Control method and device for improving driving performance of multi-axle driving vehicle

Abstract

The invention discloses a driving performance improvement control method and device for a multi-axle driving vehicle, and belongs to the technical field of crane driving control, and the control method comprises the following steps: obtaining the vehicle speed, judging whether the vehicle is in a low-speed driving state according to the vehicle speed, and if the vehicle is in the low-speed driving state, controlling to enter an anti-skid mode; starting to obtain a detection signal of the suspension oil cylinder, and judging whether the bearing capacity of the suspension oil cylinder is reduced or not according to the detection signal; if it is judged that the bearing capacity of the suspension oil cylinder is reduced, a vehicle braking system is controlled to apply braking torque to a driving wheel corresponding to the suspension oil cylinder, the road adhesion force is replaced, and therefore the torque of a driving system is not reduced; and if it is judged that the bearing capacity of the suspension oil cylinder is not reduced, the vehicle braking system is controlled to relieve the braking torque of the driving wheel corresponding to the suspension oil cylinder. According to the invention, the risk of abnormal wear of tires and damage of a drive axle caused by application of a differential locking scheme can be avoided while the vehicle is out of trouble.

Description

Technical Field

[0001] This invention relates to a control method and device for improving the driving performance of multi-axle driven vehicles, belonging to the field of crane drive control technology. Background Technology

[0002] All-terrain cranes typically employ a hydropneumatic suspension system. The axle and frame are connected by suspension cylinders. During operation, each suspension cylinder extends or retracts according to changes in the road surface contacted by the wheels, eliminating the impact of uneven road surfaces on the vehicle's center of gravity, keeping the vehicle's posture constant, and ensuring the vehicle's passability and driving comfort.

[0003] All-terrain cranes typically employ multi-axle mechanical drives. When turning or traversing uneven surfaces, differences in rolling distance and angular velocity exist between the various drive wheels. This can cause some wheels to slip while rolling, leading to abnormal tire wear and even damage to the drive axle. Existing technology usually incorporates differentials between the drive wheels to eliminate these damage risks.

[0004] All-terrain cranes, especially heavy-duty ultra-large all-terrain cranes, typically operate at low speeds (e.g., ≤30km / h) on rough, unpaved roads. Due to their long bodies, numerous drive axles, and large transmission chain spans, when road undulations exceed the design range of the hydropneumatic suspension system, the differential will distribute power to the drive wheels with lower resistance. As the wheel slip ratio increases, the vehicle's driving ability may significantly decrease or even lose power. Therefore, a reliable control method is needed to help the vehicle get out of trouble.

[0005] The patent application with publication number CN 114932810 A, entitled "A Technical Solution: Control Method, Device, Medium, and Equipment for Electronic Differential Locks," discloses a design expert mode to assist users in using the differential function. However, the principle of its technical solution is still to achieve vehicle extrication by canceling the differential function. When the differential lock function is used, the differential function between the drive axles is canceled, and the drive axles return to a rigid state. When turning or driving over uneven road surfaces, there are differences in the rolling distance and angular velocity between the drive wheels, resulting in some wheels slipping while rolling. Therefore, vehicles with differential locks require drivers to have strong road condition recognition abilities and driving skills. Improper operation can lead to abnormal tire wear or even damage to the drive axles. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a method and device for improving the driving performance of multi-axle drive vehicles, which can achieve vehicle extrication while avoiding the risk of abnormal tire wear and drive axle damage caused by the application of differential lock scheme.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] In a first aspect, the present invention provides a method for improving the driving performance control of a multi-axle drive vehicle, comprising the following steps:

[0009] The system obtains the vehicle speed and determines whether the vehicle is traveling at a low speed. If the vehicle is traveling at a low speed, the system controls the vehicle to enter anti-skid mode.

