A control method and control device for steering chassis of new energy vehicles

Abstract

This invention provides a control method and control device for a steering chassis of a new energy vehicle. The control method includes: S1, acquiring the current forward speed of the vehicle, the steering requirement angle, and the actual rotation angle sensed by an angle sensor component, wherein the actual rotation angle is the angle of rotation of the front frame and the rear frame around a rotation point; S2, determining the speed difference between the drive wheels in the current driving mode based on the vehicle's current driving mode, pre-configured vehicle steering parameters, and the vehicle speed and steering requirement angle obtained in S1, or determining the speed difference between the drive wheels in the current driving mode based on the steering requirement angle; S3, controlling the rotational speed of the drive motor in the current driving mode according to the speed difference determined in S2 and the actual rotation angle obtained in S1. This invention can reduce the complexity of the steering chassis, save energy consumption during steering, and improve the vehicle's steering response speed and steering angle.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, particularly to the field of agricultural vehicles, and specifically to a control method and control device for the steering chassis of new energy vehicles. Background Technology

[0002] With the increasing scarcity of oil resources and worsening environmental pollution, the requirements for energy conservation and environmental protection in vehicles are becoming increasingly stringent in order to achieve sustainable development for humankind. Electrification can not only solve the problems of energy conservation and emission reduction, but also drive technological leaps, making it an inevitable trend in social development.

[0003] In new energy vehicles, articulated steering offers flexible steering, strong off-road capability, and the ability to operate in harsh environments. In agricultural vehicles, it is particularly well-suited for scenarios involving the transport of agricultural equipment. Currently, articulated steering vehicles commonly use hydraulic steering systems, which control the extension and retraction of hydraulic cylinders on both sides of the front and rear vehicle hinge points to achieve steering movements. However, articulated steering systems using hydraulic transmission mechanisms suffer from slow response, poor stability, and high fuel consumption. Furthermore, traditional articulated steering vehicles experience significant tire wear. Moreover, steering schemes that alter the articulation angles between the front and rear axles and the chassis have considerable limitations in achieving small-angle steering.

[0004] In summary, the strategy of steering based on hydraulic cylinders on both sides of the vehicle's hinge point suffers from structural complexity and slow speed response. Therefore, reducing steering energy consumption and improving steering efficiency are urgently needed. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a control method and control device for the steering chassis of new energy vehicles, which mainly solves the problem of low steering efficiency in new energy vehicles.

[0006] The objective of this invention is achieved through the following methods:

[0007] According to a first aspect of the present invention, a control method for a steering chassis of a new energy vehicle is provided. The steering chassis includes: a front frame, a rear frame, a front axle assembly, and a rear axle assembly, wherein the front frame is connected to the front axle assembly, the rear frame is connected to the rear axle assembly, and drive motors are respectively provided at both ends of the front axle assembly and the rear axle assembly. The drive motors are used to drive wheels to rotate in a fixed direction. The steering chassis further includes an angle sensor assembly. The front frame and the rear frame are rotatably connected, and the angle sensor assembly is used to detect the horizontal rotation angle between the front frame and the rear frame. The control method includes:

[0008] S1. Obtain the current vehicle's forward speed, steering requirement angle, and actual rotation angle sensed by the angle sensor component. The actual rotation angle is the angle at which the front frame and the rear frame rotate around the rotation point in the forward direction. S2. Determine the speed difference between the drive wheels in this driving mode based on the vehicle's current driving mode, pre-configured vehicle steering parameters, and the vehicle speed and steering requirement angle obtained in S1. Alternatively, determine the speed difference between the drive wheels in this driving mode based on the steering requirement angle. S3. Control the rotational speed of the drive motor in the driving mode according to the speed difference determined in S2 and the actual rotation angle obtained in S1.

[0009] In some embodiments of the present invention, the driving mode includes a front-drive mode; S2 includes: S21', determining the speed difference between the left front wheel and the right front wheel in the front-drive mode according to the steering demand angle.

[0010] In some embodiments of the present invention, in the front-drive mode, S3 includes:

[0011] S31': Based on the speed difference determined in S21' and the actual rotation angle obtained in S1, control the speed of the drive motor in front-drive mode; wherein, simultaneously control the left front-wheel drive motor to increase the speed corresponding to the speed difference based on the front frame's speed, and control the right front-wheel drive motor to decrease the speed corresponding to the speed difference based on the front frame's speed; or simultaneously control the left front-wheel drive motor to decrease the speed corresponding to the speed difference based on the front frame's speed, and control the right front-wheel drive motor to increase the speed corresponding to the speed difference based on the front frame's speed.

