Complete vehicle mass estimation method, system and equipment based on distributed hub motor driving and medium

Abstract

The invention discloses a whole vehicle mass estimation method, system and device based on distributed hub motor driving and a medium. The method comprises the steps that energy consumed by a hub motor is calculated through the output power of the hub motor, and the linear speed of a wheel grounding point is calculated through the rotating speed of a wheel; calculating the wheel kinetic energy variation; calculating energy consumed by the vehicle to overcome the air resistance by using the vehicle speed; the wheel kinetic energy variation and the energy consumed by the vehicle for overcoming the air resistance are subtracted from the energy consumed by the hub motor to obtain the residual energy of the hub motor; calculating the kinetic energy variation of the unit mass of the vehicle; taking the ratio of the difference between the residual energy of the hub motor at the current moment and the residual energy of the hub motor at the previous moment to the difference between the kinetic energy variation of the unit mass of the vehicle at the current moment and the kinetic energy variation of the unit mass of the vehicle at the previous moment as a preliminary estimated value of the whole vehicle mass at the previous moment; and carrying out median filtering on the initial estimation values of the vehicle quality at all moments to obtain a final estimation value of the vehicle quality. The vehicle mass estimated by the method is more accurate.

Description

Technical Field

[0001] The present invention relates to the field 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 forgetting factors in braking and acceleration conditions, and are mostly used for commercial vehicle mass estimation. The mass of commercial vehicle cargo has a significant impact on the vehicle mass, and it is necessary to estimate the vehicle mass to obtain a more accurate vehicle mass as the control input to make vehicle control more precise. In the field of passenger vehicles, the number of passengers is the main reason for the change in vehicle mass. Passenger vehicle mass estimation can be roughly estimated by the number of passengers and the set per capita weight. Summary of the invention

[0003] The present invention aims at the deficiencies in the prior art and provides a method, system, device and medium for estimating the mass of a vehicle based on distributed wheel hub motor drive, so as to solve the mass estimation problem 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 wheel hub motor drive is applied to a vehicle driven by a distributed wheel hub motor, wherein the vehicle includes a vehicle controller, a wheel hub motor controller, a wheel hub motor and a wheel, and comprises the following steps:

[0006] Measure the wheel angle, record the hub motor output power every time the wheel turns a fixed angle, calculate the energy consumed by the hub motor using the hub motor output power, and calculate the wheel speed; calculate the linear speed of the wheel contact point using the wheel speed; calculate the vehicle speed;

[0007] The change of 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 residual energy of the hub motor at the current moment and the residual energy of the hub motor at the previous moment to the difference between the kinetic energy change per unit mass of the vehicle at the current moment and the kinetic energy change per unit mass of the vehicle at the previous moment is taken 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, the specific measures taken also include:

[0013] Furthermore, the energy consumed by the hub motor is calculated by using the hub motor output power 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 wheel 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 hub motor outer rotor 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 longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n-1 fixed angles θ. 1n It represents the energy consumed by the first hub motor when the outer rotor of the hub motor rotates to the nth fixed angle, W 2n It represents the energy consumed by the second hub motor when the hub motor outer rotor rotates the nth fixed angle, W 3n It represents 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 4th wheel hub motor when the outer rotor of the wheel hub motor rotates the nth fixed angle.

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

[0019] The speed n of wheel No. 1 every time it rotates through an angle of θ 1n for The unit is r / min. The speed n of wheel No. 2 every time it rotates an angle of θ 2n for The unit is r / min. The speed n of wheel No. 3 every 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] In the formula, t 1n It represents the time for wheel No. 1 to rotate each time by an angle of θ, t 2n It represents the time for wheel No. 2 to rotate each time by an angle of θ, t 3n It represents the time for wheel 3 to rotate each time by an angle of θ, t 4n represents the time for each rotation of the No. 4 wheel by an angle of θ; n represents the sequence number of the rotation angle θ;

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

[0022] Linear velocity v of the contact point of wheel No. 1 1n for The 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 specific method of calculating the vehicle speed is as follows: taking the linear speed of each wheel contact point, discarding the maximum and minimum values, and averaging the remaining values ​​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:

[0025] Wheel No. 1 is in T n-1 to T n Change in kinetic energy within a period of time 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 longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed 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 period of time 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 speed 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 period of time 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 speed of the wheel contact point at time ;

[0028] Wheel No. 4 in T n-1 to T n Change in kinetic energy within a period of time 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 speed 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 specifically 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 longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed angles θ; C 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 obtained 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 wheel 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] In the formula, 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 time, v n-1 Indicates T n-1 The vehicle speed at the time, T n-1 T represents the longest time consumed by 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.

