Vehicle differential lock control method, unit, control system and vehicle

Abstract

The present invention provides a vehicle differential lock control method, unit, control system, and vehicle. The vehicle differential lock control method of the present invention, upon receiving a locking command, determines whether the differential lock meets the locking conditions based on a first vehicle state parameter obtained in the current state of the vehicle, and if so, controls the differential lock to be pre-locked; obtains the steering angle in the current state of the vehicle, and if the steering angle is greater than a preset steering angle, controls the differential lock to be locked. The vehicle differential lock control method of the present invention adopts a two-level judgment mode of differential lock pre-locking and differential lock locking, which can better respond to the vehicle state, especially in the locking condition setting after the pre-lock state, the vehicle's escape lock determination is made based on the steering angle in the current state of the vehicle. The response determination to the operation demand is more direct, effectively improving the vehicle's escape capability.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and more particularly to a vehicle differential lock control method. The present invention also relates to a vehicle differential lock control unit used to implement the vehicle differential lock control method, a control system using the control unit, and a vehicle equipped with the control system. Background Art

[0002] The differential lock is installed in the drive axle, which is used to transmit the engine torque from the universal joint to the drive wheels through the main reducer, differential, half-shafts, etc., to reduce the speed and increase the torque; the differential effect of the wheels on both sides is achieved through the differential, ensuring that the inner and outer wheels turn at different speeds.

[0003] An existing electromagnetic differential lock structure, such as the one disclosed, primarily includes a left housing, a right housing, a left and right half-shaft gears, a planetary gear mechanism, a spring, a cam plate, a locking ring, an electromagnetic generator, a mounting bracket, and a push rod. To lock the differential, a button in the cab is activated, direct current flows into the electromagnetic generator, generating magnetic attraction. The cam plate and electromagnetic generator are then locked together, preventing rotation. The cam plate, along with the electromagnetic generator, cannot rotate with the differential housing. When the differential housing rotates, the three push rods rotate together, and the push rods' ball heads contact the cam plate curve. This generates a leftward axial thrust as the spiral cam plate curves upward. After overcoming the resistance of the wave spring, the left half-shaft gear and the differential housing are connected, locking the differential.

[0004] A differential lock with a similar structure as the one above is used in vehicles. When driving on muddy or icy roads with low ground adhesion, one wheel may slip while the other wheel remains stationary, rendering the vehicle unable to move. In this case, the differential lock is activated to rigidly connect the left and right axles, leveraging the friction between the other wheel and the ground to drive the vehicle, thereby driving the wheel with low adhesion to slip, improving the vehicle's ability to escape from difficulties.

[0005] To control the differential lock and improve the vehicle's ability to escape, some existing technologies use electronically controlled differential locks to unlock based on the steering wheel angle or wheel steering angle. Specifically, when the differential lock is locked and the steering wheel or wheel steering angle is greater than a preset angle, the controller unlocks the differential lock. Locking is based on the wheel speed difference and vehicle speed. This control method, when the differential lock is locked, determines whether to activate the lock based on the wheel speed difference and vehicle speed parameters. This method is not optimal for determining the need to escape a vehicle. Summary of the Invention

[0006] In view of this, the present invention aims to propose a vehicle differential lock control method to optimize the locking judgment of the vehicle to escape from distress and improve the vehicle's escape capability.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] A vehicle differential lock control method of the present invention includes:

[0009] When a locking command is received, determining whether a differential lock meets a locking condition based on a first vehicle state parameter obtained from the current state of the vehicle, and if so, controlling the differential lock to pre-lock;

[0010] A steering angle of the vehicle in a current state is obtained, and if the steering angle is greater than a preset steering angle, the differential lock is controlled to be locked.

[0011] Furthermore, if the steering angle is not greater than the preset steering angle, whether the differential lock meets the locking condition is determined based on the second vehicle state parameter obtained under the current state of the vehicle, and if so, the differential lock is controlled to be locked.

[0012] Furthermore, the second vehicle state parameter includes the left and right wheel speeds of the vehicle; if the steering angle is not greater than the preset steering angle, and the speed difference between the left and right wheel speeds of the vehicle is less than a first preset wheel speed difference, the differential lock is controlled to lock.

[0013] Furthermore, the first preset wheel speed difference is 60 rpm.

