Vehicle mass estimation method, system, device and medium based on distributed wheel hub motor drive

Abstract

The present invention discloses a method, system, device, and medium for estimating vehicle mass based on distributed in-wheel motor drive. The method includes: calculating the energy consumed by the in-wheel motor using the in-wheel motor output power, calculating the linear velocity of the wheel contact point using the wheel speed; calculating the change in wheel kinetic energy; calculating the energy consumed by the vehicle to overcome air resistance using the vehicle speed; subtracting the change in wheel kinetic energy and the energy consumed by the vehicle to overcome air resistance from the energy consumed by the in-wheel motor to obtain the residual energy of the in-wheel motor; calculating the change in kinetic energy per unit mass of the vehicle; using the ratio of the difference between the residual energy of the in-wheel motor at a current moment and the residual energy of the in-wheel motor at a previous moment to the difference between the change in kinetic energy per unit mass of the vehicle at a current moment and the change in kinetic energy per unit mass of the vehicle at a previous moment as a preliminary estimate of the vehicle mass at the previous moment, and performing median filtering on the preliminary estimates of the vehicle mass at all moments to obtain a final estimate of the vehicle mass. The present invention estimates a more accurate vehicle mass.

Description

Technical Field

[0001] The present invention relates to the fields of distributed front drive and vehicle mass estimation, and in particular to a vehicle mass estimation method, system, device and medium based on distributed wheel hub motor drive. Background Art

[0002] Existing vehicle mass estimation methods are generally based on vehicle longitudinal dynamics, using recursive least squares estimation with a forgetting factor for braking and acceleration conditions. These methods are primarily used for commercial vehicle mass estimation. The cargo mass of commercial vehicles significantly impacts the vehicle's mass, necessitating a more accurate estimation of the vehicle's mass as a control input for more precise vehicle control. In the passenger vehicle sector, passenger count is the primary factor driving vehicle mass variation. Passenger vehicle mass estimation can roughly estimate the vehicle's mass using the number of passengers and a presumed average weight. Summary of the Invention

[0003] The present invention addresses the deficiencies in the prior art and provides a method, system, device, and medium for estimating vehicle mass based on distributed in-wheel motor drive, thereby solving the problem of estimating vehicle mass when the vehicle travels a short distance.

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

[0005] A vehicle mass estimation method based on distributed in-wheel motor drive is applied to a vehicle driven by a distributed in-wheel motor, wherein the vehicle includes a vehicle controller, an in-wheel motor controller, an in-wheel motor, and wheels, and comprises the following steps:

[0006] Measure the wheel angle. Each time the wheel rotates through a fixed angle, record the wheel hub motor output power. Use the wheel hub motor output power to calculate the energy consumed by the wheel hub motor and the wheel speed. Use the wheel speed to calculate the linear velocity of the wheel contact point and the vehicle speed.

[0007] The change in wheel kinetic energy is calculated using the linear velocity of the wheel contact point;

[0008] Use vehicle speed to calculate the energy consumed by the vehicle to overcome air resistance;

[0009] The energy consumed by the hub motor is subtracted from the change in wheel kinetic energy and the energy consumed by the vehicle to overcome air resistance to obtain the residual energy of the hub motor.

[0010] Calculate the change in kinetic energy per unit mass of the vehicle;

[0011] The ratio of the difference between the current and previous wheel hub motor residual energy and the difference between the current and previous vehicle unit mass kinetic energy change is used as the preliminary estimate of the vehicle mass at the previous moment. The preliminary estimates of the vehicle mass at all moments are median filtered to obtain the final estimate of the vehicle mass.

[0012] To optimize the above technical solutions, specific measures taken also include:

[0013] Furthermore, the energy consumed by the hub motor is calculated by using the output power of the hub motor as follows:

[0014] Take the longest time T consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed angles θ n , output power P through 4 wheel hub motors 1n 、P 2n 、P 3n and P 4n The energy consumed by each hub motor is obtained by integrating the time t, and the formula is as follows:

[0015]

[0016] The total energy consumed by the four wheel hub motors is W mn =W 1n +W 2n +W 3n +W 4n ;

[0017] Where, P 1n It represents the output power of the first hub motor when the hub motor outer rotor rotates to the nth fixed angle, P 2n It represents the output power of the second hub motor when the hub motor outer rotor rotates to the nth fixed angle, P 3n It represents the output power of the third hub motor when the outer rotor of the hub motor rotates to the nth fixed angle, P 4n It represents the output power of the fourth hub motor when the hub motor outer rotor rotates to the nth fixed angle, T n-1 W represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. 1n Indicates the energy consumed by the first hub motor when the hub motor outer rotor rotates the nth fixed angle, W 2n Indicates the energy consumed by the second hub motor when the hub motor outer rotor rotates the nth fixed angle, W 3n Indicates the energy consumed by the third hub motor when the hub motor outer rotor rotates the nth fixed angle, W 4n It represents the energy consumed by the fourth hub motor when the outer rotor of the hub motor rotates the nth fixed angle.

