New energy vehicle and motor position recognition device and method for wheel drive system thereof

Abstract

The application discloses a new energy vehicle and a motor position recognition device and method of a wheel-side driving system thereof. The recognition device comprises a first sensor for collecting first-side actual wheel speed signals and second-side actual wheel speed signals; a second sensor for collecting a steering wheel rotation angle signal; and a controller for calculating an inner-outer wheel speed proportion factor according to the steering wheel rotation angle signal, calculating inner-side theoretical wheel speed and outer-side theoretical wheel speed according to the proportion factor and a current driving speed, and judging whether the first side and the second side correspond to inner-side wheels or outer-side wheels according to the inner-side theoretical wheel speed, the outer-side theoretical wheel speed, the first-side actual wheel speed signals and the second-side actual wheel speed signals, and further judging whether the first side and the second side correspond to inner-side driving motors or outer-side driving motors. The application can solve the problem of driving motor wiring dislocation without changing the wiring harness.

Description

Technical Field

[0001] This invention belongs to the field of wheel-side drive technology, and particularly relates to a new energy vehicle and its wheel-side drive system motor position identification device and method. Background Technology

[0002] Wheel-side drive systems offer a solution for creating fully flat, low-floor, low-entry, high-capacity new energy urban buses. Compared to a central direct-drive system, the wheel-side drive system eliminates the central drive shaft, with the drive motor deeply coupled to the drive wheels, forming the wheel-side drive system assembly to propel the vehicle. However, because the left and right drive motors drive the left and right wheels respectively, and their driver programs are integrated into the control assembly, misalignment of the high-voltage wiring harnesses (U, V, W) of the drive motors is highly likely, leading to abnormal operation of the drive wheel program and causing vehicle safety issues.

[0003] Therefore, how to achieve adaptive recognition of the drive motor position is a key problem that needs to be solved in the control of wheel-side drive systems. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for identifying the position of motors in new energy vehicles and their wheel-side drive systems, so as to solve the problem of misalignment of drive motor wiring caused by the inability to distinguish between left and right drive motors, which in turn leads to vehicle driving safety issues.

[0005] This invention solves the above-mentioned technical problems through the following technical solution: a wheel-side drive system motor position recognition device, comprising:

[0006] The first sensor is used to collect the actual wheel speed signal on the first side and the actual wheel speed signal on the second side.

[0007] The second sensor is used to collect the steering wheel angle signal;

[0008] The controller is used to calculate the scaling factor of the inner and outer wheel speeds based on the steering wheel angle signal; calculate the theoretical inner wheel speed and the theoretical outer wheel speed based on the scaling factor and the current driving speed; determine whether the wheels corresponding to the first and second sides are inner wheels or outer wheels based on the theoretical inner wheel speed, the theoretical outer wheel speed, the actual wheel speed signal of the first side and the actual wheel speed signal of the second side, and further determine whether the motors corresponding to the first and second sides are inner drive motors or outer drive motors.

[0009] The inner side refers to the side that rotates in the same direction as the steering wheel, while the outer side refers to the side that rotates in the opposite direction to the steering wheel.

[0010] Furthermore, the first sensor includes a first wheel speed sensor and a second wheel speed sensor, both of which are ABS wheel speed sensors. The two ABS wheel speed sensors are used to collect the actual wheel speed signal on the first side and the actual wheel speed signal on the second side, respectively.

[0011] Furthermore, the second sensor is a steering angle sensor, which is located at the steering wheel.

[0012] Based on the same concept, the present invention also provides a new energy vehicle, the vehicle including the wheel-side drive system motor position recognition device as described above.

[0013] Based on the same concept, the present invention also provides a method for identifying the position of a motor in a wheel-side drive system, comprising:

[0014] When the vehicle is turning and moving, the steering wheel angle signal, the actual wheel speed signal on the first side, the actual wheel speed signal on the second side, and the current driving speed are acquired in real time.

