Modular distributed electrically-driven heavy-load vehicle climbing method, computing device, storage medium and vehicle

Abstract

The invention relates to a modular distributed electrically-driven heavy-load vehicle climbing method, a computing device, a storage medium and a vehicle, when the gradient is increased to the zero turning angle of the vehicle and has a slope sliding trend, all wheels are controlled to synchronously deflect to the same direction to a climbing angle, and the vehicle is driven to advance in the direction; and when the preset climbing distance is completed or the edge of the ramp is approached, the turning angle of each wheel is reset to zero, and then the wheels are deflected to the climbing angle in the opposite direction to climb. By means of the characteristic that each wheel corner of the modular distributed electric drive heavy-load vehicle is independently driven, the contact point and the contact direction of the wheels and the slope surface are changed when the vehicle climbs an abrupt slope, larger friction force is obtained under the same slope surface area, and the slipping phenomenon possibly caused by the loose slope surface or insufficient friction force is reduced.

Description

Technical Field

[0001] The present invention relates to the control of an electric-driven heavy-load vehicle, and in particular to a modular distributed electric-driven heavy-load vehicle climbing method, a computing device, a storage medium and a vehicle. Background Art

[0002] With the rapid development of new energy vehicles, the electrification of heavy-duty vehicles has gradually become a new research focus. However, because heavy-duty vehicles often face different types of extreme working conditions when performing transportation tasks, especially climbing steep slopes, the transportation efficiency of heavy-duty vehicles is greatly reduced.

[0003] Heavy-duty vehicles have a long wheelbase, a large single-wheel load, and high driving performance requirements. The modular distributed electric drive heavy-duty vehicle adopts an innovative chassis configuration. Compared with the existing chassis structure, the drive shaft is eliminated longitudinally and the steering tie rod is eliminated laterally, which releases more degrees of freedom of movement for the vehicle chassis, allowing the torque and steering angle of each wheel to be independently controlled, making it possible to break through the limit of climbing ability. Summary of the invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a modular distributed electric drive heavy-duty vehicle climbing method, in which the torque and steering angle of each wheel of the vehicle can be independently controlled. When the slope increases to the point where the vehicle has a zero steering angle and there is a tendency to slide down the slope, each wheel is controlled to deflect synchronously in the same direction to the climbing angle, and the vehicle is driven forward in this direction; when the preset climbing distance is completed or the edge of the ramp is approached, the steering angle of each wheel is reset to zero, and then deflected in the opposite direction to the climbing angle to climb the slope. The vehicle body is always kept facing forward, and the characteristics of the independent driving of the steering angles of each wheel of the distributed drive vehicle are utilized to change the contact point and contact direction between the wheel and the slope, obtain greater friction in the same slope area, and reduce the slippage phenomenon that may be caused by soft slopes or insufficient friction.

[0005] Furthermore, the climbing angle is given by the formula Determine, where δ p is the optimal wheel turning angle, F x is the driving force of the vehicle, F z is the normal force of the whole vehicle, and μ is the adhesion coefficient.

[0006] Furthermore, the adhesion coefficient is given by the formula μ = ξλ + p1λ + p2λ 2 , Determine, where ξ is a constant related to the tire material properties, p1 and p2 are tire turning characteristic coefficients, and λ is the optimal slip rate.

[0007] Furthermore, the normal force F z According to formula F z=mgcosα, where g is the acceleration due to gravity and α is the slope angle.

[0008] Furthermore, the driving force F x By formula Determine, where F y It is the cornering force of the whole vehicle.

[0009] The present invention also provides a computing device, including a processor and a memory, wherein the memory stores executable codes, and when the executable codes are executed by the processor, the processor executes the method as described above.

[0010] The present invention also provides a non-transitory machine-readable storage medium having executable codes stored thereon. When the executable codes are executed by a processor of an electronic device, the processor is caused to execute the method as described above.

[0011] The present invention also provides a modular distributed electric drive heavy-duty vehicle, which uses the method as described above.

[0012] Furthermore, the wheel turning angle range is ±35°.

[0013] Furthermore, the vehicle includes six wheels symmetrically arranged on both sides of the vehicle body, and the torque and steering angle of each wheel can be independently controlled.

