Traction force control method, traction force control system and articulated dumper

Abstract

The invention belongs to the technical field of engineering machinery, and particularly relates to a traction force control method, a traction force control system and an articulated dump truck. The traction force control method comprises the following steps: judging whether wheels of a drive axle slip or not, if so, further judging which drive axle slips, and judging whether the wheels on one side slip or the wheels on two sides slip, and when judging that one drive axle slips on one side, stopping the traction force control. If yes, an inter-wheel differential lock between the left half shaft and the right half shaft of the slipping drive axle is controlled to be locked; when it is judged that the wheels on the two sides of a certain drive axle slip, the inter-wheel differential lock between the left half axle and the right half axle of the slipping drive axle is controlled to be locked, and meanwhile the inter-axle differential lock between the front drive axle and the middle drive axle and the inter-axle differential lock between the front drive axle and the rear drive axle are controlled to be locked. By means of the traction force control method, the inter-wheel differential lock and / or the inter-axle differential lock can be locked at the accurate time, it is guaranteed that the vehicle can get out of trouble, and no loss is caused to the traction force control system.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering machinery, and in particular to a traction control method, a traction control system and an articulated dump truck. Background Art

[0002] Articulated dump trucks (such as articulated trucks) are earth-moving machines with strong road adaptability in mining and transportation. Its drive system is mainly composed of an engine, a gearbox, a transfer case, three drive axles and an automatic traction control system. Its powerful passing performance enables it to easily adapt to various complex driving conditions. Even so, on slippery and soft roads, articulated dump trucks can still experience wheel slippage and vehicle skidding, or even get stuck. At this time, the driver needs to apply a differential lock under specific conditions to prevent the vehicle from skidding and get the vehicle out of trouble. However, if the driver applies the differential lock at the wrong time, not only will it fail to get out of trouble, but it may also cause transmission system failure, aggravate wheel wear, and excessively increase fuel consumption. Summary of the invention

[0003] The object of the present invention is to provide a traction control method, a traction control system and an articulated dump truck, which can lock the inter-wheel differential lock and / or the inter-axle differential lock at an accurate time, thereby ensuring that the vehicle can escape from trouble without causing damage to the traction control system.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] Traction control methods, including:

[0006] Determine whether the wheels of the drive axle are slipping. If so, further determine which drive axle has the wheel slipping, and determine whether it is unilateral wheel slipping or bilateral wheel slipping. When it is determined that unilateral wheel slipping occurs on a certain drive axle, the inter-wheel differential lock between the left and right half-axles of the drive axle where the slipping occurs is controlled to be locked; when it is determined that bilateral wheel slipping occurs on a certain drive axle, the inter-wheel differential lock between the left and right half-axles of the drive axle where the slipping occurs is controlled to be locked, and at the same time, the inter-axle differential lock between the front drive axle, the middle drive axle and the rear drive axle is controlled to be locked.

[0007] As a preferred technical solution of the traction control method, judging whether the front drive axle wheel is slipping includes:

[0008] Collecting the actual steering angle of the front frame of the vehicle relative to the rear frame;

[0009] It is determined whether the actual steering angle exceeds the steering angle threshold. If so, it is determined that the vehicle is turning. If not, it is determined that the drive axle wheels are slipping.

[0010] As a preferred technical solution of the traction control method, determining which drive axle has wheel slippage, and determining whether the wheel slippage is on one side or on both sides includes:

[0011] Collect the actual speed of the vehicle and the actual speed of the left wheel and the right wheel of each drive axle;

[0012] The theoretical rotation speed of the left and right axles of each drive axle is calculated according to the actual speed of the vehicle, the wheel radius and the wheel-side reduction ratio; at the same time, the actual rotation speed of the left and right axles of each drive axle is calculated according to the actual rotation speed of the left wheel and the actual rotation speed of the right wheel of each drive axle;

[0013] Calculating the slip rate of each left half shaft of each drive axle according to the theoretical speed and the actual speed of the left half shaft of each drive axle, and calculating the slip rate of each right half shaft of each drive axle according to the theoretical speed and the actual speed of the right half shaft of each drive axle;

[0014] Determine whether the slip rate of the left half shaft of each drive axle exceeds the slip rate threshold, and at the same time determine whether the slip rate of the right half shaft of each drive axle exceeds the slip rate threshold. When the slip rate of the left half shaft of a drive axle exceeds the slip rate threshold or the slip rate of the right half shaft exceeds the slip rate threshold, it is determined that the drive axle has unilateral wheel slip; when the slip rate of the left half shaft of a drive axle exceeds the slip rate threshold and the slip rate of the right half shaft also exceeds the slip rate threshold, it is determined that the drive axle has bilateral wheel slip.