[0010] Start acquiring the detection signals of the suspension cylinders, and determine whether the load-bearing capacity of the suspension cylinders has decreased based on the detection signals;

[0011] If it is determined that the load-bearing capacity of the suspension cylinder has decreased, the vehicle braking system is controlled to apply braking torque to the drive wheel corresponding to the suspension cylinder, replacing the road adhesion force, so that the torque of the drive system does not decrease.

[0012] If it is determined that the load-bearing capacity of the suspension cylinder does not decrease, the vehicle braking system is controlled to release the braking torque on the drive wheel corresponding to the suspension cylinder.

[0013] The method of determining whether a vehicle is in a low-speed driving state based on its speed is as follows: when the vehicle speed is less than or equal to 30 km / h, the vehicle is determined to be in a low-speed driving state; otherwise, the vehicle is not in a low-speed driving state.

[0014] When the vehicle is not traveling at low speed, control the exit of anti-skid mode.

[0015] The process of acquiring the detection signal of the suspension cylinder and determining whether the load-bearing capacity of the suspension cylinder has decreased based on the detection signal includes:

[0016] The system detects the extension position of the suspension cylinder. When the suspension cylinder of the drive wheel extends to the preset position, it is determined that the load-bearing capacity of the suspension cylinder has decreased. When the suspension cylinder of the drive wheel retracts to a position not exceeding the preset position, it is determined that the load-bearing capacity of the suspension cylinder has not decreased.

[0017] The preset position is when the suspension cylinder extends to 95% of its maximum extension length.

[0018] The process of acquiring the detection signal of the suspension cylinder and determining whether the load-bearing capacity of the suspension cylinder has decreased based on the detection signal includes:

[0019] The load-bearing capacity of the suspension cylinder is directly detected. When the load-bearing capacity of the suspension cylinder reaches the preset load-bearing capacity value, it is determined that the load-bearing capacity of the suspension cylinder has decreased. When the load-bearing capacity of the suspension cylinder does not reach the preset load-bearing capacity value, it is determined that the load-bearing capacity of the suspension cylinder has not decreased.

[0020] The process of acquiring the detection signal of the suspension cylinder and determining whether the load-bearing capacity of the suspension cylinder has decreased based on the detection signal includes:

[0021] The hydraulic oil pressure of the suspension cylinder is directly detected. When the hydraulic oil pressure of the suspension cylinder reaches the preset hydraulic oil pressure value, it is determined that the load-bearing capacity of the suspension cylinder has decreased. When the load-bearing capacity of the suspension cylinder does not reach the preset hydraulic oil pressure value, it is determined that the load-bearing capacity of the suspension cylinder has not decreased.

[0022] In a second aspect, the present invention provides a control device for improving the driving performance of a multi-axle drive vehicle, comprising:

[0023] The anti-skid control module is used to obtain the vehicle speed and determine whether the vehicle is in a low-speed driving state based on the vehicle speed. If it is in a low-speed driving state, it controls the vehicle to enter the anti-skid mode.

[0024] The load-bearing capacity judgment module is used to start acquiring the detection signal of the suspension cylinder and determine whether the load-bearing capacity of the suspension cylinder has decreased based on the detection signal;

[0025] The braking torque application module is used to control the vehicle braking system to apply braking torque to the drive wheel corresponding to the suspension cylinder if it is determined that the load-bearing capacity of the suspension cylinder has decreased, in order to replace the road adhesion force and ensure that the torque of the drive system does not decrease.

[0026] The braking torque release module is used to control the vehicle braking system to release the braking torque on the drive wheel corresponding to the suspension cylinder if it is determined that the load-bearing capacity of the suspension cylinder has not decreased.