[0014] The present invention utilizes the characteristic that each wheel angle of a distributed drive vehicle is independently driven, thereby changing the contact point and contact direction between the wheel and the slope when climbing a steep slope, thereby obtaining greater friction under the same slope area and reducing slippage that may be caused by a soft slope or insufficient friction.

[0015] Although the present invention increases the length of the climbing path, it can reduce the instantaneous height that the vehicle climbs, thereby reducing the instantaneous torque demand peak and improving the maximum climbing grade. At the same time, since the direction of the vehicle body is always toward the slope, the risk of rollover is reduced, and driving on uneven slopes has higher stability.

[0016] The present invention realizes maximization of traction during extreme climbing, analyzes the influence of adhesion on traction under slope conditions, balances the longitudinal force and lateral force of the tire, and combines optimal slip rate control to ensure stability while achieving maximization of traction. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0018] Figure 1 Schematic diagram of the climbing method of the present invention;

[0019] Figure 2 is a schematic diagram of longitudinal and transverse force analysis in an embodiment of the present invention;

[0020] Figure 3 is a schematic diagram of normal force analysis in an embodiment of the present invention;

[0021] Figure 4 Schematic diagram of the tire adhesion ellipse in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Embodiment 1:

[0024] See also Figure 1 In the hill climbing method of this embodiment, the torque and steering angle of each wheel of the vehicle can be independently controlled. When the slope increases to the point where the vehicle has a zero steering angle and there is a tendency for the vehicle to slide down the slope, each wheel is controlled to be synchronously deflected in the same direction to a climbing angle, and the vehicle is driven forward in that direction; when the preset climbing distance is completed or the edge of the ramp is approached, the steering angle of each wheel is reset to zero, and then deflected in the opposite direction to the climbing angle to climb the slope.

[0025] The climbing angle in this embodiment is given by the formula Determine, where δ p is the optimal wheel turning angle, F x is the driving force of the vehicle, F z is the normal force of the vehicle, and μ is the adhesion coefficient. In other embodiments, a preset climbing angle may be selected according to the situation. The adhesion coefficient is given by the formula μ=ξλ+p1λ+p2λ 2 , Determine, where ξ is a constant related to the tire material characteristics, p1 and p2 are coefficients related to the tire turning characteristics, and λ is the optimal slip rate. Normal force F z According to formula F z = mgcosα, where g is the acceleration due to gravity and α is the slope angle. Driving force F x By formula Determine, where F y It is the cornering force of the whole vehicle.

[0026] This embodiment is described using a six-wheel test vehicle, and the relevant parameters are shown in the following table:

[0027]

[0028] The climbing process of modular distributed electric drive heavy-duty vehicle is as follows:

[0029] When encountering extreme climbing conditions where straight-line climbing is impossible, the vehicle body is kept facing uphill, and each corner module independently controls the wheels to deflect in the same direction by the same angle. The angle is limited to 0-35°. At this time, the modular distributed electric drive heavy-duty vehicle can break through the climbing limit caused by insufficient power.

[0030] After climbing a certain distance, the lane width limit makes it impossible to climb in a fixed direction for a long time, so the direction needs to be adjusted during the climbing process. After stopping at the lane boundary, the wheels are independently controlled by each corner module to reset, and then deflected in the opposite direction by the same angle, with the angle limit of 0-35°. At this time, the modular distributed electric drive heavy-duty vehicle can continue to perform extreme climbing operations.

[0031] After climbing a slope in the opposite direction for a distance, the lane width limit also makes it impossible to climb in a fixed direction for a long time, and the direction needs to be adjusted during the climbing process. After stopping at the lane boundary, the wheels are independently controlled by each corner module to reset, and then deflected in the opposite direction by the same angle, with the angle limit of 0-35°. At this time, the modular distributed electric drive heavy-duty vehicle can continue to perform extreme climbing operations.

[0032] By repeating the above steps, the climbing function of the modular distributed electric drive heavy-load vehicle can be realized, and the extreme climbing ability of the modular distributed electric drive heavy-load vehicle can be improved.