[0018] Furthermore, the wheel speed is calculated as follows:

[0019] The speed n of wheel No. 1 each time it rotates through an angle θ 1n for The unit is r / min, the speed n of wheel No. 2 every time it rotates through an angle of θ 2n for The unit is r / min, the speed n of wheel No. 3 each time it rotates through an angle of θ 3n for The unit is r / min, the speed n of wheel No. 4 every time it rotates through an angle of θ 4n for The unit is r / min;

[0020] Where, t 1n It represents the time it takes for wheel No. 1 to rotate by an angle of θ, t 2n It represents the time it takes for wheel No. 2 to rotate by an angle of θ, t 3n It represents the time it takes for wheel No. 3 to rotate each time by an angle of θ, t 4n It represents the time for wheel No. 4 to rotate through an angle of θ each time; n represents the sequence number of the rotation angle θ;

[0021] The linear velocity of the wheel contact point calculated using the wheel speed is specifically:

[0022] Linear velocity v of the contact point of wheel No. 1 1n for Linear velocity v of the contact point of wheel No. 2 2n for Linear velocity v of the contact point of wheel No. 3 3n for Linear velocity v of the contact point of wheel No. 4 4n for Where R is the wheel radius;

[0023] The vehicle speed is calculated as follows: the linear speed of each wheel contact point is obtained, the maximum and minimum values ​​are discarded, and the remaining values ​​are averaged to obtain the vehicle speed v n .

[0024] Furthermore, the calculation of the wheel kinetic energy change using the linear velocity of the wheel contact point is specifically as follows:

[0025] Wheel No. 1 is in T n-1 to T n Change in kinetic energy within a time period v 1n Indicates that wheel No. 1 is at T n The linear velocity of the wheel contact point at the time v 1(n-1) Indicates that wheel No. 1 is at T n-1The linear velocity of the wheel contact point at the time T n-1 T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the maximum time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed rotation angles θ; J represents the moment of inertia of the wheel, and R is the wheel radius;

[0026] Wheel No. 2 is in T n-1 to T n Change in kinetic energy within a time period v 2n Indicates that wheel No. 2 is at T n The linear velocity of the wheel contact point at the time, v 2(n-1) Indicates that wheel No. 2 is at T n-1 The linear velocity of the wheel contact point at time ;

[0027] Wheel No. 3 is in T n-1 to T n Change in kinetic energy within a time period v 3n Indicates that wheel No. 3 is in T n The linear velocity of the wheel contact point at the time, v 3(n-1) Indicates that wheel No. 3 is in T n-1 The linear velocity of the wheel contact point at time ;

[0028] Wheel No. 4 is in T n-1 to T n Change in kinetic energy within a time period v 4n Indicates that wheel No. 4 is in T n The linear velocity of the wheel contact point at the time, v 4(n-1) Indicates that wheel No. 4 is in T n-1 The linear velocity of the wheel contact point at time ;

[0029] Total wheel kinetic energy change E (tire)n The calculation formula is as follows:

[0030] E (tire)n =E (tire)1n +E (tire)2n +E (tire)3n +E (tire)4n .

[0031] Furthermore, the energy consumed by the vehicle to overcome air resistance by using the vehicle speed is calculated as follows:

[0032] In T n-1 to T n The energy consumed by the vehicle to overcome air resistance during the time period E (aero)n for Where, T n-1T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n C represents the maximum time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed angles θ; d represents the air resistance coefficient of the car, A represents the frontal area of ​​the car, v n represents vehicle speed, and t represents time.