[0015] As a preferred technical solution for the traction control method, when the inter-wheel differential lock between the left and right half-axles of the slipping drive axle is locked, the inter-wheel differential lock between the left and right half-axles of the other two non-slipping drive axles is also locked.

[0016] As a preferred technical solution of the traction control method, when the inter-axle differential lock between the front drive axle and the middle drive axle and the rear drive axle is locked, the maximum speed of the engine is simultaneously controlled to be limited within 60% of the rated speed.

[0017] As a preferred technical solution for the traction control method, when the inter-wheel differential lock and / or the inter-axle differential lock are locked, a preset locking time is set at the same time. Only when the inter-wheel differential lock and / or the inter-axle differential lock reaches the preset locking time, the inter-wheel differential lock and / or the inter-axle differential lock are allowed to be unlocked.

[0018] As a preferred technical solution for the traction control method, when the inter-wheel differential lock and / or the inter-axle differential lock reaches a preset locking time, the acceleration in the vehicle's forward direction is detected. When the acceleration exceeds an acceleration threshold, the inter-wheel differential lock and / or the inter-axle differential lock is controlled to be unlocked.

[0019] As a preferred technical solution for the traction control method, the slope of the ground on which the vehicle is running is detected in real time. When the slope exceeds the slope threshold, the inter-wheel differential locks between the left and right half-axles of all drive axles are controlled to be locked, and the inter-axle differential locks between the front drive axle, the middle drive axle and the rear drive axle are controlled to be locked.

[0020] The traction control system adopts the traction control method as described in any of the above schemes.

[0021] An articulated dump truck includes a traction control system as described in the above scheme.

[0022] Beneficial effects of the present invention:

[0023] The present invention provides a traction control method, which can accurately identify the wheel slippage of a drive axle, and can implement different controls according to whether the wheel slippage on one side or on both sides of the drive axle occurs. When it is determined that the wheel slippage on one side occurs on a certain drive axle, the inter-wheel differential lock between the left half-axle and the right half-axle of the drive axle where slippage occurs is controlled to be locked, and the left half-axle and the right half-axle of the drive axle where slippage occurs are locked as a whole, so that the non-slipping wheels can use the adhesion of the road surface to drive the vehicle out of the slipping area, thereby getting the vehicle out of trouble; when it is determined that the wheel slippage on both sides occurs on a certain drive axle, the inter-wheel differential lock between the left half-axle and the right half-axle of the drive axle where slippage occurs is controlled to be locked, and at the same time, the inter-axle differential lock between the front drive axle and the middle drive axle and the rear drive axle is controlled to be locked, and the front drive axle, the middle drive axle and the rear drive axle are locked as a whole. At this time, the torque output by the gearbox is all input to the other two non-slipping drive axles, and the wheels of the other two non-slipping drive axles can drive the vehicle normally, so that the vehicle can pass through the slipping area smoothly. Through the above traction control method, the inter-wheel differential lock and / or the inter-axle differential lock can be locked at the right time, ensuring that the vehicle can escape without causing damage to the traction control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the principle of a traction control system provided by an embodiment of the present invention;

[0025] Figure 2 The process diagram of the traction control method provided by the embodiment of the present invention is as follows Figure 1 ;

[0026] Figure 3 The process diagram of the traction control method provided by the embodiment of the present invention is as follows Figure 2 ;

[0027] Figure 4 The process diagram of the traction control method provided by the embodiment of the present invention is as follows Figure 3 .