[0014] Furthermore, if the steering angle is not greater than the preset steering angle and the wheel speed difference between the left and right wheels of the vehicle is not less than the first preset wheel speed difference, control is performed to generate a prompt signal for rejecting locking of the differential lock.

[0015] Furthermore, the prompt signal is a text prompt and / or an audio and visual prompt.

[0016] Furthermore, the second vehicle state parameter includes an accelerator pedal opening of the vehicle; if the steering angle is not greater than the preset steering angle, and the accelerator pedal opening of the vehicle is less than a preset accelerator pedal opening value, the differential lock is controlled to be locked.

[0017] Furthermore, the preset accelerator pedal opening value is 80%.

[0018] Furthermore, the first vehicle state parameter includes a steering assist signal; when a locking command is received and the steering assist is not started, the differential lock is controlled to be pre-locked.

[0019] Furthermore, the first vehicle state parameter includes the left and right wheel speeds and the vehicle speed of the vehicle; when a locking command is received and the vehicle speed is less than a preset speed, and the wheel speed difference is less than a second preset wheel speed difference, the differential lock is controlled to be pre-locked.

[0020] Furthermore, the second preset wheel speed difference is 50 rpm.

[0021] Furthermore, the preset steering angle is 60°.

[0022] The present invention also provides a differential lock control unit, including a processor and a memory, wherein the memory stores a computer-readable code. When the processor executes the computer-readable code, the differential lock control unit executes the vehicle differential lock control method as described above.

[0023] The present invention also provides a vehicle differential lock control system, comprising a differential lock control unit and a detection unit as described above; the detection unit is used to obtain a first vehicle state parameter and a steering angle in the current state of the vehicle; upon receiving a locking command, the differential lock control unit determines whether the differential lock meets the locking conditions based on the first vehicle state parameter in the current state of the vehicle, and if so, controls the differential lock to pre-lock; and based on the differential lock pre-lock state, if the steering angle in the current state of the vehicle is greater than a preset steering angle, controls the differential lock to lock.

[0024] Furthermore, the present invention also provides a vehicle equipped with the vehicle differential lock control system as described above.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] The vehicle differential lock control method described in the present invention adopts a two-level judgment mode of differential lock pre-lock and differential lock locking, which can better respond to the vehicle status, especially in the locking condition setting after the pre-lock state, the escape lock judgment is made according to the steering angle of the vehicle in the current state. Its response to operational requirements is more direct, and the vehicle's escape ability is effectively improved.

[0027] The differential lock control unit, vehicle differential lock control system, and vehicle of the present invention have the same beneficial effects as the above vehicle differential lock control method relative to the prior art, and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 This is a flow chart of the vehicle differential lock control method according to the first embodiment of the present invention;

[0030] Figure 2 This is a flow chart of the pre-locking steps of the vehicle differential lock control method according to the first embodiment of the present invention;

[0031] Figure 3 This is a partial step flow chart of the vehicle differential lock control method according to the second embodiment of the present invention;

[0032] Figure 4 This is a structural block diagram of the differential lock control unit according to the third embodiment of the present invention;

[0033] Figure 5 This is a structural block diagram of a vehicle differential lock control system according to a fourth embodiment of the present invention.

[0034] Description of reference numerals:

[0035] 1. Differential lock control unit; 2. Processor; 3. Memory; 4. Vehicle speed sensor; 5. Left rear wheel speed sensor; 6. Right rear wheel speed sensor; 7. Angle sensor; 8. Accelerator pedal position sensor; 9. Information prompt module. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0037] In the description of this invention, unless otherwise expressly defined, the terms "mounted," "connected," "connect," and "connector" should be interpreted broadly. For example, they can refer to fixed, removable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. The terms "first" and "second" are used for descriptive purposes only and should not be construed to indicate or imply relative importance. Those skilled in the art will understand the specific meanings of these terms in the context of this invention based on specific circumstances.

[0038] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0039] Example 1

[0040] This embodiment relates to a vehicle differential lock control method, such as Figure 1 As shown, the method generally includes two steps:

[0041] Step 1: upon receiving a locking command, determining whether a differential lock meets a locking condition based on a first vehicle state parameter obtained under a current vehicle state, and if so, controlling the differential lock to pre-lock;

[0042] Step 2: Obtain the steering angle of the vehicle in the current state. If the steering angle is greater than a preset steering angle, control the differential lock to lock.

