New energy vehicle, and electric-motor position identification apparatus and method for wheel-side drive system of new energy vehicle

Abstract

Disclosed in the present invention are a new energy vehicle, and an electric-motor position identification apparatus and method for a wheel-side drive system of the new energy vehicle. The electric-motor position identification apparatus comprises: a first sensor and a second sensor, which are respectively used for collecting a first-side actual wheel speed signal and a second-side actual wheel speed signal; a third sensor, which is used for collecting a steering angle signal of a steering wheel; and a controller, which is used for calculating a ratio factor of wheel speeds of inner and outer wheels on the basis of the steering angle signal of the steering wheel, calculating a theoretical inner wheel speed and a theoretical outer wheel speed on the basis of the ratio factor and the current traveling speed, and determining, on the basis of the theoretical inner wheel speed, the theoretical outer wheel speed, the first-side actual wheel speed signal and the second-side actual wheel speed signal, whether a wheel corresponding to a first side or a second side is an inner wheel or an outer wheel, so as to determine whether an electric motor corresponding to the first side or the second side is an inner drive electric-motor or an outer drive electric-motor. The present invention can solve the problem of misaligned wiring of a drive electric-motor without requiring wire harness modifications.

Description

New energy vehicles and their wheel-side drive system motor position recognition devices and methods 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, and improve vehicle driving safety.

[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;

[0007] The second sensor is used to collect the actual wheel speed signal on the second side;

[0008] The third sensor is used to collect the steering wheel angle signal;

[0009] The controller is used to determine the turning radius of the inner and outer wheels based on the steering wheel angle signal, calculate the wheel speed scaling factor of the inner and outer wheels based on the turning radius of the inner and outer wheels, calculate the theoretical wheel speed of the inner wheel and the theoretical wheel speed of the outer wheel based on the scaling factor and the current driving speed, and determine whether the wheels corresponding to the first side and the second side are inner wheels or outer wheels based on the theoretical wheel speed of the inner wheel, the theoretical wheel speed of the outer wheel, 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 side and the second side are inner drive motors or outer drive motors.

[0010] The inner side refers to the side in which the steering wheel is turned, while the outer side refers to the side away from the direction of the steering wheel's rotation.

[0011] This invention applies the Ackermann steering principle to motor position identification. It calculates the theoretical wheel speeds of the inner and outer wheels based on a scaling factor, and then compares these theoretical speeds with the actual wheel speed signals to identify whether the drive motors on either side are the inner or outer drive motors, achieving adaptive and accurate motor position identification. This invention is simple to implement and effectively solves the problem of misaligned drive motor wiring caused by the inability of existing technologies to distinguish between left and right drive motors, thus improving vehicle driving safety.

[0012] Furthermore, both the first and second sensors are ABS wheel speed sensors.

[0013] Furthermore, the third sensor is a steering angle sensor, which is located at the steering wheel.

[0014] 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.

[0015] 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:

[0016] 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.

[0017] The steering radius of the inner and outer wheels is determined based on the steering wheel angle signal, and the proportional factor of the wheel speed of the inner and outer wheels is calculated based on the steering radius of the inner and outer wheels.

[0018] Calculate the theoretical wheel speeds of the inner and outer sides based on the aforementioned scaling factor and the current driving speed;

[0019] 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.

[0020] 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.

[0021] The inner side refers to the side in which the steering wheel is turned, while the outer side refers to the side away from the direction of the steering wheel's rotation.

[0022] Furthermore, the formula for calculating the proportionality factor of the inner and outer wheel speeds is as follows:

[0023] ;

[0024] , , ;

[0025] in, The scaling factor representing the wheel speeds of the inner and outer wheels. Indicates the turning radius of the inner wheel on the rear axle. This indicates the turning radius of the outer wheel on the rear axle. Indicates wheelbase. Indicates the track width of the rear wheels. This represents the average steering angle of the inner and outer wheels on the front axle. Indicates the steering wheel angle signal. This indicates the steering coefficient.

[0026] Furthermore, the formula for calculating the theoretical inner wheel speed is as follows:

[0027] ;

[0028] in, This indicates the theoretical wheel speed on the inside. The scaling factor representing the wheel speeds of the inner and outer wheels. Indicates the current driving speed;

[0029] The formula for calculating the theoretical speed of the outer wheel is:

[0030] ;

[0031] in, This indicates the theoretical speed of the outer wheel.

[0032] Furthermore, the steering wheel has a turning angle greater than 180° and the vehicle speed is greater than 15 km / h. Beneficial effects

[0033] Compared with the prior art, the advantages of the present invention are as follows:

[0034] This invention applies the Ackermann steering principle to motor position identification. It calculates the theoretical wheel speeds of the inner and outer wheels based on the scaling factors of the inner and outer wheel speeds. These theoretical speeds are then compared with the actual wheel speed signals to identify whether the drive motors on either side are the 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, only the motor driver program in the control assembly needs to be 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

[0035] To more clearly illustrate the technical solution of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the 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.