[0012] In some embodiments of the present invention, in S21', the speed difference between the left front wheel and the right front wheel in front-drive mode is determined by the following rule:

[0013] The driving speed difference is determined based on the obtained steering demand angle and using a pre-configured conversion table between the steering demand angle and the driving speed difference.

[0014] In some embodiments of the present invention, in S31', the rotational speed corresponding to the speed difference is obtained by the following rule:

[0015] Φ1= V delta1 / D1

[0016] Where Φ1 represents the rotational speed corresponding to the speed difference, V delta1 D1 represents the speed difference, and D1 represents the track width between the left and right front wheels. This indicates the rate of change of the front wheel motor's rotational speed.

[0017] In some embodiments of the present invention, the driving mode includes a four-wheel drive mode; S2 includes:

[0018] S21'': Based on the pre-configured vehicle steering parameters and the vehicle speed and steering requirement angle obtained in S1, determine the speed difference between the front wheels and the rear wheels in four-wheel drive mode, wherein the vehicle speed obtained in S1 is used as the speed of the front frame; determine the speed difference between the front wheels in four-wheel drive mode based on the steering requirement angle; calculate the speed difference between the rear wheels and the speed of the rear frame based on the speed of the front frame, the steering requirement angle, and the pre-configured vehicle steering parameters.

[0019] In some embodiments of the present invention, in four-wheel drive mode, S3 includes:

[0020] S31'': Based on the speed difference of the front frame determined in S21'' and the actual rotation angle obtained in S1, control the speed of the drive motor in front-drive mode; wherein, simultaneously control the left front-wheel drive motor to increase the speed corresponding to the speed difference of the front frame based on the current driving speed, the right front-wheel drive motor to decrease the speed corresponding to the speed difference of the front frame based on the current driving speed, the left rear-wheel drive motor to decrease the speed corresponding to the speed difference of the rear frame based on the driving speed of the rear frame, and the right rear-wheel drive motor to increase the speed corresponding to the speed difference of the rear frame based on the driving speed of the rear frame, or simultaneously control the left front-wheel drive motor to decrease the speed corresponding to the speed difference of the front frame based on the current driving speed, the right front-wheel drive motor to increase the speed corresponding to the speed difference of the front frame based on the current driving speed, the left rear-wheel drive motor to increase the speed corresponding to the speed difference of the rear frame based on the current driving speed, and the right rear-wheel drive motor to decrease the speed corresponding to the speed difference of the rear frame based on the current driving speed.

[0021] In some embodiments of the present invention, in S21'', the speed difference between the front wheels and between the rear wheels and the speed of the rear frame in four-wheel drive mode are determined by the following rules:

[0022] L2×(V delta2 / D2)=V1×sin(θ)-L1×(V dalta1 / D1)×cos(θ)

[0023] V2 = V1 × cos(θ) + L1 × (V delta1 / D1)×sin(θ)

[0024] Where L2 represents the distance between the rear axle and the rotation point, the rotation point being the point of rotation between the front frame and the rear frame, V delta2D1 represents the speed difference between the rear wheels, D2 represents the wheelbase between the left and right rear wheels, V1 represents the speed of the front frame, V2 represents the speed of the rear frame, θ represents the steering angle required, D1 represents the wheelbase between the left and right front wheels, and L1 represents the distance from the front axle to the point of rotation.

[0025] In some embodiments of the present invention, in step S31'', the rotational speed corresponding to the speed difference of the rear frame is obtained by the following rule:

[0026] Φ2= V delta2 / D2

[0027] Where Φ2 represents the rotational speed corresponding to the speed difference of the rear frame, V delta2 V represents delta2 D2 represents the speed difference between the rear wheels, and D2 represents the track width between the left and right rear wheels. This indicates the rate of change of the speed of the rear wheel motor drive.

[0028] According to a first aspect of the present invention, a control device for a steering chassis of a new energy vehicle is provided, the control device comprising a controller that executes the control method provided in the first aspect of the present invention.