[0015] Calculate the scaling factor of the inner and outer wheel speeds based on the steering wheel angle signal;

[0016] Calculate the theoretical wheel speeds of the inner and outer sides based on the aforementioned scaling factor and the current driving speed;

[0017] When the actual wheel speed signal on the first side is close to the theoretical wheel speed on the inner side or the theoretical wheel speed on the outer side, the wheel corresponding to the first side is the inner wheel or the outer wheel, the wheel corresponding to the second side is the outer wheel or the inner wheel, the motor corresponding to the first side is the inner drive motor or the outer drive motor, and the motor corresponding to the second side is the outer drive motor or the inner drive motor.

[0018] Alternatively, when the actual wheel speed signal on the second side is close to the theoretical wheel speed on the inner side or the theoretical wheel speed on the outer side, the wheel corresponding to the second side is the inner wheel or the outer wheel, the wheel corresponding to the first side is the outer wheel or the inner wheel, the motor corresponding to the second side is the inner drive motor or the outer drive motor, and the motor corresponding to the first side is the outer drive motor or the inner drive motor.

[0019] The inner side refers to the side that rotates in the same direction as the steering wheel, while the outer side refers to the side that rotates in the opposite direction to the steering wheel.

[0020] Furthermore, the formula for calculating the proportionality factor of the inner and outer wheel speeds is as follows:

[0021]

[0022] Where r represents the proportionality factor of the inner and outer wheel speeds, R in R represents the turning radius of the inner wheel on the rear axle.out This indicates the turning radius of the outermost wheel on the rear axle, where L represents the wheelbase and H represents the track width of the rear wheels. This represents the average steering angle of the inner and outer wheels of the front axle, δ represents the steering wheel angle signal, and α represents the steering coefficient.

[0023] Furthermore, the formula for calculating the theoretical inner wheel speed is as follows:

[0024]

[0025] Among them, v in,ref The inner wheel speed is represented by r, which is the ratio factor between the inner and outer wheel speeds, and v is the current driving speed.

[0026] The formula for calculating the theoretical speed of the outer wheel is:

[0027]

[0028] Among them, v out,ref This indicates the theoretical speed of the outer wheel.

[0029] Furthermore, the steering wheel has a turning angle greater than 180° and the vehicle speed is greater than 15 km / h.

[0030] Beneficial effects

[0031] Compared with the prior art, the advantages of the present invention are as follows:

[0032] This invention calculates the theoretical wheel speeds of the inner and outer wheels based on the scaling factor of the inner and outer wheel speeds. Then, it compares these theoretical wheel speeds with the actual wheel speed signals to identify whether the drive motors on both sides are inner or outer drive motors, thus achieving motor position identification. When the identified motor position does not correspond to the motor driver program in the control assembly, the motor driver program in the control assembly is adjusted to match the motor position. This solves the problem of misaligned drive motor wiring caused by the inability to distinguish between left and right drive motors without rewiring the wiring harness, reducing wiring harness rewiring costs and improving the robustness of the motor control logic and vehicle operating safety. Attached Figure Description

[0033] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a diagram of the wheel-side drive system architecture in an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the Ackermann steering principle in an embodiment of the present invention;

[0036] Figure 3 This is a flowchart of the method for identifying the motor position of the wheel-side drive system in an embodiment of the present invention. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The technical solutions of this application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0039] Example 1

[0040] like Figure 1 As shown, the steering wheel is connected to the front axle between the two front wheels via a steering shaft. The front axle is connected to the rear axle via a connecting shaft. Rear wheels are located at both ends of the rear axle, and wheel-side drive assemblies are installed at each of the two rear wheels. Each wheel-side drive assembly includes a drive motor and a reducer. The drive motor drives the corresponding rear wheel to rotate, thus propelling the vehicle and also enabling regenerative braking. A yaw rate sensor is used to collect the yaw rate at the vehicle's center of gravity in real time to determine if the vehicle is at risk of instability.

