expressed as: T e1 =T fl1_1 -T fl1_2 T e2 =T fr1_1 -T fr1_2 T e3 =T rl1_1 -T rl1_2 T e4 =T rr1_1 -T rr1_2 Where n is T ei > the number of 0, T e1 、T e2 、T e3 、T e4 They respectively represent the errors between the driving torque of the left front wheel, right front wheel, left rear wheel, and right rear wheel drivers and the expected control torque after the first distribution, and ΔT represents the average value of the four-wheel errors.

8. The method for controlling torque distribution of a mining four-wheel drive vehicle according to claim 7, characterized in that: The result of the third allocation is expressed as: Where T fl3 、T fr3 、T rl3 、T rr3 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 third distribution.

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