[0029] Compared with the prior art, the present invention has the following beneficial effects: by eliminating the extension and retraction of the hydraulic cylinders on the left and right sides of the hinge points of the front and rear frames, the present invention can reduce the complexity of the steering chassis and save energy consumption during steering; furthermore, by controlling the vehicle's steering by directly acting on the speed difference between the drive wheels through the steering demand angle (preferably through the horizontal rotation angle between the front and rear frames), the vehicle's steering response speed and steering angle can be improved. Attached Figure Description

[0030] The embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0031] Figure 1 This invention provides a schematic diagram of the structure of a steering chassis for a new energy vehicle.

[0032] Figure 2 This invention provides a schematic flowchart of a control method for a steering chassis of a new energy vehicle.

[0033] Figure 3 A simplified structural diagram of a steering chassis for a new energy vehicle is provided as an embodiment of the present invention;

[0034] Figure 4 This invention provides a speed decomposition diagram of a steering chassis for a new energy vehicle.

[0035] Explanation of reference numerals in the attached drawings: 1. Rear frame; 2. Front frame; 3. Rotation point between the rear frame and the front frame; 4. Front axle assembly; 5. Rear axle assembly; 6. Wheel; 7. Drive motor; 8. Angle sensor assembly. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the invention.

[0037] As mentioned in the background art, "the strategy of steering based on hydraulic cylinders on both sides of the vehicle body hinge point has the problems of complex structure and slow speed response." To solve these problems, this invention reduces the complexity of the vehicle steering structure by adjusting the structure of the vehicle chassis and reducing hydraulically driven steering structures such as hydraulic push rods. On this basis, in order to obtain a better steering radius and response efficiency, the steering angle utilizes vehicle steering parameters such as the horizontal rotation point between the front and rear frames, which directly act on the speed difference between the drive wheels to control the vehicle steering, thereby improving the vehicle steering flexibility and efficiency.

[0038] To better illustrate the implementation process of this invention, we will first introduce a new energy vehicle steering chassis provided by this invention. For example... Figure 1 As shown, the steering chassis includes: a front frame 2, a rear frame 1, a front axle assembly 4, and a rear axle assembly 5. The front frame 2 is connected to the front axle assembly 4, and the rear frame 1 is connected to the rear axle assembly 5. Drive motors 7 are respectively provided at both ends of the front axle assembly 4 and the rear axle assembly 5. The drive motors 7 are used to drive the wheels 6 to rotate in a fixed direction. The steering chassis also includes an angle sensor assembly 8. The front frame and the rear frame are rotatably connected, and the angle sensor assembly is used to detect the horizontal rotation angle between the front frame and the rear frame.

[0039] It should be noted that in this embodiment, the drive motor 7 is used to drive the wheel 6 to rotate in a fixed direction, and preferably the wheel is connected to the front axle assembly in a way that prevents rotation; the drive motor 7 can be connected to the wheel through a reducer. In this embodiment, the front frame 2 and the rear frame 1 are steered through the rotation point 3 between the rear frame and the front frame. The rotation point 3 can be connected by means of hinges or other methods. The hardware units such as batteries required during vehicle use are selected based on the understanding of new energy vehicles by those skilled in the art, and will not be elaborated here.

[0040] To address vehicle steering efficiency, based on the aforementioned vehicle chassis, according to an embodiment of the present invention, a control method for the steering chassis of new energy vehicles is provided. For example... Figure 2As shown, the control method includes: S1, acquiring the current vehicle's forward speed, steering requirement angle, and actual rotation angle sensed by the angle sensor component, wherein the actual rotation angle is the angle of rotation of the front frame and the rear frame around the rotation point in the forward direction; S2, determining the speed difference between the drive wheels in the current driving mode based on the vehicle's current driving mode, pre-configured vehicle steering parameters, and the vehicle speed and steering requirement angle obtained in S1, or determining the speed difference between the drive wheels in the current driving mode based on the steering requirement angle; S3, controlling the speed of the drive motor in the driving mode according to the speed difference determined in S2 and the actual rotation angle obtained in S1.

[0041] It should be noted that the pre-configured vehicle steering parameters include the distance between the rear axle and the rotation point, the track width between the left and right rear wheels, the track width between the left and right front wheels, and the distance between the front axle and the rotation point. Understanding these pre-configured vehicle steering parameters is an adaptive interpretation of the parameters used in the fundamental control method. The use of these parameters will be further explained below. In this embodiment, parameters such as the steering angle are directly applied to the speed difference between the drive wheels. This can significantly improve steering efficiency and agility by utilizing the rotation point 3 between the rear and front frames to expand the steering angle. The speed difference between the drive wheels in drive mode can well adapt to the user's steering efficiency experience. For example, in front-wheel drive or rear-wheel drive mode, steering is faster and more comfortable; in four-wheel drive mode, steering response is faster and more agile. The control method provided by this invention will be explained in detail below.