[0033] Furthermore, the energy consumed by the hub motor minus the change in wheel kinetic energy and the energy consumed by the vehicle to overcome air resistance is used to obtain the residual energy of the hub motor:

[0034] △E n =W mn -E (tire)n -E (aero)n

[0035] Where, ΔE n Indicates that in T n-1 to T n Remaining energy of the hub motor during the time period, W mn Indicates that in T n-1 to T n The total energy consumed by the four hub motors during the time period, E (tire)n Indicates that in T n-1 to T n Total wheel kinetic energy change during the time period, E (aero)n Indicates that in T n-1 to T n The energy consumed by the vehicle to overcome air resistance during the time period;

[0036] The calculation of the change in kinetic energy per unit mass of the vehicle is specifically as follows:

[0037]

[0038] Where, E kmn Indicates that in T n-1 to T n The change in kinetic energy per unit mass of the vehicle during the time period, v n Indicates T n The vehicle speed at the moment, v n-1 Indicates T n-1 The vehicle speed at the time, T n-1 T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n fixed rotation angles θ.

[0039] Furthermore, the calculation method of the preliminary estimated value of the vehicle mass at the previous moment is:

[0040]

[0041] Where m n-1 Represents the previous moment T n-1 Preliminary estimate of vehicle mass, ΔE n Indicates that in T n-1 to T n Remaining energy of the hub motor during the time period, ΔE (n-1) Indicates that in T n-2 to T n-1 The remaining energy of the hub motor during the time period, E kmn Indicates that in T n-1 to T n The change in kinetic energy per unit mass of the vehicle during the time period, E km(n-1) Indicates that in T n-2 to T n-1 The change in kinetic energy per unit mass of the vehicle during the time period, T n-1 T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n fixed rotation angles θ.

[0042] The present invention also proposes a vehicle mass estimation system based on distributed in-wheel motor drive, which is applied to a vehicle driven by a distributed in-wheel motor. The vehicle includes a vehicle controller, an in-wheel motor controller, an in-wheel motor, and wheels, including:

[0043] Encoder, built into the wheel hub motor, used to measure and record wheel angle;

[0044] Every time the wheel rotates a fixed angle, the hub motor controller records the hub motor output power.

[0045] The wheel hub motor controller sends the time signal and the wheel hub motor output power signal to the vehicle controller;

[0046] The vehicle controller includes: a computing unit, a preliminary estimation module and a filter;

[0047] The calculation unit is used to calculate the energy consumed by the hub motor using the output power of the hub motor; calculate the wheel speed; calculate the linear velocity of the wheel contact point using the wheel speed; calculate the vehicle speed; calculate the change in wheel kinetic energy using the linear velocity of the wheel contact point; calculate the energy consumed by the vehicle to overcome air resistance using the vehicle speed; subtract the change in wheel kinetic energy and the energy consumed by the vehicle to overcome air resistance from the energy consumed by the hub motor to obtain the residual energy of the hub motor; and calculate the change in kinetic energy per unit mass of the vehicle;

[0048] The preliminary estimation module is used to use the ratio of the difference between the current wheel hub motor residual energy and the previous wheel hub motor residual energy to the difference between the current vehicle unit mass kinetic energy change and the previous vehicle unit mass kinetic energy change as the preliminary estimation value of the vehicle mass at the previous moment.

[0049] The filter is used to perform median filtering on the preliminary estimated values ​​of the vehicle mass at all times to obtain the final estimated value of the vehicle mass.

[0050] The present invention also proposes an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the vehicle mass estimation method based on distributed hub motor drive as described above is implemented.

[0051] The present invention also provides a computer-readable storage medium storing a computer program, wherein the computer program enables a computer to execute the vehicle mass estimation method based on distributed hub motor drive as described above.

[0052] The beneficial effects of the present invention are as follows: the present invention solves the mass estimation problem when a vehicle travels a short distance, and can more accurately estimate the vehicle mass of a vehicle driven by a distributed hub motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a structural diagram of the vehicle mass estimation system based on distributed in-wheel motor drive of the present invention. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0055] Example 1

[0056] The present invention proposes a vehicle mass estimation method based on distributed in-wheel motor drive, which is applied to a vehicle driven by a distributed in-wheel motor. The vehicle includes a vehicle controller, an in-wheel motor controller, an in-wheel motor, and wheels. The method includes the following steps:

[0057] Measure the wheel angle, record the hub motor output power every time the wheel turns a fixed angle, and use the hub motor output power to calculate the energy consumed by the hub motor. Specifically:

[0058] Take the longest time T consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed angles θ n, output power P through 4 wheel hub motors 1n 、P 2n 、P 3n and P 4n The energy consumed by each hub motor is obtained by integrating the time t, and the formula is as follows:

[0059]