[0043] The vehicle differential lock control method described in the present invention adopts a two-level judgment mode of differential lock pre-locking and differential lock locking, and divides the locking process of the differential lock into two stages. It can better respond to the vehicle status, especially the locking condition setting after the pre-locking state, and makes the escape lock judgment based on the steering angle of the vehicle in the current state. It responds to the operation requirements more directly and effectively improves the vehicle's escape ability.

[0044] The locking process of the differential lock is divided into two stages. Taking the existing electromagnetic differential lock structure as an example, starting the button that controls the differential lock in the cab can send a locking command to the differential lock control unit described below. The differential lock control unit controls the electromagnetic generator to generate magnetic attraction, and the cam plate and the electromagnetic generator fit together and are unable to rotate. This state is the pre-locking state of the differential lock; based on this pre-locking state, if the set vehicle current state parameters meet the locking conditions, the differential lock control unit controls the push rod to cooperate with the cam plate to achieve locking. This state is the locking state.

[0045] Based on the overall description above, in a specific implementation, the first vehicle state parameter in step 1 of this embodiment includes a steering assist signal, left and right wheel speeds, and vehicle speed.

[0046] The steering assist signal indicates whether the vehicle's steering assist function is enabled. This function is used in some vehicles, particularly off-road vehicles, and can be triggered when the off-road cruise assist system is engaged. While maintaining the set speed, this function improves the vehicle's off-road performance, effectively reducing the vehicle's turning radius and thus improving cornering performance. For example, in the steering assist function of the Haval H9 model, after the off-road cruise system is activated, pressing the TAB button on the multimedia display turns the steering assist function on or off. The information center will also display the steering assist function's operating status. This indicates that for vehicles with steering assist, the steering assist function and the differential lock cannot operate simultaneously. Therefore, for such vehicles, the steering assist signal should be tested.

[0047] In addition, the vehicle's left and right wheel speeds serve as pre-locking criteria in this embodiment. Conventional wheel speed sensors can be used to detect the left and right rear wheel speeds. Based on the detected wheel speeds, the difference between the left and right wheel speeds is calculated, representing the wheel speed difference. In this case, a second preset wheel speed difference is set. For example, in this embodiment, the second preset wheel speed difference is set to 50 rpm. The obtained wheel speed difference is then compared with the second preset wheel speed difference, which serves as one of the criteria for determining differential lock pre-locking.

[0048] The vehicle speed signal, another condition for pre-lock determination in this embodiment, actually detects the vehicle's current speed in real time. This real-time speed is compared with a preset speed, and the comparison result serves as another condition for determining differential lock pre-lock. Typically, the preset speed is set, such as 20 km / h in this embodiment.

[0049] The vehicle steering angle obtained in step 2 refers to the vehicle's real-time steering angle after the differential lock pre-lock has been determined and controlled in step 1. This steering angle is based on the steering wheel's initial state when the vehicle's wheels are not rotating, and is the angle the steering wheel has rotated. By comparing the vehicle's real-time steering angle with the preset steering angle, the driver's intention can be better determined, improving the vehicle's ability to escape from distress. Therefore, the preset steering angle, which serves as a threshold, should be set based on the specific vehicle model. For example, in vehicles with larger steering angles, the preset steering angle can be set to 60°, as in this embodiment.

[0050] Based on the above description, the vehicle differential lock control method involved in this embodiment, the specific control method of step 1 is as follows: Figure 2 As shown:

[0051] Step 101, obtaining the steering assist signal, left and right wheel speeds, and vehicle speed in the current state of the vehicle;

[0052] Step 102, receiving a locking command;

[0053] Step 103: Determine whether the steering assist signal is on. If it is on, control the differential lock to reject locking. If it is not on, execute step 104.

[0054] Step 104 , determining whether the vehicle speed is less than a preset speed and whether the wheel speed difference is less than a second preset wheel speed difference; if so, controlling the differential lock to pre-lock and executing step 2 ; otherwise, controlling the differential lock to refuse to lock.

[0055] Example 2

[0056] This embodiment also relates to a vehicle differential lock control method, which further refines step 2 of the first embodiment. The overall concept is based on the specific control when the steering angle is not greater than a preset steering angle in step 2: if the steering angle is not greater than the preset steering angle, a determination is made as to whether the differential lock meets the locking condition based on a second vehicle state parameter obtained from the current vehicle state. If so, the differential lock is locked.