[0041] The wheel-side drive system motor position identification device provided in this embodiment of the invention includes a first sensor, a second sensor, and a controller. The first sensor is used to collect actual wheel speed signals of a first side and a second side; the second sensor is used to collect steering wheel angle signals; the controller is used to calculate the scaling factor of the inner and outer wheel speeds based on the steering wheel angle signals; calculate the theoretical inner wheel speed and the theoretical outer wheel speed based on the scaling factor and the current driving speed; determine whether the wheels corresponding to the first side and the second side are inner wheels or outer wheels based on the theoretical inner wheel speed, the theoretical outer wheel speed, the actual wheel speed signals of the first side and the second side, and then determine whether the motors corresponding to the first side and the second side are inner drive motors or outer drive motors.

[0042] In a specific embodiment of the present invention, the first sensor includes a first wheel speed sensor and a second wheel speed sensor. Both the first wheel speed sensor and the second wheel speed sensor are ABS wheel speed sensors. The ABS wheel speed sensor can collect high-precision wheel speed signals in real time. The two ABS wheel speed sensors are respectively installed on the two rear wheels and are used to collect the actual wheel speed signals of the first side and the second side, respectively, that is, to collect the actual wheel speed signals of the two rear wheels.

[0043] In a specific embodiment of the present invention, the second sensor is a steering angle sensor, which is located at the steering wheel. The steering angle sensor collects the steering wheel angle signal in real time, senses the driver's driving intention, and can determine whether the vehicle is driving in a straight line or turning.

[0044] In a specific embodiment of the present invention, the proportional factor of the inner and outer wheel speeds is calculated based on the Ackermann steering principle. For example... Figure 2 As shown, when a vehicle turns, the steering angles of the inner and outer wheels are not consistent and typically differ by 2–4°. This results in the inner wheel having a smaller turning radius than the outer wheel, reducing tire wear. The Ackermann steering principle states that during vehicle movement (straight-line driving or turning), the trajectory of each wheel must perfectly conform to its natural motion trajectory, ensuring pure rolling without slippage between the tire and the ground. In a vehicle conforming to the Ackermann steering principle, when driving straight, the axes between the two front wheels and the two rear wheels are parallel and perpendicular to the vehicle's longitudinal center plane; during turning, all wheels must roll in a circle around an instantaneous center point O.

[0045] According to the Ackermann steering principle, all wheels move in a circle around the instantaneous center O, where A, B, C, and D are the center points of their respective wheels, ∠AOC is the steering angle of the inner wheel on the front axle, ∠BOD is the steering angle of the outer wheel on the front axle, and ∠EOF is the average steering angle of the inner and outer wheels on the front axle. The symbols indicate that EF is the wheelbase (the vertical distance between the front and rear axles), represented by the character L; CD is the track width (the distance between the two rear wheels), represented by the character H; and the turning radius of the inner wheel on the rear axle is OC, represented by the character R. in The turning radius of the outer wheel on the rear axle is OD, represented by the character R. out Let be the representation. Then the following geometric relationship exists:

[0046]

[0047] Assuming that both the inner and outer wheels undergo pure rolling motion during steering, then:

[0048] v in =Rin w in (3)

[0049] v out =R out w out (4)

[0050] Among them, v in The wheel speed, v, is the speed at the center of the inner wheel on the rear axle. out w represents the wheel speed at the center of the outermost wheel on the rear axle. in w represents the angular velocity of the inner wheel of the rear axle. out This indicates the angular velocity of the outer wheel on the rear axle.

[0051] Assuming the vehicle is a rigid body, then:

[0052] w in =w out (5)

[0053] The wheel speeds of the inner and outer wheels satisfy the following relationship:

[0054]

[0055] Here, r represents the scaling factor for the inner and outer wheel speeds. Therefore, when calculating the scaling factor for the inner and outer wheel speeds, the average steering angle of the inner and outer wheels on the front axle is first calculated based on the steering wheel angle signal δ. Right now α represents the steering coefficient (i.e., the conversion coefficient between the steering wheel angle and the wheel steering angle); then the scaling factor r can be calculated according to formulas (1), (2) and (6).