[0060] The total energy consumed by the four wheel hub motors is W mn =W 1n +W 2n +W 3n +W 4n ;

[0061] Where, P 1n It represents the output power of the first hub motor when the hub motor outer rotor rotates to the nth fixed angle, P 2n It represents the output power of the second hub motor when the hub motor outer rotor rotates to the nth fixed angle, P 3n It represents the output power of the third hub motor when the outer rotor of the hub motor rotates to the nth fixed angle, P 4n It represents the output power of the fourth hub motor when the hub motor outer rotor rotates to the nth fixed angle, T n-1 W represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. 1n Indicates the energy consumed by the first hub motor when the hub motor outer rotor rotates the nth fixed angle, W 2n Indicates the energy consumed by the second hub motor when the hub motor outer rotor rotates the nth fixed angle, W 3n Indicates the energy consumed by the third hub motor when the hub motor outer rotor rotates the nth fixed angle, W 4n It represents the energy consumed by the fourth hub motor when the outer rotor of the hub motor rotates the nth fixed angle.

[0062] Taking the longest time T1 consumed by the outer rotor of the hub motor in the four wheels to rotate an angle θ as an example, during time T1, the power output P through each hub motor is 11 、P 21 、P 31 、P 41 Calculate the energy consumed by each wheel hub motor That is, the energy consumed by the four wheel hub motors W m1 =W 11 +W 21 +W 31 +W 41 .

[0063] Calculate the wheel speed; specifically:

[0064] The speed n of wheel No. 1 each time it rotates through an angle θ 1n for The unit is r / min, the speed n of wheel No. 2 every time it rotates through an angle of θ 2n for The unit is r / min, the speed n of wheel No. 3 each time it rotates through an angle of θ 3n for The unit is r / min, the speed n of wheel No. 4 every time it rotates through an angle of θ 4n for The unit is r / min;

[0065] Where, t 1n It represents the time it takes for wheel No. 1 to rotate by an angle of θ, t 2n It represents the time it takes for wheel No. 2 to rotate by an angle of θ, t 3n It represents the time it takes for wheel No. 3 to rotate each time by an angle of θ, t 4n It represents the time for wheel No. 4 to rotate through an angle of θ each time; n represents the sequence number of the rotation angle θ.

[0066] The linear velocity of the wheel contact point is calculated using the wheel speed; specifically:

[0067] Linear velocity v of the contact point of wheel No. 1 1n for Linear velocity v of the contact point of wheel No. 2 2n for Linear velocity v of the contact point of wheel No. 3 3n for Linear velocity v of the contact point of wheel No. 4 4n for Where R is the wheel radius.

[0068] Calculate the vehicle speed; specifically: take the linear velocity of each wheel contact point, discard the maximum and minimum values, and average the remaining values ​​to obtain the vehicle speed v n .

[0069] The change in wheel kinetic energy is calculated using the linear velocity of the wheel contact point; specifically:

[0070] Wheel No. 1 is in T n-1 to T n Change in kinetic energy within a time period v 1n Indicates that wheel No. 1 is at T n The linear velocity of the wheel contact point at the time v 1(n-1) Indicates that wheel No. 1 is at T n-1 The linear velocity of the wheel contact point at the time T n-1T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the maximum time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed rotation angles θ; J represents the moment of inertia of the wheel, and R is the wheel radius;

[0071] Wheel No. 2 is in T n-1 to T n Change in kinetic energy within a time period v 2n Indicates that wheel No. 2 is at T n The linear velocity of the wheel contact point at the time, v 2(n-1) Indicates that wheel No. 2 is at T n-1 The linear velocity of the wheel contact point at time ;

[0072] Wheel No. 3 is in T n-1 to T n Change in kinetic energy within a time period v 3n Indicates that wheel No. 3 is in T n The linear velocity of the wheel contact point at the time, v 3(n-1) Indicates that wheel No. 3 is in T n-1 The linear velocity of the wheel contact point at time ;

[0073] Wheel No. 4 is in T n-1 to T n Change in kinetic energy within a time period v 4n Indicates that wheel No. 4 is in T n The linear velocity of the wheel contact point at the time, v 4(n-1) Indicates that wheel No. 4 is in T n-1 The linear velocity of the wheel contact point at time ;

[0074] Total wheel kinetic energy change E (tire)n The calculation formula is as follows:

[0075] E (tire)n =E (tire)1n +E (tire)2n +E (tire)3n +E (tire)4n .