[0042] In step S1 of the control method provided by this invention, the current vehicle's forward speed, steering requirement angle, and actual rotation angle sensed by the angle sensor assembly are acquired. The current vehicle's forward speed (which can be understood as the forward portion in the vehicle's forward direction, such as the speed of the front frame) can be directly acquired by units such as the vehicle's controller; the steering requirement angle is generated based on the vehicle's steering wheel and its associated structures; and the angle sensor assembly can sense the actual rotation angle. It should be noted that the parameter acquisition process in this embodiment is known to those skilled in the art and will not be described in detail here.

[0043] The speed control process in the preferred drive modes of the present invention, namely front drive mode and four drive mode, will be explained in this embodiment.

[0044] In front-drive mode, according to an embodiment of the present invention, control method S2 includes: S21', determining the speed difference between the left and right front wheels in front-drive mode based on the steering demand angle. Preferably, the speed difference is determined based on the obtained steering demand angle and using a pre-configured conversion table between the steering demand angle and the speed difference. The steering demand angle and the speed difference are a relationship table derived from multiple statistical experiments; using this table can improve the comfort of steering control. Further, the engine speed corresponding to the speed difference is obtained through the following rules:

[0045] Φ1= V delta1 / D1

[0046] Where Φ1 represents the rotational speed corresponding to the speed difference, V delta1 D1 represents the speed difference, and D1 represents the track width between the left and right front wheels. This indicates the rate of change of the front wheel motor's rotational speed.

[0047] It should be noted that when controlling vehicle steering using speed differences, the target steering angle (required steering angle) can be quickly determined based on the speed difference. During wheel speed control, the speed change ratio of each drive motor operates according to a set ratio. To simplify the control process, the speed change along the same axis is set as... It can quickly establish the increase or decrease of the rotational speed of the drive wheels.

[0048] In front-drive mode, control method S3 includes: S31', controlling the speed of the drive motor in front-drive mode based on the speed difference determined in S21' and the actual rotation angle obtained in S1; wherein, simultaneously controlling the left front wheel drive motor to increase its speed corresponding to the speed difference based on the front frame's speed, and the right front wheel drive motor to decrease its speed corresponding to the speed difference based on the front frame's speed; or simultaneously controlling the left front wheel drive motor to decrease its speed corresponding to the speed difference based on the front frame's speed, and the right front wheel drive motor to increase its speed corresponding to the speed difference based on the front frame's speed. It should be noted that when... The parameters of the drive motors are preferably the same, which can improve control precision while reducing control difficulty. The increase or decrease of the speed of the left front wheel drive motor is determined according to the required steering angle. For example, when the vehicle turns left, the speed of the left front wheel drive motor decreases and the speed of the right front wheel drive motor increases. The decrease and increase in speed are each half of the difference in driving speed, which can reduce control difficulty and improve steering comfort.

[0049] In four-wheel drive mode, both the front and rear wheels can be used as drive wheels, further reducing vehicle steering delay time. In four-wheel drive mode, control method S2 includes: S21'', determining the speed difference between the front wheels and the rear wheels in four-wheel drive mode based on pre-configured vehicle steering parameters and the vehicle speed and steering requirement angle obtained in S1, wherein the vehicle speed obtained in S1 is used as the speed of the front frame; determining the speed difference between the front wheels in four-wheel drive mode based on the steering requirement angle; calculating the speed difference between the rear wheels and the speed of the rear frame based on the speed of the front frame, the steering requirement angle, and the pre-configured vehicle steering parameters.