[0033] In order to better illustrate the improvement of the extreme climbing ability of the modular distributed electric drive configuration over the traditional configuration, a Simulink-Trucksim joint simulation model was built based on the parameters of the test vehicle to verify the proposed extreme climbing method of a modular distributed electric drive heavy-duty vehicle.

[0034] See also Figure 2-Figure 3 , where F flx 、F flx 、F mlx 、F mrx 、F rlx 、F rrx is the driving force of each wheel, F fly 、F fry 、F mly 、F mry 、F rly 、Frry is the cornering force of each wheel, F zf 、F zm 、F zr are the ground normal forces on the front, middle and rear axles, respectively, F xf 、F xm 、F xr The driving forces of the front, middle and rear axles are taken as 0.85, and the driving torque of each wheel is kept at the maximum value of 4200N·m. The maximum slope that the modular distributed electric drive heavy-duty vehicle can maintain on the slope without sliding is solved in the joint simulation platform. Figure 4 The figure shows the tire adhesion ellipse of the modular distributed electric drive heavy-duty vehicle tire during climbing. The figure describes the cornering force and driving force provided by the tire under different working conditions. The horizontal and vertical axes in the figure represent the maximum cornering force and driving force that the tire can provide.

[0035] In traditional configuration, heavy-duty vehicles can usually adjust the front wheel steering angle to increase the vehicle's maximum climbing grade. Similarly, the driving torque of each wheel is kept at the maximum value, and the steering angle is limited to the range of ±35° to adjust the front wheel steering angle. The maximum slope size that the modular distributed electric drive heavy-duty vehicle can maintain on the slope without sliding down is solved in the joint simulation platform.

[0036] The modular distributed electric drive configuration eliminates the drive shaft in the longitudinal direction and the steering tie rod in the transverse direction, releasing more freedom of movement of the vehicle chassis, so that the torque and steering angle of each wheel can be independently controlled. The driving torque of each wheel is kept at the maximum value, and the steering angle of each wheel is adjusted within the steering angle range of ±35°. The front axle + middle axle are rotated, and the rear axle remains stationary; the six wheels are rotated. Joint simulation is performed under two conditions to solve the maximum slope size that the modular distributed electric drive heavy-duty vehicle can maintain on the slope without sliding under different conditions.

[0037] The data obtained from the above tests are shown in the following table:

[0038]

[0039] It can be seen from the above table that under the traditional configuration, by adjusting the front wheel turning angle at 20°, the extreme climbing grade of the heavy-loaded vehicle can only be improved by 1.3%, while at an angle of 35°, an improvement of 1.6% can be obtained. Under the modular distributed electric drive configuration, by adjusting the turning angle of the front axle + middle axle, the extreme climbing grade of the heavy-loaded vehicle can be improved by 7% at an angle of 20°, and by 19.8% at an angle of 35°. By adjusting the turning angle of all wheels, an improvement of 8.1% can be obtained at an angle of 20°, and an improvement of 27.6% can be obtained at an angle of 35°, which greatly improves the extreme climbing grade of the modular distributed electric drive heavy-loaded vehicle. The test results prove that the modular distributed electric drive heavy-loaded vehicle extreme climbing method of the present invention can effectively improve the extreme climbing grade of heavy-loaded vehicles.

[0040] Embodiment 2:

[0041] This embodiment is a computing device, including a processor and a memory, wherein the memory stores codes for executing the method in the above embodiment.

[0042] The processor may be a multi-core processor or may include multiple processors. In some embodiments, the processor may include a general-purpose main processor and one or more special coprocessors, such as a graphics processing unit (GPU), a digital signal processor (DSP), etc. In some embodiments, the processor may be implemented using a customized circuit, such as an application-specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0043] The memory may include various types of storage units, such as system memory, read-only memory (ROM), and permanent storage. Among them, ROM can store static data or instructions required by the processor or other modules of the computer. The permanent storage device may be a readable and writable storage device. The permanent storage device may be a non-volatile storage device that does not lose the stored instructions and data even after the computer is powered off. In some embodiments, the permanent storage device uses a large-capacity storage device (such as a magnetic or optical disk, flash memory) as a permanent storage device. In some other embodiments, the permanent storage device may be a removable storage device (such as a floppy disk, optical drive). The system memory may be a readable and writable storage device or a volatile readable and writable storage device, such as a dynamic random access memory. The system memory may store some or all instructions and data required by the processor at run time. In addition, the memory may include any combination of computer-readable storage media, including various types of semiconductor memory chips (DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), and disks and / or optical disks may also be used. In some embodiments, the memory may include a readable and / or writable removable storage device, such as a laser disc (CD), a read-only digital versatile disc (e.g., DVD-ROM, double-layer DVD-ROM), a read-only Blu-ray disc, an ultra-density optical disc, a flash memory card (e.g., SD card, mini SD card, Micro-SD card, etc.), a magnetic floppy disk, etc. The computer-readable storage medium does not include carrier waves and transient electronic signals transmitted wirelessly or wired.