[0057] Traditional differential lock control typically uses a single determination of multiple locking conditions based on vehicle parameters, and then directly locks the differential based on the determination. Therefore, if an unexpected situation occurs during the locking process, such as a sudden high throttle opening with a large difference in left and right wheel speeds, the differential lock push rod can exert a significant impact force on the cam plate, potentially causing it to break and ultimately disable the differential lock. Therefore, in the pre-lock state, if the vehicle's current steering angle is less than a preset steering angle, a secondary determination is made to determine whether the differential lock is locked, implementing locking control. This minimizes damage to the differential lock structure and extends its service life.

[0058] In this embodiment, the second vehicle state parameter mainly includes the left and right wheel speeds of the vehicle and the accelerator pedal opening.

[0059] Among them, the acquisition of the left and right wheel speeds of the vehicle is the same as in Example 1. A first preset wheel speed difference is set corresponding to the left and right wheel speeds. If the steering angle is not greater than the preset steering angle and the wheel speed difference between the left and right wheel speeds of the vehicle is less than the first preset wheel speed difference, the differential lock is controlled to lock; otherwise, the differential lock is controlled to refuse to lock.

[0060] It is worth noting that, in this embodiment, in order to achieve better differential lock locking control, the first preset wheel speed difference is greater than the second preset wheel speed difference. For example, based on Example 1, the first preset wheel speed difference in this embodiment is set to 60 rpm, which can achieve better protection control of the differential lock.

[0061] Furthermore, the term "accelerator pedal opening" should be understood broadly, essentially referring to the throttle valve opening. A preset accelerator pedal opening value is set for this accelerator pedal opening, which can be set to 80%. When the steering angle is not greater than the preset steering angle and the accelerator pedal opening is less than the preset accelerator pedal opening value, the differential lock is engaged. Otherwise, the differential lock is disengaged.

[0062] It is worth noting that this embodiment uses the vehicle's left and right wheel speeds and accelerator pedal position as the second vehicle state parameter. This provides better feedback on the vehicle's current state, thereby providing more favorable locking determination conditions for the differential lock. Of course, in actual implementation, the second vehicle state parameter may alternatively only use the vehicle's left and right wheel speeds or accelerator pedal position.

[0063] Furthermore, to clearly provide feedback to the driver on the differential lock status, when the differential lock is rejected, a prompt signal is generated. This prompt signal can be displayed on the instrument panel in text format, such as "Large left and right wheel speed difference, differential lock rejected, please reduce vehicle speed and try locking," or can be provided by an audible or visual indicator light on the instrument panel.

[0064] Based on the above overall description, Figure 3 Only the specific control steps when the steering angle is not greater than the preset steering angle are shown. Specifically, the following steps are included:

[0065] Step 301, obtaining the left and right wheel speeds and accelerator pedal opening of the vehicle in its current state;

[0066] Step 302: Determine whether the wheel speed difference of the vehicle is less than a first preset wheel speed difference, and whether the accelerator pedal opening is less than a preset accelerator pedal opening; if so, control the differential lock to lock; otherwise, control the differential lock to refuse locking, and execute step 303;

[0067] Step 303 : The control generates and displays a prompt signal for rejecting locking of the differential lock.

[0068] Example 3

[0069] This embodiment relates to a differential lock control unit 1, which comprises Figure 4 As shown, it includes a processor 2 and a memory 3. The memory 3 stores computer-readable code. When the processor 2 executes the computer-readable code, the differential lock control unit 1 executes the vehicle differential lock control method of embodiment 1 or embodiment 2. It is worth noting that the differential lock control unit 1 can be provided independently or in combination with the vehicle's existing differential lock ECU (Electronic Control Unit).

[0070] Example 4

[0071] This embodiment relates to a vehicle differential lock control system, such as Figure 5As shown, it includes the differential lock control unit and detection unit of Example 3. Taking the differential lock control method of Example 2 as an example, in this embodiment, the detection unit is used to obtain a first vehicle state parameter, a steering angle, and a second vehicle state parameter. As shown in the figure, the detection unit includes a vehicle speed sensor 4 for detecting vehicle speed, a left rear wheel speed sensor 5 for detecting the speed of the left rear wheel, a right rear wheel speed sensor 6 for detecting the speed of the right rear wheel, an angle sensor 7 for detecting the steering angle, and an accelerator pedal position sensor 8 for detecting the degree of accelerator pedal opening. Each detection unit transmits the detection signal to the differential lock control unit 1, so that when the differential lock control unit 1 receives the locking command, it determines whether the differential lock meets the locking condition based on the first vehicle state parameter in the current state of the vehicle, and if so, controls the differential lock to be pre-locked; and based on the differential lock pre-lock state, if the steering angle in the current state of the vehicle is greater than the preset steering angle, controls the differential lock to be locked; otherwise, it determines whether the differential lock meets the locking condition based on the second vehicle state parameter in the current state of the vehicle, and if so, controls the differential lock to be locked; otherwise, through the information prompt module 9 connected to the signal output end of the differential lock control unit 1, an information prompt of the differential lock refusing to lock is realized.