[0028] In the figure:

[0029] 10. Engine; 20. Transmission; 30. Transfer case; 40. Front drive axle; 50. Gear transfer mechanism; 60. Middle drive axle; 70. Rear drive axle; 80. Center differential. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0031] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0034] The embodiment of the present invention provides an articulated dump truck (such as an articulated truck) which is an earth-moving machine with strong road adaptability in mining transportation. Figure 1As shown, the articulated dump truck includes a traction control system, including an engine 10, a gearbox 20, a transfer case 30, a front drive axle 40, a gear transfer mechanism 50, a middle drive axle 60 and a rear drive axle 70. The output shaft of the engine 10 is drivingly connected to the input shaft of the gearbox 20, the output shaft of the gearbox 20 is drivingly connected to the input element of the transfer case 30, the transfer case 30 is a planetary gear structure, the planet carrier is the input element of the transfer case 30, the sun gear and the ring gear are the output elements of the transfer case 30, the sun gear is drivingly connected to the front drive axle 40, the ring gear is drivingly connected to the first gear of the gear transfer mechanism 50, and the first gear and the second gear of the gear transfer mechanism 50 are drivingly connected to the middle drive axle 60 and the rear drive axle 70 respectively.

[0035] The central differential 80 of the front drive axle 40 is provided with an inter-wheel differential lock, which controls the locking and separation of the left and right half shafts of the front drive axle 40. The central differential 80 of the middle drive axle 60 is provided with an inter-wheel differential lock, which controls the locking and separation of the left and right half shafts of the middle drive axle 60. The central differential 80 of the rear drive axle 70 is provided with an inter-wheel differential lock, which controls the locking and separation of the left and right half shafts of the rear drive axle 70. The planetary gear of the transfer case 30 is provided with an inter-axle differential lock, which controls the locking and separation of the sun gear and the ring gear, that is, controls the locking and separation of the front drive axle 40, the middle drive axle 60 and the rear drive axle 70.

[0036] like Figures 2 to 4 As shown, an embodiment of the present invention further provides a traction control method based on the traction control system of the articulated dump truck, comprising the following steps:

[0037] S10: Determine whether the wheels of the drive axle are slipping.

[0038] The method to determine whether the drive axle wheels are slipping is:

[0039] S11, collecting an actual steering angle of the front frame of the vehicle relative to the rear frame;

[0040] S12, determine whether the actual steering angle exceeds the steering angle threshold, if so, determine that the vehicle is turning, and end; if not, determine that the drive axle wheel is slipping, and continue to execute step S20.

[0041] S20: Determine which drive axle has wheel slip, and determine whether the wheel slip is on one side or on both sides.

[0042] The drive axle includes a front drive axle 40, a middle drive axle 60 and a rear drive axle 70. It is necessary to determine which of the front drive axle 40, the middle drive axle 60 and the rear drive axle 70 has a wheel slip, and to determine whether it is a single-side wheel slip or a double-side wheel slip. The specific method is as follows:

[0043] S21, collecting the actual vehicle speed V of the entire vehicle and the actual rotation speed n_l of the left wheel and the actual rotation speed n_r of the right wheel of each driving axle.

[0044] S22. Calculate the theoretical rotation speed n_theory of the left and right axles of each drive axle according to the actual vehicle speed V, wheel radius Rd and wheel reduction ratio i_a, where n_theory = V / Rd × i_a. Simultaneously, calculate the actual rotation speed n_ltest of the left and right axles of each drive axle according to the actual rotation speed n_l of the left wheel and the actual rotation speed n_r of the right wheel, where n_ltest = n_l × i_a ​​and n_rtest = n_r × i_a.

[0045] S23. Calculate the slip rate of each left half shaft of each drive axle according to the theoretical speed n_theory and the actual speed n_ltest of the left half shaft of each drive axle, which is (n_theory-n_ltest) / n_theory; calculate the slip rate of each right half shaft of each drive axle according to the theoretical speed n_theory and the actual speed n_rtest of the right half shaft of each drive axle, which is (n_theory-n_rtest) / n_theory.