[0036] Figure 1 is a diagram of the wheel-side drive system architecture in an embodiment of the present invention;

[0037] Figure 2 is a schematic diagram of the Ackermann steering principle in an embodiment of the present invention;

[0038] Figure 3 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

[0039] 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.

[0040] The technical solutions of this application will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. Example

[0041] As shown in Figure 1, 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, thereby 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, thereby determining whether the vehicle is at risk of instability.

[0042] The wheel-side drive system motor position identification device provided in this embodiment of the invention includes a first sensor, a second sensor, a third sensor, and a controller. The first and second sensors are used to collect actual wheel speed signals of a first side and a second side, respectively. The third 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. Based on the scaling factor and the current driving speed, it calculates the theoretical inner wheel speed and the theoretical outer wheel speed. Based on the theoretical inner wheel speed, the theoretical outer wheel speed, the actual wheel speed signals of the first and second sides, it determines whether the wheels corresponding to the first and second sides are inner or outer wheels, and then determines whether the motors corresponding to the first and second sides are inner drive motors or outer drive motors.

[0043] In one specific embodiment, both the first sensor and the second sensor are ABS wheel speed sensors, which can acquire 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 acquire the actual wheel speed signals of the first side and the second side, respectively, that is, to acquire the actual wheel speed signals of the two rear wheels.

[0044] In one specific implementation, the third 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 traveling in a straight line or turning.

[0045] In one specific implementation, the proportional factor of the inner and outer wheel speeds is calculated based on the Ackermann steering principle. As shown in Figure 2, when the vehicle turns, the steering angles of the inner and outer wheels are not consistent and typically differ by 2–4°, making the turning radius of the inner wheel smaller than that of the outer wheel, thus reducing tire wear. The Ackermann steering principle states that during vehicle travel (straight-line or turning), the trajectory of each wheel must perfectly conform to its natural trajectory, ensuring pure rolling without slippage between the tire and the ground. In a vehicle conforming to the Ackermann steering principle, when traveling straight, the axis between the two front wheels is parallel to the axis between the two rear wheels and perpendicular to the vehicle's longitudinal center plane; during turning, all wheels must roll in a circle around an instantaneous center point O.

[0046] 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 the corresponding wheels. This refers to the steering angle of the inner wheel on the front axle. This refers to the steering angle of the outer wheel on the front axle. The average steering angle of the inner and outer wheels of the front axle is given by... 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. The turning radius of the inner wheel on the rear axle is OC, represented by the character... The turning radius of the outer wheel on the rear axle is OD, expressed in characters. Let be the representation. Then the following geometric relationship exists:

[0047] (1)

[0048] (2)

[0049] Assuming that both the inner and outer wheels undergo pure rolling motion during steering, then:

[0050] (3)

[0051] (4)

[0052] in, This indicates the wheel speed at the center of the inner wheel on the rear axle. This indicates the wheel speed at the center of the outermost wheel on the rear axle. Indicates the angular velocity of the inner wheel of the rear axle. This indicates the angular velocity of the outer wheel on the rear axle.

[0053] Assuming the vehicle is a rigid body, then:

[0054] (5)

[0055] The wheel speeds of the inner and outer wheels satisfy the following relationship:

[0056] (6)

[0057] in, This refers to the scaling factor representing the wheel speeds of the inner and outer wheels. Therefore, when calculating the scaling factor for the inner and outer wheel speeds, the steering wheel angle signal is used as the first reference. Calculate the average steering angle of the inner and outer wheels of the front axle. ,Right now , This represents the steering coefficient (i.e., the conversion coefficient between the steering wheel angle and the wheel steering angle); then, the scaling factor can be calculated according to formulas (1), (2), and (6). .

[0058] Based on the principle of differential control, under steering or uneven road conditions:

[0059] (7)

[0060] in, Indicates the vehicle's speed.

[0061] According to formulas (6) and (7):

[0062] (8)

[0063] (9)

[0064] in, This indicates the theoretical wheel speed on the inside. This indicates the theoretical speed of the outer wheel. When the vehicle is traveling in a straight line... When the vehicle turns and moves, That is, the theoretical inner wheel speed can be calculated according to formulas (8) and (9). Theoretical wheel speed on the outer side .

[0065] 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 be either a vehicle-wide controller or an additional controller. Using a vehicle-wide controller eliminates the need for an additional controller, reducing costs.

[0066] In this embodiment of the invention, the controller calculates the scaling factor of the inner and outer wheel speeds based on the steering wheel angle signal; it calculates the theoretical inner wheel speed and the theoretical outer wheel speed based on the scaling factor and the current driving speed; when the actual wheel speed signal of 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 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); or, when the actual wheel speed signal of the second side is close to the theoretical inner wheel speed (or the theoretical outer wheel speed), 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).

[0067] Based on the Ackermann steering principle and the differential principle, it is known 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 recognition of the drive motor is realized, that is, it is possible to identify which side of the drive motor is the inner drive motor and which side of the drive motor is the outer drive motor.

[0068] 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.

[0069] The inside refers to the side in which the steering wheel is turned, and the outside refers to the side away from the direction of steering wheel rotation. 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. Example

[0070] As shown in Figure 3, the method for identifying the motor position of a wheel-side drive system provided in this embodiment of the invention includes the following steps:

[0071] Step S1: Turn the steering wheel to the left or right and accelerate to put the vehicle into motion.