[0076] Taking the longest time T1 consumed by the outer rotor of the hub motor in the four wheels to rotate an angle θ as an example, taking the linear velocity corresponding to each tire, the total wheel kinetic energy change E in the time period between the starting time and T1 can be obtained. (tire)1 =E (tire)1n +E (tire)2n +E (tire)3n +E (tire)4n The change in kinetic energy of wheel No. 1 between the start time and T1 v11 represents the linear velocity of wheel No. 1 at the contact point at T1, v 10 Indicates the linear velocity of the contact point of wheel No. 1 at the starting time, and the change in kinetic energy of wheel No. 2 between the starting time and T1. v 21 represents the linear velocity of wheel No. 2 at the contact point at T1, v 20 The linear velocity of the contact point of wheel No. 2 at the starting time, and the change in kinetic energy of wheel No. 3 between the starting time and T1 v 31 represents the linear velocity of wheel No. 3 at the contact point at T1, v 30 represents the linear velocity of the contact point of wheel No. 3 at the starting moment; the change in kinetic energy of wheel No. 4 between the starting moment and T1 v 41 represents the linear velocity of wheel No. 4 at the contact point at T1, v 40 represents the linear velocity of the contact point of wheel No. 4 at the starting moment; J represents the moment of inertia of the wheel.

[0077] The energy consumed by the vehicle to overcome air resistance is calculated using the vehicle speed; specifically:

[0078] In T n-1 to T n The energy consumed by the vehicle to overcome air resistance during the time period E (aero)n for Where, T n-1 T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n C represents the maximum time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed angles θ; d represents the air resistance coefficient of the car, A represents the frontal area of ​​the car, v n represents vehicle speed, and t represents time.

[0079] Taking the longest time T1 consumed by the outer rotor of the hub motor in the four wheels to rotate an angle θ as an example, during the vehicle driving time T1, the energy consumed by the vehicle to overcome the air resistance during the time T1 is calculated as v1 represents the vehicle speed at time T1.

[0080] The energy consumed by the hub motor is subtracted from the change in wheel kinetic energy and the energy consumed by the vehicle to overcome air resistance to obtain the residual energy of the hub motor. Specifically, it is:

[0081] ΔE n =W mn -E (tire)n -E (aero)n

[0082] Where, ΔE n Indicates that in T n-1 to T n Remaining energy of the hub motor during the time period, W mn Indicates that in T n-1 to T n The total energy consumed by the four hub motors during the time period, E (tire)n Indicates that in T n-1 to T n Total wheel kinetic energy change during the time period, E (aero)n Indicates that in T n-1 to T n The energy consumed by a vehicle to overcome air resistance during a period of time.

[0083] Calculate the change in kinetic energy per unit mass of the vehicle; specifically:

[0084]

[0085] Where, E kmn Indicates that in T n-1 to T n The change in kinetic energy per unit mass of the vehicle during the time period, v n Indicates T n The vehicle speed at the moment, v n-1 Indicates T n-1 The vehicle speed at the time, T n-1 T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n fixed rotation angles θ.

[0086] During time T1, the remaining energy after the hub motor overcomes the air resistance and changes the tire kinetic energy is ΔE1 = W m1 -E (tire)1 -E (aero)1 The change in kinetic energy per unit mass of the vehicle v1 is the vehicle speed at time T1, and v0 is the vehicle speed at the starting time.

[0087] The longest time consumed when the outer rotors of the hub motors of the four wheels rotate 2θ angles is T2. Similarly, the energy W consumed by the four hub motors during the period between time T1 and T2 can be calculated. m2 , tire kinetic energy change E (tire)2 , the energy consumed by the vehicle to overcome air resistance E (aero)2 The remaining energy after the hub motor overcomes the air resistance and changes the tire kinetic energy is ΔE2, and the kinetic energy change per unit mass of the vehicle is E km2 .

[0088] Vehicle driving time T1, T2, T3...T n The time interval is short and the vehicle travels a short distance. The energy consumed in overcoming the wheel rolling resistance due to the change in road and the change in gravitational potential energy caused by the change in slope are considered to be approximately equal.