[0050] Accordingly, S3 in the control method includes: S31'', controlling the speed of the drive motor in front-drive mode based on the speed difference of the front frame determined in S21'' and the actual rotation angle obtained in S1; wherein, simultaneously controlling the left front-wheel drive motor to increase the speed corresponding to the speed difference of the front frame based on the current driving speed, the right front-wheel drive motor to decrease the speed corresponding to the speed difference of the front frame based on the current driving speed, the left rear-wheel drive motor to decrease the speed corresponding to the speed difference of the rear frame based on the driving speed of the rear frame, and the right rear-wheel drive motor to increase the speed corresponding to the speed difference of the rear frame based on the driving speed of the rear frame, or simultaneously controlling the left front-wheel drive motor to decrease the speed corresponding to the speed difference of the front frame based on the current driving speed, the right front-wheel drive motor to increase the speed corresponding to the speed difference of the front frame based on the current driving speed, the left rear-wheel drive motor to increase the speed corresponding to the speed difference of the rear frame based on the current driving speed, and the right rear-wheel drive motor to decrease the speed corresponding to the speed difference of the rear frame based on the current driving speed.

[0051] Furthermore, in S21'', the speed difference between the front wheels and the rear wheels, as well as the speed of the rear frame, in four-wheel drive mode are determined by the following rules:

[0052] L2×(V delta2 / D2)=V1×sin(θ)-L1×(V dalta1 / D1)×cos(θ)

[0053] V2 = V1 × cos(θ) + L1 × (V delta1 / D1)×sin(θ)

[0054] Where L2 represents the distance between the rear axle and the rotation point, the rotation point being the point of rotation between the front frame and the rear frame, V delta2D1 represents the speed difference between the rear wheels, D2 represents the wheelbase between the left and right rear wheels, V1 represents the speed of the front frame, V2 represents the speed of the rear frame, θ represents the steering angle required, D1 represents the wheelbase between the left and right front wheels, and L1 represents the distance from the front axle to the point of rotation.

[0055] In S31'', the rotational speed corresponding to half the speed difference of the rear frame is obtained by the following rule:

[0056] Φ2= V delta2 / D2

[0057] Where Φ2 represents the rotational speed corresponding to the speed difference of the rear frame, V delta2 V represents delta2 D2 represents the speed difference between the rear wheels, and D2 represents the track width between the left and right rear wheels. This indicates the rate of change of the speed of the rear wheel motor drive.

[0058] It should be noted that once the speed difference between the rear wheels on the rear frame is determined, the corresponding rates of speed change between the rear and front wheels can be allocated according to a set ratio to achieve a balance between steering comfort and efficiency. Preferably, S is set to 0.5, and K of the front vehicle is set to 0.5.

[0059] To better illustrate the interrelationships between velocities in this invention, a velocity model will be used for further explanation below.

[0060] like Figure 3 As shown, the vehicle chassis is represented by a concise mathematical model. D represents the track width, preferably the track width D1 between the left and right front wheels is the same as the track width D2 between the left and right rear wheels; the hinge point (sometimes called the rotation point) is abstracted as point Ob, the front axle is abstracted as Oc, and the rear axle is abstracted as Oa. L1 represents the distance between the front axle and the rotation point, and L2 represents the distance between the rear axle and the rotation point.

[0061] Taking four-wheel drive mode as an example, speed decomposition is performed at the articulation point Ob. For example... Figure 4 As shown,

[0062] The front frame has a velocity perpendicular to the direction of travel, V3 = L1 × Φ1 = L1 × (Vdelta1 / D);

[0063] The velocity of the rear frame perpendicular to the rear frame direction is V4 = V1 × sin(θ) - V3 × cos(θ).

[0064] The velocity of the rear frame is V2 = V1 × cos(θ) + V3 × sin(θ).

[0065] For the latter half, V4 = L2 × Φ2 = L2 × (Vdelta2 / D)

[0066] Among them, V delta2 V represents delta2 L1 represents the speed difference between the rear wheels; L2 represents the distance from the rear axle to the point of rotation, which is the point of rotation between the front frame and the rear frame; V represents the distance between the rear wheel axle and the point of rotation. delta2 D1 represents the speed difference between the rear wheels, D2 represents the wheelbase between the left and right rear wheels, V1 represents the speed of the front frame, V2 represents the speed of the rear frame, θ represents the steering angle required, D1 represents the wheelbase between the left and right front wheels, and L1 represents the distance between the front axle and the point of rotation. This indicates the rate of change of the rear wheel motor drive speed. This indicates the rate of change of the front wheel motor's rotational speed.