[0056] Based on the principle of differential control, under steering or uneven road conditions:

[0057] v in +v out =2v (7)

[0058] Where v represents the vehicle's speed.

[0059] According to formulas (6) and (7):

[0060]

[0061] Among them, v in,ref This represents the theoretical wheel speed on the inside, v. out,ref This represents the theoretical wheel speed on the outermost wheel. When the vehicle is traveling in a straight line, v... out,ref =v in,ref When the vehicle turns, v out,ref >v in,refThat is, the theoretical inner wheel speed v can be calculated using formulas (8) and (9). in,ref Theoretical wheel speed v on the outer side out,ref .

[0062] In this embodiment, the two wheel-side drive assemblies share a single control assembly. This control assembly integrates inverter modules for both drive motor controllers, as well as an auxiliary power control system, such as an oil pump and an air pump. The controller of this invention can either be a vehicle-wide controller, eliminating the need for an additional controller and reducing costs, or it can be configured with an additional controller.

[0063] This invention utilizes a controller to calculate the scaling factor of the inner and outer wheel speeds based on the steering wheel angle signal; it then calculates the theoretical inner and outer wheel speeds based on the scaling factor and the current driving speed; when the actual wheel speed signal on the first side is close to the theoretical inner wheel speed (or the theoretical outer wheel speed), the wheel corresponding to the first side is designated as the inner wheel (or outer wheel), the wheel corresponding to the second side is designated as the outer wheel (or inner wheel), the motor corresponding to the first side is designated as the inner drive motor (or outer drive motor), and the motor corresponding to the second side is designated as the outer drive motor (or inner drive motor); or, when the actual wheel speed signal on the second side is close to the theoretical inner wheel speed (or outer drive speed), the wheel corresponding to the second side is designated as the inner wheel (or outer wheel), the wheel corresponding to the first side is designated as the outer wheel (or inner wheel), the motor corresponding to the second side is designated as the inner drive motor (or outer drive motor), and the motor corresponding to the first side is designated as the outer drive motor (or inner drive motor).

[0064] Based on the Ackermann steering principle and the differential principle, this invention shows that when a vehicle is turning, the speed of the inner wheel is always less than that of the outer wheel. By comparing the speed of the inner and outer wheels with the steering wheel in real time, the position of the drive motor is identified, that is, which side of the drive motor is the inner drive motor and which side of the drive motor is the outer drive motor.

[0065] When the inner drive motor matches its corresponding driver program, and the outer drive motor matches its corresponding driver program, it indicates no wiring error. When the inner drive motor does not match its corresponding driver program, it indicates that the inner drive motor is not properly matched to the driver program corresponding to the outer drive motor, and vice versa. Adjusting the positions of the two motor driver programs in the control assembly so that the inner drive motor matches its corresponding driver program and the outer drive motor matches its corresponding driver program allows for motor position adaptation without rewiring, thus resolving the problem of incorrect drive motor wiring.

[0066] The inside refers to the side that rotates in the same direction as the steering wheel, while the outside refers to the side that rotates in the opposite direction. For example, when turning the steering wheel to the left, the left side is the inside and the right side is the outside; when turning the steering wheel to the right, the right side is the inside and the left side is the outside.

[0067] Example 2

[0068] like Figure 3 As shown, the method for identifying the motor position of a wheel-side drive system provided in this embodiment of the invention includes the following steps:

[0069] Step S1: Turn the steering wheel to the left or right and accelerate to put the vehicle into motion.

[0070] For easy identification, turn the steering wheel more than 180° to the left or right, and the vehicle speed is 15 km / h.

[0071] Step S2: Real-time acquisition of steering wheel angle signal, actual wheel speed signal on the first side, actual wheel speed signal on the second side, and current driving speed.