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

[0040]

[0041] In the formula, 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 longest time consumed by 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.

[0042] The present invention also proposes a vehicle mass estimation system based on distributed wheel hub motor drive, which is applied to a vehicle driven by a distributed wheel hub motor. The vehicle includes a vehicle controller, a wheel hub motor controller, a wheel hub motor and a wheel, 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 speed of the wheel contact point using the wheel speed; calculate the vehicle speed; calculate the change in wheel kinetic energy using the linear speed 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;

[0048] The preliminary estimation module is used to use the ratio of the difference between the residual energy of the wheel hub motor at the current moment and the residual energy of the wheel hub motor at the previous moment and the difference between the kinetic energy change per unit mass of the vehicle at the current moment and the kinetic energy change per unit mass of the vehicle at the previous moment 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 proposes 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 wheel 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 the vehicle travels a short distance, and can more accurately estimate the vehicle mass of a vehicle driven by a distributed wheel hub motor. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0055] Embodiment 1

[0056] The present invention proposes a vehicle mass estimation method based on distributed wheel hub motor drive, which is applied to a vehicle driven by a distributed wheel hub motor. The vehicle includes a vehicle controller, a wheel hub motor controller, a wheel hub motor and a wheel, and 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 wheel 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 hub motor outer rotor 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 longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n-1 fixed angles θ. 1n It represents the energy consumed by the first hub motor when the hub motor outer rotor rotates the nth fixed angle, W 2n It represents the energy consumed by the second hub motor when the hub motor outer rotor rotates the nth fixed angle, W 3n It represents 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 4th wheel hub motor when the outer rotor of the wheel hub motor rotates the nth fixed angle.

[0062] Take 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 of 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 every time it rotates through an angle of θ 1n for The unit is r / min. The speed n of wheel No. 2 every time it rotates an angle of θ 2n for The unit is r / min. The speed n of wheel No. 3 every 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] In the formula, t 1n It represents the time for wheel No. 1 to rotate each time by an angle of θ, t 2n It represents the time for wheel No. 2 to rotate each time by an angle of θ, t 3n It represents the time for wheel 3 to rotate each time by an angle of θ, t 4n It indicates the time for wheel No. 4 to rotate by an angle of θ each time; n indicates 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 The 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 speed of each wheel contact point, discard the maximum and minimum values, and average the remaining values ​​to get 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 period of time 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 longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed 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 period of time 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 speed 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 period of time 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 speed of the wheel contact point at time ;

[0073] Wheel No. 4 in T n-1 to T n Change in kinetic energy within a period of time 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 speed 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, we can get the total wheel kinetic energy change E in the time period from the start time to T1. (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 It represents the linear speed of the wheel contact point of wheel No. 1 at the starting time, and the change in kinetic energy of wheel No. 2 during the period from the starting time to T1. v 21 represents the linear velocity of wheel No. 2 at the contact point at T1, v 20 It represents the linear speed of the wheel 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 wheel contact point of wheel No. 3 at the starting time; the change in kinetic energy of wheel No. 4 during the period from the starting time to 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 wheel contact point of wheel No. 4 at the starting moment; J represents the wheel rotational inertia.

[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 longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed angles θ; C 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, within the vehicle driving time T1, the energy consumed by the vehicle to overcome the air resistance within 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 remaining energy of the hub motor; specifically:

[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 wheel 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] In the formula, 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 time, v n-1 Indicates T n-1 The vehicle speed at the time, T n-1 T represents the longest time consumed by 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.