[0067] The differential relationship of the front frame is then:

[0068] L2×(V delta2 / D)=V1×sin(θ)L1×(V dalta1 / D)×cos(θ).......................(1)

[0069] The speed relationship between the front and rear frames is as follows:

[0070] V2=V1×cos(θ)+L1×(Vdelta1 / D)×sin(θ).............(2)

[0071] Among the unknowns mentioned above, V delta1 V1 is determined by the steering wheel angle, and V2 is determined by the throttle opening; therefore, V can be calculated. delta2 And V2.

[0072] In the control method, the speed of the drive motor in the driving mode is controlled based on the speed difference determined in S2 and the actual rotation angle obtained in S1. Specifically, when the response speed of the drive motor is fast, the steering delay of the vehicle can be reduced; when the actual rotation angle reaches the required steering angle, the speed difference of the drive motors of each drive wheel is zero, in other words, the speed difference of the drive wheels is zero.

[0073] In front-wheel drive mode, when the speed V1 of the front frame is determined, the two front wheels can be controlled to accelerate and decelerate separately based on the selected rate of change of the front frame speed V1. When the actual rotation angle reaches the required steering angle, the two front wheels are driven at the same speed V1. Preferably, the coefficient of the control rate of change of the two front wheels is 0.5.

[0074] In four-wheel drive mode, when the speed V1 of the front frame is determined, the speed difference V between the rear wheels can be calculated. delta2 With the rear frame's travel speed V2, at a selected rate of change, the two front wheels can be controlled to accelerate and decelerate separately based on the front frame's speed V1; similarly, the two rear wheels can be controlled to accelerate and decelerate separately based on the rear frame's speed V2. When the actual rotation angle reaches the required steering angle, the two front wheels are driven at the same speed V1, and the two rear wheels are driven at the same speed V2. Preferably, the coefficients of the control change rates for the two front wheels and the two rear wheels are both preferably 0.5.

[0075] This invention improves vehicle steering response speed by converting the steering demand angle into the rotational speed control of each drive wheel. Combined with steering via the hinge point between the front and rear frames, it enhances vehicle steering agility. It should be noted that when the rotational speed response of the drive wheels is sufficiently fast, the steering demand angle is correlated with the rotational speed of the drive wheels. Furthermore, the names "front wheel," "front frame," etc., are merely for ease of explanation; based on the vehicle's direction of travel, the parts at the front are the front wheels and front frame, and the corresponding parts are the rear frame and rear wheels.

[0076] This invention can be a system, apparatus, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of the invention.

[0077] Computer-readable storage media can be tangible devices that hold and store instructions for use by an instruction execution device. Computer-readable storage media can be, for example, including but not limited to, electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination thereof.

[0078] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A control method for a new energy vehicle steering chassis, the steering chassis comprising: A front frame, a rear frame, a front axle assembly and a rear axle assembly, wherein the front frame is connected with the front axle assembly, the rear frame is connected with the rear axle assembly, both ends of the front axle assembly and the rear axle assembly are respectively provided with a driving motor, and the driving motor is used for driving the wheels to rotate in a fixed direction, characterized in that the steering chassis further comprises an angle sensor assembly; the front frame and the rear frame are rotatably connected, and the angle sensor assembly is used for detecting the horizontal rotation angle between the front frame and the rear frame; and the control method comprises: S1, obtaining the forward speed of the current vehicle, the steering demand angle and the actual rotation angle sensed by the angle sensor assembly, wherein the actual rotation angle is the angle of the front frame and the rear frame rotating around the rotation point in the forward direction; S2, determining the driving speed difference between the power wheels in the driving mode based on the current driving mode of the vehicle, the pre-configured vehicle steering parameters and the vehicle speed and the steering demand angle obtained in S1; the driving mode comprises a four-wheel drive mode and a front drive mode; in the four-wheel drive mode, S2 comprises: S21'', determining the driving speed difference between the front wheels and the driving speed difference between the rear wheels in the four-wheel drive mode according to the pre-configured vehicle steering parameters and the vehicle speed and the steering demand angle obtained in S1, wherein the vehicle speed obtained in S1 is taken as the driving speed of the front frame; determining the driving speed difference between the front wheels in the four-wheel drive mode based on the steering demand angle; calculating the driving speed difference between the rear wheels and the driving speed of the rear frame based on the driving speed of the front frame, the steering demand angle and the pre-configured vehicle steering parameters; and determining the driving speed difference between the front wheels and the driving speed difference between the rear wheels in the four-wheel drive mode and the driving speed of the rear frame in S21'' by the following rules: L2 x (V delta2 / D2) = V1 x sin(θ) - L1 x (V dalta1 / D1) x cos(θ) V2 = V1 x cos(θ) + L1 x (V delta1 / D1) x sin(θ) wherein L2 represents a distance between a rear wheel axle and a rotation point between the front frame and the rear frame, V delta2 represents a difference in travel speed between the rear wheels, D2 represents a wheel track between the left rear wheel and the right rear wheel, V1 represents a travel speed of the front frame, V2 represents a travel speed of the rear frame, θ represents a steering demand angle, D1 represents a wheel track between the left front wheel and the right front wheel, and L1 represents a distance between a front wheel axle and a rotation point. in the front drive mode, S2 comprises: S21', determining the driving speed difference between the left front wheel and the right front wheel in the front drive mode according to the steering demand angle, and determining the driving speed difference between the left front wheel and the right front wheel in the front drive mode by the following rules: determining the driving speed difference according to the obtained steering demand angle and using the pre-configured conversion corresponding table between the steering demand angle and the driving speed difference; S3, controlling the rotation speed of the driving motor in the driving mode according to the driving speed difference determined in S2 and the actual rotation angle obtained in S1; S3 comprises: S31', controlling the rotation speed of the driving motor in the front drive mode according to the driving speed difference determined in S21' and the actual rotation angle obtained in S1; wherein the left front wheel driving motor is controlled to increase the corresponding rotation speed of the driving speed difference on the basis of the driving speed of the front frame, the right front wheel driving motor is controlled to reduce the corresponding rotation speed of the driving speed difference on the basis of the driving speed of the front frame, or the left front wheel driving motor is controlled to reduce the corresponding rotation speed of the driving speed difference on the basis of the driving speed of the front frame, and the right front wheel driving motor is controlled to increase the corresponding rotation speed of the driving speed difference on the basis of the driving speed of the front frame, until the actual rotation angle reaches the steering demand angle.