[0044] The memory stores executable codes thereon, and when the executable codes are executed by the processor, the processor is enabled to execute the above method.

[0045] Embodiment 3:

[0046] This embodiment provides a non-transitory machine-readable memory having executable codes stored thereon. When the executable codes are executed by a processor of an electronic device, the processor is caused to execute the above method.

[0047] A non-temporary machine-readable memory (or computer-readable memory, or machine-readable memory) having executable code (or computer program, or computer instruction code) stored thereon, which, when executed by a processor of an electronic device (or computing device, server, etc.), enables the processor to perform the various steps of the above-mentioned method according to the present invention.

[0048] Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or a combination of both.

[0049] Embodiment 4:

[0050] This embodiment is a modular distributed electric drive heavy-duty vehicle, which uses the method in the above embodiment. The vehicle includes six wheels symmetrically arranged on both sides of the vehicle body. The torque and angle of each wheel can be independently controlled, and the wheel angle range is ±35°.

[0051] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A modular distributed electric drive heavy-load vehicle climbing method, in which the torque and angle of each wheel of the vehicle can be independently controlled, characterized in that: When the slope increases to the point where the vehicle has a tendency to slide down the slope at zero turning angle, the wheels are controlled to deflect synchronously in the same direction to the climbing angle, driving the vehicle forward in that direction; when the preset climbing distance is completed or the edge of the ramp is approached, the turning angles of the wheels are reset to zero, and then deflected in the opposite direction to the climbing angle to climb the slope.

2. The modular distributed electric drive heavy-duty vehicle climbing method according to claim 1, characterized in that: The climbing angle is determined by the following formula: Where δ p is the optimal wheel turning angle, F x is the driving force of the vehicle, F z is the normal force of the whole vehicle, and μ is the adhesion coefficient.

3. The modular distributed electric drive heavy-duty vehicle climbing method according to claim 2 is characterized in that: The adhesion coefficient is determined by the following formula: μ=ξλ+p1λ+p2λ 2 Where ξ is a constant related to tire material properties, p1 and p2 are tire turning characteristic coefficients, and λ is the optimal slip rate.

4. The modular distributed electric drive heavy-duty vehicle climbing method according to claim 3 is characterized in that: Normal force F z Determined by the following formula: F z =mgcosα Where g is the acceleration due to gravity and α is the slope angle.

5. The modular distributed electric drive heavy-duty vehicle climbing method according to claim 4 is characterized in that: Driving force F x Determined by the following formula: Where F y It is the cornering force of the whole vehicle.

6. A computing device, characterized in that: The method comprises a processor and a memory, wherein the memory stores executable codes, and when the executable codes are executed by the processor, the processor executes the method according to any one of claims 1 to 5.

7. A non-transitory machine-readable storage medium, characterized in that: An executable code is stored thereon, and when the executable code is executed by a processor of an electronic device, the processor is caused to execute any method as claimed in claims 1-5.

8. A modular distributed electric drive heavy-duty vehicle, characterized in that: The method comprises using the method described in any one of claims 1 to 5.

9. The modular distributed electric drive heavy-duty vehicle according to claim 8, characterized in that: The wheel turning angle range in the vehicle is ±35°.

10. The modular distributed electric drive heavy-duty vehicle according to claim 8, characterized in that: The vehicle includes six wheels symmetrically arranged on both sides of the vehicle body, and the torque and steering angle of each wheel can be independently controlled.

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