[0072] For easy identification, turn the steering wheel more than 180° to the left or right, and the vehicle speed is 15 km / h.

[0073] 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.

[0074] Step S3: Calculate the proportional factor of the inner and outer wheel speeds based on the steering wheel angle signal.

[0075] In a specific embodiment of the present invention, the steering wheel angle signal is first used as the basis for... Calculate the average steering angle of the inner and outer wheels of the front axle. ,Right now , The steering coefficient is represented by formula (1), (2), and (6); then the scaling factor can be calculated according to formulas (1), (2), and (6). .

[0076] Step S4: Based on the scaling factor Current driving speed Calculate the theoretical wheel speed on the inside Theoretical wheel speed on the outer side For example, formulas (8) and (9).

[0077] Step S5: Based on the theoretical wheel speed of the inner side Theoretical wheel speed on the outer side 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.

[0078] When the actual wheel speed signal on the first side matches the theoretical wheel speed on the inner side (or theoretical wheel speed on the outer side) When 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 on the second side is close to the theoretical wheel speed on the inner side... (or theoretical wheel speed on the outer side) 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).

[0079] 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 embodiment of the invention effectively reduces wiring harness rewiring costs and improves the robustness of the control logic and vehicle operation safety by using software adaptive motor position identification.

[0080] 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 drive system, characterized by, The method comprises the following steps: a first sensor is used to collect a first-side actual wheel speed signal; a second sensor is used to collect a second-side actual wheel speed signal; a third sensor is used to collect a steering wheel rotation angle signal; a controller is used to determine the steering radii of the inner and outer wheels according to the steering wheel rotation angle signal, to calculate a proportion factor of the inner and outer wheel speeds according to the steering radii of the inner and outer wheels, to calculate an inner-side theoretical wheel speed and an outer-side theoretical wheel speed according to the proportion factor and the current driving speed, and to determine the sides of the first and second sides of the corresponding wheels according to the difference between the actual wheel speed signal and the theoretical wheel speed, and to determine the sides of the first and second sides of the corresponding motors according to the sides of the wheels. The sides refer to the inner side or the outer side, the inner side refers to the side toward which the steering wheel rotates, and the outer side refers to the side away from the steering wheel rotation direction.

2. The wheel drive system motor position recognition device according to claim 1, characterized by, The first sensor and the second sensor are ABS wheel speed sensors.

3. The wheel drive system motor position recognition device according to claim 1, characterized by, The third 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: ； ， ， ； wherein a scale factor representing the inside and outside wheel speeds, denotes the steering radius of the rear inner wheel, represents the steering radius of the rear outside wheel, denotes the wheel base, representing the track of the rear wheel, denotes the average steering angle of the front inner and outer wheels, a steering angle signal representing the steering wheel angle, wherein K represents the steering 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-side theoretical wheel speed is: ； The calculation formula of the outer-side theoretical wheel speed is: ； wherein, represents the inside theory wheel speed, a scale factor representing the inside and outside wheel speeds, indicates the current driving speed, wherein Vout represents the outer-side theoretical wheel speed.

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

7. A method for identifying the position of a motor in a wheel-side drive system, characterized in that, The recognition method comprises the following steps: when the vehicle is steering, the steering wheel rotation angle signal, the first-side actual wheel speed signal, the second-side actual wheel speed signal, and the current driving speed are acquired in real time; the steering radii of the inner and outer wheels are determined according to the steering wheel rotation angle signal, and the proportion factor of the inner and outer wheel speeds is calculated according to the steering radii of the inner and outer wheels; the inner-side theoretical wheel speed and the outer-side theoretical wheel speed are calculated according to the proportion factor and the current driving speed; when the first-side actual wheel speed signal is close to the inner-side theoretical wheel speed or the outer-side theoretical wheel speed, 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; or, when the second-side actual wheel speed signal is close to the inner-side theoretical wheel speed or the outer-side theoretical wheel speed, 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. The sides refer to the inner side or the outer side, the inner side refers to the side toward which the steering wheel rotates, and the outer side refers to the side away from the steering wheel rotation direction.

8. The wheel drive system motor position recognition method according to claim 7, characterized by, The calculation formula of the proportion factor of the inner and outer wheel speeds is: ； ， ， ； wherein, a scale factor representing the inside and outside wheel speeds, denotes the steering radius of the rear inner wheel, represents the steering radius of the rear outside wheel, denotes the wheel base, representing the track of the rear wheel, denotes the average steering angle of the front inner and outer wheels, a steering angle signal indicative of a steering wheel angle, wherein K represents the steering coefficient.

9. The wheel drive system motor position recognition method according to claim 7, characterized by, The calculation formula of the inside theoretical wheel speed is: ​ wherein, represents the inside theory wheel speed, a scale factor representing the inside and outside wheel speeds, V represents the current driving speed. The calculation formula of the outside theoretical wheel speed is: ； wherein Vout represents the outer-side theoretical wheel speed.

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

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