[0072] Step S3: Calculate the proportional factor of the inner and outer wheel speeds based on the steering wheel angle signal.

[0073] In a specific embodiment of the present invention, the average steering angle of the inner and outer wheels of the front axle is first calculated based on the steering wheel angle signal δ. Right now α represents the steering coefficient; then the scaling factor r can be calculated according to formulas (1), (2) and (6).

[0074] Step S4: Calculate the theoretical inner wheel speed v based on the scaling factor r and the current driving speed v. in,ref Theoretical wheel speed v on the outer side out,ref For example, formulas (8) and (9).

[0075] Step S5: Based on the theoretical inner wheel speed v in,ref Theoretical wheel speed v on the outer side out,ref The actual wheel speed signals of the first and second sides are used to determine whether the wheels corresponding to the first and second sides are inner or outer wheels, and then to determine whether the motors corresponding to the first and second sides are inner drive motors or outer drive motors.

[0076] When the actual wheel speed signal on the first side is different from the theoretical wheel speed v on the inner side in,re f (or the theoretical speed of the outer wheel v) out,refWhen the wheels on the first side approach each other, the wheel corresponding to the first side becomes the inner wheel (or outer wheel), and the wheel corresponding to the second side becomes the outer wheel (or inner wheel). The motor corresponding to the first side becomes the inner drive motor (or outer drive motor), and the motor corresponding to the second side becomes the outer drive motor (or inner drive motor); or, when the actual wheel speed signal of the second side is close to the theoretical wheel speed v of the inner side... in,ref (or theoretical wheel speed v on the outer side) out,ref When approaching, the wheel corresponding to the second side is the inner wheel (or outer wheel), the wheel corresponding to the first side is the outer wheel (or inner wheel), the motor corresponding to the second side is the inner drive motor (or outer drive motor), and the motor corresponding to the first side is the outer drive motor (or inner drive motor).

[0077] When the inner drive motor matches its corresponding driver program, and the outer drive motor matches its corresponding driver program, it indicates no wiring error. When the inner drive motor does not match its corresponding driver program, and the outer drive motor does not match its corresponding driver program, it indicates that the inner drive motor is not properly matched to the driver program corresponding to the outer drive motor, and vice versa. Adjusting the positions of the two motor driver programs in the control assembly so that the inner drive motor matches its corresponding driver program and the outer drive motor matches its corresponding driver program allows for motor position adaptation without rewiring, thus resolving the problem of drive motor wiring errors. This invention effectively reduces wiring harness rewiring costs and improves the robustness of control logic and vehicle operation safety by adaptively identifying motor positions and adjusting motor driver programs via software.

[0078] The above description only discloses specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or modifications that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A motor position recognition device for a wheel-side drive system, characterized in that, The recognition device comprises: a first sensor for collecting first-side actual wheel speed signals and second-side actual wheel speed signals; a second sensor for collecting steering wheel rotation angle signals; a controller for calculating the proportion factor of the inner and outer wheel speeds according to the steering wheel rotation angle signals, calculating the inner and outer theoretical wheel speeds according to the proportion factor and the current driving speed, and comparing the first-side actual wheel speed signals and the second-side actual wheel speed signals with the inner and outer theoretical wheel speeds respectively; if the first-side actual wheel speed signals are close to the inner theoretical wheel speed, it is determined that the wheel corresponding to the first side is the inner wheel, the motor corresponding to the first side is the inner drive motor, and the wheel corresponding to the second side is the outer wheel, and the motor corresponding to the second side is the outer drive motor; or, if the first-side actual wheel speed signals are close to the outer theoretical wheel speed, it is determined that the wheel corresponding to the first side is the outer wheel, the motor corresponding to the first side is the outer drive motor, and the wheel corresponding to the second side is the inner wheel, and the motor corresponding to the second side is the inner drive motor; wherein the inner side refers to the side in the same direction as the steering wheel rotation, and the outer side refers to the side in the opposite direction as the steering wheel rotation.