[0089] The ratio of the difference between the current wheel hub motor residual energy and the previous wheel hub motor residual energy to the difference between the current vehicle unit mass kinetic energy change and the previous vehicle unit mass kinetic energy change is used as the preliminary estimate of the vehicle mass at the previous moment. The formula is as follows:

[0090]

[0091] Where m n-1 Represents the previous moment T n-1 Preliminary estimate of vehicle mass, ΔE n Indicates that in T n-1 to T n Remaining energy of the hub motor during the time period, ΔE (n-1) Indicates that in T n-2 to T n-1 The remaining energy of the hub motor during the time period, E kmn Indicates that in T n-1 to T n The change in kinetic energy per unit mass of the vehicle during the time period, E km(n-1) Indicates that in T n-2 to T n-1 The change in kinetic energy per unit mass of the vehicle during the time period, T n-2 T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-2 fixed angles θ. n-1 T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n fixed rotation angles θ.

[0092] The preliminary estimated values ​​of the vehicle mass at each moment are:

[0093] Perform median filtering on the preliminary estimated values ​​of the vehicle mass at all times to obtain the final estimated value of the vehicle mass.

[0094] Example 2

[0095] The present invention proposes a vehicle mass estimation system based on distributed hub motor drive corresponding to the method of embodiment 1, which is applied to a vehicle driven by a distributed hub motor, wherein the vehicle includes a vehicle controller, a hub motor controller, a hub motor and a wheel, such as Figure 1 As shown, including:

[0096] Encoder, built into the wheel hub motor, used to measure and record wheel angle;

[0097] Every time the wheel rotates a fixed angle, the hub motor controller records the hub motor output power.

[0098] The wheel hub motor controller sends the time signal and the wheel hub motor output power signal to the vehicle controller;

[0099] The vehicle controller includes: a computing unit, a preliminary estimation module and a filter;

[0100] The calculation unit is used to calculate the energy consumed by the hub motor using the output power of the hub motor; calculate the wheel speed; calculate the linear velocity of the wheel contact point using the wheel speed; calculate the vehicle speed; calculate the change in wheel kinetic energy using the linear velocity of the wheel contact point; calculate the energy consumed by the vehicle to overcome air resistance using the vehicle speed; subtract the change in wheel kinetic energy and the energy consumed by the vehicle to overcome air resistance from the energy consumed by the hub motor to obtain the residual energy of the hub motor; and calculate the change in kinetic energy per unit mass of the vehicle;

[0101] The preliminary estimation module is used to use the ratio of the difference between the current wheel hub motor residual energy and the previous wheel hub motor residual energy to the difference between the current vehicle unit mass kinetic energy change and the previous vehicle unit mass kinetic energy change as the current vehicle mass preliminary estimation value.

[0102] The filter is used to perform median filtering on the preliminary estimated values ​​of the vehicle mass at all times to obtain the final estimated value of the vehicle mass.

[0103] The implementation of each module and module function in the system is completely consistent with the steps of the method in Example 1, so it will not be repeated here.

[0104] Example 3

[0105] The present invention proposes an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for estimating vehicle mass based on distributed hub motor drive as described in Example 1 is implemented.

[0106] Example 4

[0107] The present invention provides a computer-readable storage medium storing a computer program, wherein the computer program enables a computer to execute the vehicle mass estimation method based on distributed in-wheel motor drive as described in the first embodiment.

[0108] In the embodiments disclosed herein, computer storage media can be tangible media that can contain or store programs for use by or in conjunction with an instruction execution system, device, or apparatus. Computer storage media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or equipment, or any suitable combination of the foregoing. More specific examples of computer storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROMs), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0109] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in this application can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0110] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A vehicle mass estimation method based on distributed in-wheel motor drive, applied to a vehicle driven by distributed in-wheel motors, wherein the vehicle comprises a vehicle controller, an in-wheel motor controller, an in-wheel motor, and wheels, characterized in that: The following steps are involved: Measure the wheel angle, record the wheel hub motor output power every time the wheel rotates a fixed angle, and use the wheel hub motor output power to calculate the energy consumed by the wheel hub motor; calculate the wheel speed, and use the wheel speed to calculate the linear speed of the wheel contact point; Calculate vehicle speed; The change in wheel kinetic energy is calculated using the linear velocity of the wheel contact point; Use vehicle speed to calculate the energy consumed by the vehicle to overcome air resistance; The energy consumed by the hub motor is subtracted from the change in wheel kinetic energy and the energy consumed by the vehicle to overcome air resistance to obtain the residual energy of the hub motor. Calculate the change in kinetic energy per unit mass of the vehicle; The ratio of the difference between the current and previous wheel hub motor residual energy and the difference between the current and previous vehicle unit mass kinetic energy change is used as the preliminary estimate of the vehicle mass at the previous moment. The preliminary estimates of the vehicle mass at all moments are median filtered to obtain the final estimate of the vehicle mass.