[0046] S24. Determine whether the slip rate of the left half shaft of each drive axle exceeds the slip rate threshold, and at the same time determine whether the slip rate of the right half shaft of each drive axle exceeds the slip rate threshold; when the slip rate of the left half shaft of a drive axle exceeds the slip rate threshold or the slip rate of the right half shaft exceeds the slip rate threshold, it is determined that the drive axle has unilateral wheel slip; when the slip rate of the left half shaft of a drive axle exceeds the slip rate threshold and the slip rate of the right half shaft also exceeds the slip rate threshold, it is determined that the drive axle has bilateral wheel slip.

[0047] S301. When it is determined that one side of a drive axle has wheel slip, the inter-wheel differential lock between the left half shaft and the right half shaft of the drive axle is controlled to be locked, so that the left half shaft and the right half shaft of the drive axle are locked as one.

[0048] The driving force output of the wheel on the slipping side will be greatly reduced, which will affect the driving force output of the wheel on the other side that is not slipping. By controlling the inter-wheel differential lock between the left and right half shafts of the slipping drive axle, the left and right half shafts of the slipping drive axle are locked together, so that the non-slipping wheel can use the adhesion of the road to drive the vehicle out of the slipping area, thereby getting the vehicle out of trouble.

[0049] S302. When it is determined that the wheels on both sides of a certain drive axle are slipping, the inter-wheel differential lock between the left half shaft and the right half shaft of the drive axle is controlled to be locked, and the left half shaft and the right half shaft of the drive axle are locked as a whole. At the same time, the inter-axle differential lock between the front drive axle 40 and the middle drive axle 60 and the rear drive axle 70 is controlled to be locked, and the front drive axle 40 and the middle drive axle 60 and the rear drive axle 70 are locked as a whole. At the same time, the maximum speed of the engine 10 is controlled to be limited within 60% of the rated speed.

[0050] Since the wheels on both sides slip at the same time and lose adhesion, the inter-wheel differential lock between the left and right half-axles of the drive axle does not work at this time. It is necessary to lock the inter-axle differential lock between the front drive axle 40, the middle drive axle 60 and the rear drive axle 70 at the same time, and lock the front drive axle 40, the middle drive axle 60 and the rear drive axle 70 as a whole. At this time, the torque output by the gearbox 20 is all input to the other two non-slip drive axles, and the wheels of the other two non-slip drive axles can drive the vehicle normally, allowing the vehicle to pass through the slipping area smoothly.

[0051] By controlling the maximum speed of the engine 10 to be limited within 60% of the rated speed, the safety of the other two non-slip drive axles can be ensured.

[0052] As a further solution of step S301 and step S302, when the inter-wheel differential lock between the left and right half-axles of the driving axle that is slipping is locked, the inter-wheel differential locks between the left and right half-axles of the other two driving axles that are not slipping are also locked.

[0053] S40: The inter-wheel differential lock and / or the inter-axle differential lock is locked for a preset locking time.

[0054] A preset locking time is set, and only after the preset locking time has passed, the controller is allowed to unlock the inter-wheel differential lock between the left and right half shafts of the drive axle and / or the inter-axle differential lock between the front drive axle 40, the middle drive axle 60 and the rear drive axle 70. This is to prevent the controller from frequently locking and releasing the inter-wheel differential lock and the inter-axle differential lock when the vehicle is driving on alternating conditions of slipping and non-slipping roads, thereby affecting the reliability of the inter-wheel differential lock and the inter-axle differential lock.

[0055] S50: Detect the acceleration of the vehicle in the forward direction, and when the acceleration exceeds an acceleration threshold, control the inter-wheel differential lock and / or the inter-axle differential lock to be unlocked.

[0056] When the acceleration exceeds the acceleration threshold, it means that the vehicle has passed the slipping area, and the inter-wheel differential locks between the left and right half shafts of all drive axles and / or the inter-axle differential locks between the front drive axle 40 and the middle drive axle 60 and the rear drive axle 70 can be unlocked.

[0057] During the execution of the above S10-S50, the slope of the ground on which the vehicle is running is detected in real time. When the slope exceeds the slope threshold, the inter-wheel differential locks between the left and right half shafts of all drive axles are controlled to be locked, and the inter-axle differential locks between the front drive axle 40, the middle drive axle 60 and the rear drive axle 70 are controlled to be locked. The adhesion of the whole vehicle is transmitted to all wheels more evenly, so as to improve the driving safety of the whole vehicle.