[0027] The beneficial effects of this invention are as follows: This invention provides a method and device for improving the driving performance of multi-axle drive vehicles. It determines whether the load-bearing capacity of the suspension cylinder is reduced based on detection signals, and quickly and accurately determines whether the wheels are in a free-spinning state. It applies braking torque to the drive wheels in a free-spinning state separately, and cancels the braking torque in a non-free-spinning state. Based on the torque distribution principle of the differential, the loss of the overall driving capability of the vehicle is small when using this invention. It can enable the vehicle to fully utilize its driving capability in harsh road conditions, and can help the vehicle get out of trouble while avoiding the risk of abnormal tire wear and drive axle damage caused by applying differential lock schemes. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the operation of an all-terrain crane using an oil-gas suspension system according to the present invention;

[0029] Figure 2 This is a flowchart illustrating the control method for improving the driving performance of a multi-axle driven vehicle according to Embodiment 2 of the present invention.

[0030] Figure 3 This is a flowchart illustrating the control method for improving the driving performance of a multi-axle driven vehicle according to Embodiment 3 of the present invention.

[0031] Figure 4 This is a flowchart illustrating the control method for improving the driving performance of a multi-axle driven vehicle according to Embodiment 4 of the present invention.

[0032] The attached diagram is labeled as follows: 1-Axle; 11-Drive axle 1; 12-Drive axle 2; 13-Drive axle 3; 14-Drive axle 4; 2-Road surface; 3-Suspension cylinder retraction limit position; 4-Suspension cylinder center position; 5-Suspension cylinder extension limit position. Detailed Implementation

[0033] Example 1

[0034] An overview of the chassis, suspension, and drive wheels of an all-terrain crane employing an oil-pneumatic suspension system is as follows: Figure 1 As shown. The axle 1 is connected to the frame using suspension cylinders. Drive axles 11, 12, 13, and 14 are suspension cylinders, capable of vertical extension and retraction. The suspension cylinders are located between the frame and the axle, and each cylinder has a high-strength mechanical interface at both ends, such as a flange or pin hole, to achieve the physical connection between the frame and the axle. One end connects to the frame, and the other end connects to the axle. The suspension cylinders use hydraulic fluid as the power transmission medium.

[0035] Before driving, the suspension cylinders are usually in the middle position of their stroke, corresponding to the middle position 4 of the suspension cylinders in the figure. When driving, the vehicle posture remains unchanged, and each suspension cylinder will extend or retract according to the change of the road surface 2 in contact with the wheel. The maximum retraction corresponds to the suspension cylinder retraction limit position 3 in the figure, and the maximum extension corresponds to the suspension cylinder extension limit position 5 in the figure, eliminating the influence of road surface undulations on the vehicle's center of gravity.

[0036] To eliminate slippage between drive wheels caused by steering and uneven road surfaces, all-terrain cranes are designed with a differential. Its working principle is as follows: Differential speed distribution principle: n1+n2+n3+n4+n5+n6+n7+n8=8n 0， Where: n1 - speed of the left wheel-side half-shaft of axle 1; n2 - speed of the right wheel-side half-shaft of axle 1; n3 - speed of the left wheel-side half-shaft of axle 2; n4 - speed of the right wheel-side half-shaft of axle 2; n5 - speed of the left wheel-side half-shaft of axle 3; n6 - speed of the right wheel-side half-shaft of axle 3; n 7- The speed of the left wheel-side half-shaft of the four-axis; n8 - the speed of the right wheel-side half-shaft of the four-axis; n0 - the input speed of the differential housing.

[0037] As can be seen from the above, when all drive wheels rotate at the same speed, the differential is completely ineffective; when n 1~ When n8 is different, the planetary gears in the differential can rotate at corresponding speeds, so that each drive wheel rotates at a different speed, perfectly adapting to the uneven speed of the wheels when turning or on uneven road surfaces, so that the wheels are always in pure rolling motion relative to the ground.