2. The vehicle mass estimation method based on distributed in-wheel motor drive according to claim 1, characterized in that: The energy consumed by the hub motor is calculated by using the output power of the hub motor as follows: Take the longest time T consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed angles θ n , output power P through 4 wheel hub motors 1n 、P 2n 、P 3n and P 4n The energy consumed by each hub motor is obtained by integrating the time t, and the formula is as follows: The total energy consumed by the four wheel hub motors is W mn =W 1n +W 2n +W 3n +W 4n ; Where, P 1n It represents the output power of the first hub motor when the hub motor outer rotor rotates to the nth fixed angle, P 2n It represents the output power of the second hub motor when the hub motor outer rotor rotates to the nth fixed angle, P 3n It represents the output power of the third hub motor when the outer rotor of the hub motor rotates to the nth fixed angle, P 4n It represents the output power of the fourth hub motor when the hub motor outer rotor rotates to the nth fixed angle, T n-1 W represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. 1n Indicates the energy consumed by the first hub motor when the hub motor outer rotor rotates the nth fixed angle, W 2n Indicates the energy consumed by the second hub motor when the hub motor outer rotor rotates the nth fixed angle, W 3n Indicates the energy consumed by the third hub motor when the hub motor outer rotor rotates the nth fixed angle, W 4n It represents the energy consumed by the fourth hub motor when the outer rotor of the hub motor rotates the nth fixed angle.

3. The vehicle mass estimation method based on distributed in-wheel motor drive according to claim 1, characterized in that: The wheel speed calculation is specifically as follows: The speed n of wheel No. 1 each time it rotates through an angle θ 1n for The unit is r / mi, the speed n of wheel No. 2 each time it rotates through an angle of θ 2n for The unit is r / mi, the speed n of wheel No. 3 each time it rotates through an angle of θ 3n for The unit is r / min, the speed n of wheel No. 4 every time it rotates through an angle of θ 4n for The unit is r / min; Where, t 1n It represents the time it takes for wheel No. 1 to rotate by an angle of θ, t 2n It represents the time it takes for wheel No. 2 to rotate by an angle of θ, t 3n It represents the time it takes for wheel No. 3 to rotate each time by an angle of θ, t 4n It represents the time for wheel No. 4 to rotate through an angle of θ each time; n represents the sequence number of the rotation angle θ; The linear velocity of the wheel contact point calculated using the wheel speed is specifically: Linear velocity v of the contact point of wheel No. 1 1n for Linear velocity v of the contact point of wheel No. 2 2n for Linear velocity v of the contact point of wheel No. 3 3n for Linear velocity v of the contact point of wheel No. 4 4n for Where R is the wheel radius; The vehicle speed is calculated as follows: the linear speed of each wheel contact point is obtained, the maximum and minimum values ​​are discarded, and the remaining values ​​are averaged to obtain the vehicle speed v n .

4. The vehicle mass estimation method based on distributed in-wheel motor drive according to claim 1, characterized in that: The calculation of the wheel kinetic energy change using the linear velocity of the wheel contact point is specifically as follows: Wheel No. 1 is in T n-1 to T n Change in kinetic energy within a time period v 1n Indicates that wheel No. 1 is at T n The linear velocity of the wheel contact point at the time v 1(n-1) Indicates that wheel No. 1 is at T n-1 The linear velocity of the wheel contact point at the time T n-1 T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the maximum time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed rotation angles θ; J represents the moment of inertia of the wheel, and R is the wheel radius; Wheel No. 2 is in T n-1 to T n Change in kinetic energy within a time period v 2n Indicates that wheel No. 2 is at T n The linear velocity of the wheel contact point at the time, v 2(n-1) Indicates that wheel No. 2 is at T n-1 The linear velocity of the wheel contact point at time ; Wheel No. 3 is in T n-1 to T n Change in kinetic energy within a time period v 3n Indicates that wheel No. 3 is in T n The linear velocity of the wheel contact point at the time, v 3(n-1) Indicates that wheel No. 3 is in T n-1 The linear velocity of the wheel contact point at time ; Wheel No. 4 is in T n-1 to T n Change in kinetic energy within a time period v 4n Indicates that wheel No. 4 is in T n The linear velocity of the wheel contact point at the time, v 4(n-1) Indicates that wheel No. 4 is in T n-1 The linear velocity of the wheel contact point at time ; Total wheel kinetic energy change E (tire)n The calculation formula is as follows: AND (tire)n =And (tire)1n +E (tire)2n +E (tire)3n +E (tire)4n 。 5. The vehicle mass estimation method based on distributed in-wheel motor drive according to claim 1, characterized in that: The energy consumed by the vehicle to overcome air resistance is calculated by using the vehicle speed as follows: In T n-1 to T n The energy consumed by the vehicle to overcome air resistance during the time period E (aero)n for Where, T n-1 T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n C represents the maximum time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed angles θ; d represents the air resistance coefficient of the car, A represents the frontal area of ​​the car, v n represents vehicle speed, and t represents time.