[0058] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A traction control method, characterized in that: include: Determine whether the wheels of the drive axle are slipping. If so, further determine which drive axle has the wheel slipping, and determine whether it is unilateral wheel slipping or bilateral wheel slipping. When it is determined that unilateral wheel slipping occurs on a certain drive axle, the inter-wheel differential lock between the left and right half-axles of the drive axle where the slipping occurs is controlled to be locked; when it is determined that bilateral wheel slipping occurs on a certain drive axle, the inter-wheel differential lock between the left and right half-axles of the drive axle where the slipping occurs is controlled to be locked, and at the same time, the inter-axle differential lock between the front drive axle, the middle drive axle and the rear drive axle is controlled to be locked.

2. The traction control method according to claim 1, characterized in that: Judging whether the front drive axle wheels are slipping includes: Collecting the actual steering angle of the front frame of the vehicle relative to the rear frame; It is determined whether the actual steering angle exceeds the steering angle threshold. If so, it is determined that the vehicle is turning. If not, it is determined that the drive axle wheels are slipping.

3. The traction control method according to claim 1, characterized in that: Determining which drive axle has wheel slippage, and determining whether it is single-side wheel slippage or double-side wheel slippage includes: Collect the actual speed of the vehicle and the actual speed of the left wheel and the right wheel of each drive axle; The theoretical rotation speed of the left and right axles of each drive axle is calculated according to the actual speed of the vehicle, the wheel radius and the wheel-side reduction ratio; at the same time, the actual rotation speed of the left and right axles of each drive axle is calculated according to the actual rotation speed of the left wheel and the actual rotation speed of the right wheel of each drive axle; Calculating the slip rate of each left half shaft of each drive axle according to the theoretical speed and the actual speed of the left half shaft of each drive axle, and calculating the slip rate of each right half shaft of each drive axle according to the theoretical speed and the actual speed of the right half shaft of each drive axle; Determine whether the slip rate of the left half shaft of each drive axle exceeds the slip rate threshold, and at the same time determine whether the slip rate of the right half shaft of each drive axle exceeds the slip rate threshold. When the slip rate of the left half shaft of a drive axle exceeds the slip rate threshold or the slip rate of the right half shaft exceeds the slip rate threshold, it is determined that the drive axle has unilateral wheel slip; when the slip rate of the left half shaft of a drive axle exceeds the slip rate threshold and the slip rate of the right half shaft also exceeds the slip rate threshold, it is determined that the drive axle has bilateral wheel slip.

4. The traction control method according to claim 1, characterized in that: When the inter-wheel differential lock between the left and right half-axles of the driving axle that is slipping is locked, the inter-wheel differential locks between the left and right half-axles of the other two driving axles that are not slipping are also locked.

5. The traction control method according to claim 1, characterized in that: When the inter-axle differential lock between the front drive axle, the middle drive axle and the rear drive axle is locked, the maximum speed of the engine is controlled to be limited within 60% of the rated speed.

6. The traction control method according to claim 1, characterized in that: When the inter-wheel differential lock and / or the inter-axle differential lock are locked, a preset locking time is set at the same time. When the inter-wheel differential lock and / or the inter-axle differential lock reaches the preset locking time, the inter-wheel differential lock and / or the inter-axle differential lock are allowed to be unlocked.

7. The traction control method according to claim 6, characterized in that: When the inter-wheel differential lock and / or the inter-axle differential lock reaches a preset locking time, the acceleration in the vehicle's forward direction is detected, and when the acceleration exceeds an acceleration threshold, the inter-wheel differential lock and / or the inter-axle differential lock is controlled to be unlocked.

8. The traction control method according to any one of claims 1 to 7, characterized in that: The slope of the ground on which the vehicle is running is detected in real time. When the slope exceeds the slope threshold, the inter-wheel differential locks between the left and right half-axles of all drive axles are controlled to be locked, and the inter-axle differential locks between the front drive axle, the middle drive axle and the rear drive axle are controlled to be locked.

9. A traction control system, characterized in that: A traction control method as described in any one of claims 1 to 8 is adopted.

10. An articulated dump truck, characterized in that: Includes the traction control system as claimed in claim 9.

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