[0038] The torque distribution principle of a differential: The differential structure is essentially similar to an equal-arm lever, distributing the torque M0 evenly to each drive wheel: M1=M2=M3=M4=M5=M6=M7=M8=M0 / 8, meaning the output torque of the drive wheel determines the input torque. When all drive wheels have the same road adhesion, the differential is completely ineffective; however, when encountering large road imperfections, such as potholes... Figure 1 As shown, when the suspension cylinder 13 is fully extended, it remains suspended in the air. The tire is suspended in the air and loses its adhesion to the ground. The output torque is 0, so the torque of the other wheels is also 0, and the vehicle cannot output power.

[0039] This invention discloses a control method for improving the driving performance of multi-axle driven vehicles, applied to a crane employing a multi-axle drive configuration, a differential mounted on the drive axle, and a hydropneumatic suspension system. Based on the working principle of the hydropneumatic suspension, when the load-bearing capacity of any suspension cylinder decreases, the slip ratio of the corresponding drive wheel increases, potentially leading to wheel spin. Therefore, by using suspension cylinders with detection functions, data can be provided to determine if the tire slip ratio is excessive. By applying braking torque to the drive wheel with the excessive slip ratio, replacing road adhesion, the torque of the drive system does not decrease, thus improving the vehicle's driving performance. The method specifically includes the following steps:

[0040] Step 1: Obtain vehicle speed. Based on the vehicle speed, determine whether the vehicle is traveling at low speed. If it is traveling at low speed, control the vehicle to enter anti-skid mode.

[0041] Step two: Start acquiring the detection signal of the suspension cylinder, and determine whether the load-bearing capacity of the suspension cylinder has decreased based on the detection signal.

[0042] Step 3: If it is determined that the load-bearing capacity of the suspension cylinder has decreased, the vehicle braking system is controlled to apply braking torque to the drive wheel corresponding to the suspension cylinder, replacing the road adhesion force, so that the torque of the drive system does not decrease.

[0043] Step four: If it is determined that the load-bearing capacity of the suspension cylinder does not decrease, then control the vehicle braking system to release the braking torque on the drive wheel corresponding to the suspension cylinder.

[0044] This invention determines whether the suspension cylinder load-bearing capacity has decreased based on detection signals, and quickly and accurately determines whether the wheels are in a free-spinning state: applying braking torque only to the unloaded drive wheels and canceling the braking torque when not unloaded. Based on the torque distribution principle of the differential, the loss of the vehicle's driving capability is minimal when using this invention, allowing the vehicle to fully utilize its driving capability in adverse road conditions. It can help the vehicle get out of trouble while avoiding the risk of abnormal tire wear and drive axle damage caused by applying differential lock schemes.

[0045] Example 2

[0046] This embodiment improves upon Embodiment 1. In step two, the detection signal of the suspension cylinder is acquired. The load-bearing capacity of the suspension cylinder is determined based on the detection signal by detecting whether the suspension cylinder is fully extended. This invention uses a suspension cylinder with position detection function, which can be an integrated sensor, a detection switch, or have an interface for mounting detection sensors or switches. When the vehicle is traveling at low speeds (e.g., ≤30km / h), and the anti-slip mode is selected, when any drive wheel's suspension cylinder extends to a preset position (95% of its maximum extension length), it is considered fully extended. This means the cylinder's load-bearing capacity is reduced, and the vehicle's braking system immediately applies braking torque to the drive wheel corresponding to that cylinder to compensate for the road surface adhesion. The drive system's torque does not decrease. When the corresponding suspension cylinder retracts passively, if it retracts to a position no greater than the preset position, the adhesion between the drive wheel and the ground increases. This is considered incomplete extension, meaning the cylinder's load-bearing capacity does not decrease, and the vehicle's braking system releases the braking torque on the drive wheel corresponding to that cylinder. The specific process is as follows: Figure 2 As shown.