6. The vehicle mass estimation method based on distributed in-wheel motor drive according to claim 1, characterized in that: The energy consumed by the hub motor is subtracted from the change in wheel kinetic energy and the energy consumed by the vehicle to overcome air resistance to obtain the residual energy of the hub motor: ΔE n =W mn -E (tire)n -E (aero)n Where, ΔE n Indicates that in T n-1 to T n Remaining energy of the hub motor during the time period, W mn Indicates that in T n-1 to T n The total energy consumed by the four hub motors during the time period, E (tire)n Indicates that in T n-1 to T n Total wheel kinetic energy change during the time period, E (aero)n Indicates that in T n-1 to T n The energy consumed by the vehicle to overcome air resistance during the time period; The calculation of the change in kinetic energy per unit mass of the vehicle is specifically as follows: Where, E kmn Indicates that in T n-1 to T n The change in kinetic energy per unit mass of the vehicle during the time period, v n Indicates T n The vehicle speed at the moment, v n-1 Indicates T n-1 The vehicle speed at the time, T n-1 T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n fixed rotation angles θ.

7. The vehicle mass estimation method based on distributed in-wheel motor drive according to claim 1, characterized in that: The calculation method of the preliminary estimated value of the vehicle mass at the previous moment is: Where m n-1 Represents the previous moment T n-1 Preliminary estimate of vehicle mass, ΔE n Indicates that in T n-1 to T n Remaining energy of the hub motor during the time period, ΔE (n-1) Indicates that in T n-2 to T n-1 The remaining energy of the hub motor during the time period, E kmn Indicates that in T n-1 to T n The change in kinetic energy per unit mass of the vehicle during the time period, E km(n-1) Indicates that in T n-2 to T n-1 The change in kinetic energy per unit mass of the vehicle during the time period, T n-1 T represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the maximum time it takes for the outer rotor of the hub motor in the four wheels to rotate n fixed rotation angles θ.

8. A vehicle mass estimation system based on distributed in-wheel motor drive, applied to a vehicle driven by distributed in-wheel motors, the vehicle comprising a vehicle controller, an in-wheel motor controller, an in-wheel motor, and wheels, characterized in that: include: Encoder, built into the wheel hub motor, used to measure and record wheel angle; Every time the wheel rotates a fixed angle, the hub motor controller records the hub motor output power. The wheel hub motor controller sends the time signal and the wheel hub motor output power signal to the vehicle controller; The vehicle controller includes: a computing unit, a preliminary estimation module and a filter; The calculation unit is used to calculate the energy consumed by the hub motor using the output power of the hub motor; calculate the wheel speed; calculate the linear velocity of the wheel contact point using the wheel speed; calculate the vehicle speed; calculate the change in wheel kinetic energy using the linear velocity of the wheel contact point; calculate the energy consumed by the vehicle to overcome air resistance using the vehicle speed; subtract the change in wheel kinetic energy and the energy consumed by the vehicle to overcome air resistance from the energy consumed by the hub motor to obtain the remaining energy of the hub motor; calculate the change in kinetic energy per unit mass of the vehicle; the preliminary estimation module is used to use the ratio of the difference between the remaining energy of the hub motor at the current moment and the remaining energy of the hub motor at the previous moment to the difference between the change in kinetic energy per unit mass of the vehicle at the current moment and the change in kinetic energy per unit mass of the vehicle at the previous moment as the preliminary estimate of the vehicle mass at the previous moment, The filter is used to perform median filtering on the preliminary estimated values ​​of the vehicle mass at all times to obtain the final estimated value of the vehicle mass.

9. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for estimating vehicle mass based on distributed in-wheel motor drive according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: The computer program enables the computer to execute the vehicle mass estimation method based on distributed hub motor drive as described in any one of claims 1 to 7.

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