[0072] In addition, the present invention also relates to a vehicle equipped with the vehicle differential lock control system of the fourth embodiment.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A vehicle differential lock control method, characterized in that: The method includes: When a locking command is received, determining whether a differential lock meets a locking condition based on a first vehicle state parameter obtained from the current state of the vehicle, and if so, controlling the differential lock to pre-lock; obtaining a steering angle of the vehicle in a current state, and if the steering angle is not greater than a preset steering angle, determining whether the differential lock meets a locking condition based on a second vehicle state parameter obtained in the current state of the vehicle, and if so, controlling the differential lock to lock; Among them, the first vehicle state parameter includes a steering assist signal or the left and right wheel speeds of the vehicle or the vehicle speed; the second vehicle state parameter includes the accelerator pedal opening of the vehicle; if the steering angle is not greater than the preset steering angle and the accelerator pedal opening of the vehicle is less than the preset accelerator pedal opening value, the differential lock is controlled to lock.

2. The vehicle differential lock control method according to claim 1, characterized in that: The second vehicle state parameter includes the left and right wheel speeds of the vehicle; If the steering angle is not greater than the preset steering angle and the wheel speed difference between the left and right wheels of the vehicle is less than a first preset wheel speed difference, the differential lock is controlled to be locked.

3. The vehicle differential lock control method according to claim 2, characterized in that: The first preset wheel speed difference is 60 rpm.

4. The vehicle differential lock control method according to claim 2, characterized in that: If the steering angle is greater than the preset steering angle and the wheel speed difference between the left and right wheels of the vehicle is not less than the first preset wheel speed difference, control generates a prompt signal for rejecting locking of the differential lock.

5. The vehicle differential lock control method according to claim 4, characterized in that: The prompt signal is a text prompt and / or an audio and visual prompt.

6. The vehicle differential lock control method according to claim 1, characterized in that: The preset accelerator pedal opening value is 80%.

7. The vehicle differential lock control method according to claim 1, characterized in that: When the first vehicle state parameter includes a steering assist signal, when a locking command is received and the steering assist is not started, the differential lock is controlled to be pre-locked.

8. The vehicle differential lock control method according to claim 7, characterized in that: When the first vehicle state parameter includes the left and right wheel speeds and the vehicle speed, when a locking command is received and the vehicle speed is less than a preset speed, and the wheel speed difference is less than a second preset wheel speed difference, the differential lock is controlled to be pre-locked.

9. The vehicle differential lock control method according to claim 8, characterized in that: The second preset wheel speed difference is 50 rpm.

10. The vehicle differential lock control method according to claim 1, characterized in that: The preset steering angle is 60°.

11. A differential lock control unit (1), characterized in that: The invention comprises a processor (2) and a memory (3), wherein the memory (3) stores a computer-readable code, and when the processor (2) executes the computer-readable code, the differential lock control unit (1) executes the vehicle differential lock control method according to any one of claims 1 to 10.

12. A vehicle differential lock control system, characterized in that: comprising a differential lock control unit (1) and a detection unit as claimed in claim 11; The detection unit is used to obtain a first vehicle state parameter, a steering angle, and a second vehicle state parameter in a current state of the vehicle; Upon receiving a locking command, the differential lock control unit determines whether the differential lock meets a locking condition based on a first vehicle state parameter in the current state of the vehicle, and if so, controls the differential lock to be pre-locked; and based on the differential lock pre-lock state, if a steering angle in the current state of the vehicle is not greater than a preset steering angle, determines whether the differential lock meets a locking condition based on a second vehicle state parameter obtained in the current state of the vehicle, and if so, controls the differential lock to be locked.

13. A vehicle, characterized in that: The vehicle is provided with the vehicle differential lock control system according to claim 12 .

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