2. The wheel drive system motor position recognition device according to claim 1, characterized by, The first sensor comprises a first wheel speed sensor and a second wheel speed sensor, both of which are ABS wheel speed sensors, and the two ABS wheel speed sensors are used for collecting the first-side actual wheel speed signals and the second-side actual wheel speed signals respectively.

3. The wheel drive system motor position recognition device according to claim 1, characterized by, The second sensor is a rotation angle sensor, which is arranged at the steering wheel.

4. The wheel drive system motor position recognition apparatus according to claim 1, characterized by, The calculation formula of the proportion factor of the inner and outer wheel speeds is: where r represents a proportional factor of the inside and outside wheel speeds, R in represents the turning radius of the inside rear wheel, R out represents the turning radius of the outside rear wheel, L represents the wheel base, and H represents the track of the rear wheel, represents the average turning angle of the inside and outside front wheels, δ represents the turning angle signal of the steering wheel, and α represents the turning coefficient.

5. The wheel drive system motor position recognition device according to any one of claims 1 to 4, characterized by The calculation formula of the inner theoretical wheel speed is: where v in,ref represents the inside theoretical wheel speed, r represents a proportional factor of the inside and outside wheel speeds, and v represents the current driving speed; The calculation formula of the outer theoretical wheel speed is: where v out,ref represents the outside theoretical wheel speed.

6. A new energy vehicle, characterized in that, The vehicle comprises the wheel drive system motor position recognition device according to any one of claims 1 to 5.

7. A wheel drive system motor position recognition method characterized by comprising: The recognition method comprises: when the vehicle is turning and driving, the steering wheel rotation angle signals, the first-side actual wheel speed signals, the second-side actual wheel speed signals and the current driving speed are acquired in real time; the proportion factor of the inner and outer wheel speeds is calculated according to the steering wheel rotation angle signals; the inner and outer theoretical wheel speeds are calculated according to the proportion factor and the current driving speed; the first-side actual wheel speed signals and the second-side actual wheel speed signals are compared with the inner and outer theoretical wheel speeds respectively; if the first-side actual wheel speed signals are close to the inner theoretical wheel speed, it is determined that the wheel corresponding to the first side is the inner wheel, the motor corresponding to the first side is the inner drive motor, and the wheel corresponding to the second side is the outer wheel, and the motor corresponding to the second side is the outer drive motor; or, if the first-side actual wheel speed signals are close to the outer theoretical wheel speed, it is determined that the wheel corresponding to the first side is the outer wheel, the motor corresponding to the first side is the outer drive motor, and the wheel corresponding to the second side is the inner wheel, and the motor corresponding to the second side is the inner drive motor. The inner side refers to the side same as the rotating direction of the steering wheel, and the outer side refers to the side opposite to the rotating direction of the steering wheel.

8. The wheel drive system motor position recognition method according to claim 7, characterized by, The calculation formula of the proportional factor of the inner and outer wheel speeds is: where r represents a proportional factor of the inside and outside wheel speeds, R in represents the turning radius of the inside wheel of the rear axle, R out represents the turning radius of the outside wheel of the rear axle, L represents the wheel base, and H represents the track of the rear wheel, represents the average turning angle of the inside and outside wheels of the front axle, δ represents the turning angle signal of the steering wheel, and α represents the turning coefficient.

9. The wheel drive system motor position recognition method according to claim 7, characterized by, The calculation formula of the inner theoretical wheel speed is: where v in,ref represents the inside theoretical wheel speed, r represents a proportional factor of the inside and outside wheel speeds, and v represents the current driving speed; The calculation formula of the outer theoretical wheel speed is: where v out,ref represents the outside theoretical wheel speed.

10. The wheel drive system motor position recognition method according to any one of claims 7 to 9, characterized by, The rotating angle of the steering wheel is greater than 180°, and the vehicle driving speed is greater than 15 km / h.

Images