2. The control method according to claim 1, characterized by, In the S31', the rotation speed corresponding to the driving speed difference is obtained by the following rules: Φ1= V delta1 / D1 wherein Φ1 represents a rotational speed corresponding to the difference in travel speed, V delta1 represents the difference in travel speed, D1 represents the wheel track between the left front wheel and the right front wheel, represents the rate of change of the front wheel motor drive rotational speed.

3. The control method according to claim 1, characterized by, The S3 comprises: S31'', controlling the rotation speed of the driving motor in the front drive mode according to the driving speed difference of the front frame determined in the S21'' and the actual rotation angle obtained in the S1; wherein, simultaneously, the left front wheel driving motor is controlled to increase the rotation speed corresponding to the driving speed difference of the front frame on the basis of the current driving speed, the right front wheel driving motor is controlled to decrease the rotation speed corresponding to the driving speed difference of the front frame on the basis of the current driving speed, the left rear wheel driving motor is controlled to decrease the rotation speed corresponding to the driving speed difference of the rear frame on the basis of the driving speed of the rear frame, and the right rear wheel driving motor is controlled to increase the rotation speed corresponding to the driving speed difference of the rear frame on the basis of the driving speed of the rear frame, until the actual rotation angle reaches the steering demand angle. Or, simultaneously, the left front wheel driving motor is controlled to decrease the rotation speed corresponding to the driving speed difference of the front frame on the basis of the current driving speed, the right front wheel driving motor is controlled to increase the rotation speed corresponding to the driving speed difference of the front frame on the basis of the current driving speed, the left rear wheel driving motor is controlled to increase the rotation speed corresponding to the driving speed difference of the rear frame on the basis of the current driving speed, and the right rear wheel driving motor is controlled to decrease the rotation speed corresponding to the driving speed difference of the rear frame on the basis of the current driving speed, until the actual rotation angle reaches the steering demand angle.

4. The control method according to claim 3, characterized by In the S31'', the rotation speed corresponding to the driving speed difference of the rear frame is obtained by the following rules: Φ2= V delta2 / D2 wherein Φ2 represents a rotational speed corresponding to a difference in travel speed of the rear frame, V delta2 represents V delta2 represents a difference in travel speed between the rear wheels, D2 represents a wheel track between the left and right rear wheels, represents a rate of change of the rotational speed of the rear wheel motor drive.

5. A control device for a new energy vehicle steering chassis, characterized in that, The control device comprises a controller, and the controller executes the control method according to any one of claims 1-4.

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