[0047] Example 3

[0048] This embodiment improves upon Embodiment 1. In step two, the detection signal of the suspension cylinder is acquired. The determination of whether the suspension cylinder's load-bearing capacity has decreased is achieved by directly detecting the suspension cylinder's load-bearing capacity. This invention uses a suspension cylinder with a force sensor, which can be an integrated sensor, a detection switch, or have an interface for installing such a sensor or switch. It directly detects the load-bearing capacity of the suspension cylinder. In low-speed driving conditions (e.g., vehicle speed ≤ 30 km / h), when the anti-skid mode is selected, if the load-bearing capacity of any drive wheel's suspension cylinder decreases to a preset load-bearing capacity value, it is determined that the suspension cylinder's load-bearing capacity is low. The vehicle braking system immediately applies braking torque to the drive wheel corresponding to that suspension cylinder to replace the road surface adhesion, and the torque of the drive system does not decrease. When the load-bearing capacity of the suspension cylinder corresponding to that drive wheel increases, i.e., when the suspension cylinder's load-bearing capacity does not reach the preset load-bearing capacity value, the adhesion between the drive wheel and the ground increases, and the suspension cylinder's load-bearing capacity is no longer determined to be low. The vehicle braking system releases the braking torque to the drive wheel corresponding to that suspension cylinder. The specific process is as follows: Figure 3 As shown.

[0049] Example 4

[0050] This embodiment improves upon Embodiment 1. In step two, the detection signal of the suspension cylinder is acquired. The load-bearing capacity of the suspension cylinder is determined based on the detection signal by detecting the hydraulic oil pressure (indirect force measurement). This invention uses a suspension cylinder with hydraulic oil pressure detection. When the vehicle is traveling at low speed (e.g., ≤30km / h), and anti-skid mode is selected, if any drive wheel's suspension cylinder detects that the hydraulic oil pressure has dropped to a preset value, it is determined that the load-bearing capacity of that suspension cylinder is low. The vehicle braking system immediately applies braking torque to the drive wheel corresponding to that suspension cylinder to replace the road adhesion force, and the torque of the drive system does not decrease. When the pressure of the suspension cylinder corresponding to that drive wheel increases, i.e., the load-bearing capacity of the suspension cylinder has not reached the preset hydraulic oil pressure value, the adhesion between the drive wheel and the ground increases, and the load-bearing capacity of that suspension cylinder is no longer determined to be low. The vehicle braking system releases the braking torque to the drive wheel corresponding to that suspension cylinder. The specific process is as follows: Figure 4 As shown.

[0051] Example 5

[0052] This invention discloses a control device for improving the driving performance of a multi-axle drive vehicle, comprising:

[0053] The anti-skid control module is used to obtain the vehicle speed and determine whether the vehicle is in a low-speed driving state based on the vehicle speed. If it is in a low-speed driving state, it controls the vehicle to enter the anti-skid mode.

[0054] The load-bearing capacity judgment module is used to start acquiring the detection signal of the suspension cylinder and determine whether the load-bearing capacity of the suspension cylinder has decreased based on the detection signal;

[0055] The braking torque application module is used to control the vehicle braking system to apply braking torque to the drive wheel corresponding to the suspension cylinder if it is determined that the load-bearing capacity of the suspension cylinder has decreased, in order to replace the road adhesion force and ensure that the torque of the drive system does not decrease.

[0056] The braking torque release module is used to control the vehicle braking system to release the braking torque on the drive wheel corresponding to the suspension cylinder if it is determined that the load-bearing capacity of the suspension cylinder has not decreased.

[0057] The specific functional implementation of each module mentioned above can be found in the relevant content of Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4 or Embodiment 5, and will not be repeated here.

[0058] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A control method for improving the driving performance of a multi-axle drive vehicle, characterized in that: Includes the following steps: The system obtains the vehicle speed and determines whether the vehicle is traveling at a low speed. If the vehicle is traveling at a low speed, the system controls the vehicle to enter anti-skid mode. Start acquiring the detection signals of the suspension cylinders, and determine whether the load-bearing capacity of the suspension cylinders has decreased based on the detection signals; If it is determined that the load-bearing capacity of the suspension cylinder has decreased, the vehicle braking system is controlled to apply braking torque to the drive wheel corresponding to the suspension cylinder, replacing the road adhesion force, so that the torque of the drive system does not decrease. If it is determined that the load-bearing capacity of the suspension cylinder does not decrease, the vehicle braking system is controlled to release the braking torque on the drive wheel corresponding to the suspension cylinder.