[0086] In time T1, the remaining energy after the wheel hub motor overcomes the air resistance and changes the tire kinetic energy is ΔE1 = W m1 -E (tire)1 -E (aero)1 . 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 wheel hub motor overcomes the air resistance and changes the kinetic energy of the tire 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, the vehicle travels a short distance, and 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] In the formula, 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 longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n-2 fixed rotation angles θ. n-1 T represents the longest time consumed by 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.

[0092] The preliminary estimate of the vehicle mass at each moment is:

[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] Embodiment 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 speed of the wheel contact point using the wheel speed; calculate the vehicle speed; calculate the change in wheel kinetic energy using the linear speed 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;

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

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

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

[0104] Embodiment 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 vehicle mass estimation method based on distributed hub motor drive as described in Example 1 is implemented.

[0106] Embodiment 4

[0107] The present invention proposes 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 in the first embodiment.

[0108] In the embodiments disclosed in the present application, the computer storage medium can be a tangible medium that can contain or store a program for use by or in conjunction with an instruction execution system, device or equipment. The computer storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the above. 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-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above.

[0109] Those of ordinary skill 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 only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A vehicle mass estimation method based on distributed wheel hub motor drive, applied to a vehicle driven by a distributed wheel hub motor, the vehicle comprising a vehicle controller, a wheel hub motor controller, a wheel hub motor and a wheel, characterized in that: The following steps are involved: Measure the wheel angle, record the wheel hub motor output power every time the wheel turns 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 of 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 residual energy of the hub motor at the current moment and the residual energy of the hub motor at the previous moment to the difference between the kinetic energy change per unit mass of the vehicle at the current moment and the kinetic energy change per unit mass of the vehicle at the previous moment is taken 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 wheel hub motor drive according to claim 1, characterized in that: The energy consumed by the hub motor is calculated by using the hub motor output power 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 wheel 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 hub motor outer rotor 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 longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. 1n It represents the energy consumed by the first hub motor when the hub motor outer rotor rotates the nth fixed angle, W 2n It represents the energy consumed by the second hub motor when the hub motor outer rotor rotates the nth fixed angle, W 3n It represents 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 4th wheel hub motor when the outer rotor of the wheel hub motor rotates the nth fixed angle.

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

4. The vehicle mass estimation method based on distributed wheel hub 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: Wheel No. 1 is in T n-1 to T n Change in kinetic energy within a period of time 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 speed of the wheel contact point at the time T n-1 T represents the longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed 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 period of time 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 speed of the wheel contact point at time ; Wheel No. 3 is in T n-1 to T n Change in kinetic energy within a period of time 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 speed of the wheel contact point at time ; Wheel No. 4 in T n-1 to T n Change in kinetic energy within a period of time 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 speed 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 wheel hub motor drive according to claim 1, characterized in that: The energy consumed by the vehicle to overcome air resistance by using the vehicle speed is specifically calculated 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 longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n-1 fixed rotation angles θ. n It represents the longest time consumed by the outer rotor of the hub motor in the four wheels to rotate n fixed angles θ; C 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 wheel hub motor drive according to claim 1, characterized in that: The energy consumed by the wheel 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 wheel 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 wheel 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: In the formula, 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 time, v n-1 Indicates T n-1 The vehicle speed at the time, T n-1 T represents the longest time consumed by 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.

7. The vehicle mass estimation method based on distributed wheel hub 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: In the formula, 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 longest time consumed by 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.

8. A vehicle mass estimation system based on distributed wheel hub motor drive, applied to a vehicle driven by a distributed wheel hub motor, the vehicle comprising a vehicle controller, a wheel hub motor controller, a wheel hub motor and a wheel, 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 speed of the wheel contact point using the wheel speed; calculate the vehicle speed; calculate the change in wheel kinetic energy using the linear speed 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; a preliminary estimation module is used to use the ratio of the difference between the remaining energy of the hub motor at a current moment and the remaining energy of the hub 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 a previous moment, The filter is used to median filter 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 the mass of a vehicle based on distributed hub motor drive as described in 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.

Images