2. The method for improving the driving performance of a multi-axle drive vehicle according to claim 1, characterized in that: The method of determining whether a vehicle is in a low-speed driving state based on its speed is as follows: when the vehicle speed is less than or equal to 30 km / h, the vehicle is determined to be in a low-speed driving state; otherwise, the vehicle is not in a low-speed driving state.

3. The method for improving the driving performance of a multi-axle drive vehicle according to claim 1, characterized in that: When the vehicle is not traveling at low speed, control the exit of anti-skid mode.

4. The method for improving the driving performance of a multi-axle drive vehicle according to claim 1, characterized in that: The process of acquiring the detection signal of the suspension cylinder and determining whether the load-bearing capacity of the suspension cylinder has decreased based on the detection signal includes: The system detects the extension position of the suspension cylinder. When the suspension cylinder of the drive wheel extends to the preset position, it is determined that the load-bearing capacity of the suspension cylinder has decreased. When the suspension cylinder of the drive wheel retracts to a position not exceeding the preset position, it is determined that the load-bearing capacity of the suspension cylinder has not decreased.

5. The method for improving the driving performance of a multi-axle drive vehicle according to claim 4, characterized in that: The preset position is when the suspension cylinder extends to 95% of its maximum extension length.

6. The method for improving the driving performance of a multi-axle drive vehicle according to claim 1, characterized in that: The process of acquiring the detection signal of the suspension cylinder and determining whether the load-bearing capacity of the suspension cylinder has decreased based on the detection signal includes: The load-bearing capacity of the suspension cylinder is directly detected. When the load-bearing capacity of the suspension cylinder reaches the preset load-bearing capacity value, it is determined that the load-bearing capacity of the suspension cylinder has decreased. When the load-bearing capacity of the suspension cylinder does not reach the preset load-bearing capacity value, it is determined that the load-bearing capacity of the suspension cylinder has not decreased.

7. The method for improving the driving performance of a multi-axle drive vehicle according to claim 1, characterized in that: The process of acquiring the detection signal of the suspension cylinder and determining whether the load-bearing capacity of the suspension cylinder has decreased based on the detection signal includes: The hydraulic oil pressure of the suspension cylinder is directly detected. When the hydraulic oil pressure of the suspension cylinder reaches the preset hydraulic oil pressure value, it is determined that the load-bearing capacity of the suspension cylinder has decreased. When the load-bearing capacity of the suspension cylinder does not reach the preset hydraulic oil pressure value, it is determined that the load-bearing capacity of the suspension cylinder has not decreased.

8. A control device for improving the driving performance of a multi-axle drive vehicle, characterized in that: include: The anti-skid control module is used to obtain the vehicle speed and determine whether the vehicle is in a low-speed driving state based on the vehicle speed. If it is in a low-speed driving state, it controls the vehicle to enter the anti-skid mode. The load-bearing capacity judgment module is used to start acquiring the detection signal of the suspension cylinder and determine whether the load-bearing capacity of the suspension cylinder has decreased based on the detection signal; The braking torque application module is used to control the vehicle braking system to apply braking torque to the drive wheel corresponding to the suspension cylinder if it is determined that the load-bearing capacity of the suspension cylinder has decreased, in order to replace the road adhesion force and ensure that the torque of the drive system does not decrease. The braking torque release module is used to control the vehicle braking system to release the braking torque on the drive wheel corresponding to the suspension cylinder if it is determined that the load-bearing capacity of the suspension cylinder has not decreased.

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