Torque dynamic change control method, system and vehicle for multi-power source electric vehicle

Abstract

The present invention discloses a method, system and vehicle for controlling the dynamic change of torque of a multi-power source electric vehicle. The method comprises the following steps: determining the maximum total theoretical torque change of the whole vehicle based on the driving comfort requirement; determining the maximum target torque change of each motor within the task cycle; determining the first theoretical change of each motor torque within the task cycle; determining the total increase of motor torque, the total decrease of motor torque and the theoretical change of vehicle torque within the task cycle; determining the first proportional coefficient and the second proportional coefficient; setting the optimization parameters of the acceleration performance of the whole vehicle to determine the change of the target torque of each motor within the task cycle; obtaining the target torque of each motor after a task cycle; repeating the above steps until the target torque is the steady-state target torque after multiple task cycles. The method of the present invention combines the driving dynamics, comfort and safety of electric vehicles by regulating the motor torque, the whole vehicle torque and the whole vehicle impact.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric vehicle torque control, and more specifically, relates to a method, system and vehicle for controlling dynamic torque changes of a multi-power source electric vehicle. Background Art

[0002] Electric vehicles are an important development direction of the automobile industry. Electric vehicles have diversified power configurations. There are not only electric vehicles with single-bridge motor power configurations, but also dual-bridge motor configuration vehicles, as well as mxn configuration multi-motor hub or wheel-side motor electric vehicles such as 4x2, 4x4, 6x4 and other power configuration hub or wheel-side electric vehicles, as well as bridge motor + hub motor or hub motor configuration electric vehicles.

[0003] Since there are many motors in a multi-power source electric vehicle, the torque of each motor is constantly changing dynamically in the process of realizing driving intentions. If the total torque of the motor changes too much, it will cause a large impact on the vehicle and poor comfort for the driver and passengers; at the same time, the motor torque may change drastically, affecting the durability of the motor; if the total torque of the motor changes too little, the acceleration performance of the vehicle will be poor.

[0004] To solve the above problems, patent CN 102887080 A discloses a control method for rapid acceleration torque filtering of pure electric vehicles. Through the rapid acceleration system of pure electric vehicles, it can effectively avoid the excessive change of motor torque caused by the rapid acceleration of the vehicle and the change of motor torque when the motor torque is near zero torque, reduce the impact on the vehicle and improve driving comfort, but it does not consider the acceleration performance of the whole vehicle; patent CN 104842819 A discloses a control method and system for dynamic torque of electric vehicles, which selectively controls the speed of increase or decrease of torque by the torque change amount that changes with the accelerator pedal opening and the accelerator pedal change rate, so as to comprehensively consider power, comfort and safety. However, it only considers the torque controlled by the accelerator pedal, and does not consider the control of the torque of each motor, the situation where the motor torque changes drastically, and the protection of the motor's durability. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a method, system and vehicle for controlling the dynamic change of torque of a multi-power source electric vehicle, which integrates the driving power, comfort and safety of the electric vehicle by regulating the motor torque, vehicle torque and vehicle impact.

[0006] To achieve the above object, according to one aspect of the present invention, a method for controlling dynamic torque changes of a multi-power source electric vehicle is provided, comprising the following steps:

[0007] Step 1: Obtain the real-time mass of the vehicle and the maximum impact of the whole vehicle based on the driving comfort requirement, and determine the maximum total theoretical torque change of the whole vehicle based on the driving comfort requirement;

[0008] Step 2: Determine the maximum target torque change of each motor within the task cycle according to the steady-state target torque of each motor, the target torque at the previous moment and the torque change performance;

[0009] Step 3: Determine the first theoretical change in torque of each motor within the task cycle according to the maximum target torque change of each motor and the target torque of each motor at the current moment and the previous moment;

[0010] Step 4: Determine the total increase in motor torque, the total decrease in motor torque and the theoretical change in vehicle torque within the task cycle according to the first theoretical change in torque of each motor;

[0011] Step 5: Determine a first proportional coefficient and a second proportional coefficient according to the maximum total theoretical torque change of the vehicle, the total increase in motor torque, and the total decrease in motor torque;

[0012] Step 6: Set the acceleration performance optimization parameters of the whole vehicle, combine the first theoretical change of the torque of each motor, the first proportional coefficient and the second proportional coefficient, and determine the change of the target torque of each motor within the task cycle with the maximum total theoretical torque change of the whole vehicle and the maximum target torque change of each motor as constraints;

[0013] Step 7: Based on the change in the target torque of each motor during the task cycle and the target torque at the current moment, obtain the target torque of each motor after one task cycle; repeat the above steps until the target torque is a steady-state target torque after multiple task cycles.

[0014] Furthermore, the acquisition of the real-time mass of the vehicle includes: acquiring a dynamic equation of the vehicle at at least four vehicle speeds to obtain the real-time mass of the vehicle.

[0015] Furthermore, the real-time mass of the vehicle is:

[0016]

[0017] Among them, T k1 , T k2 , T k3 , T k4 -The actual driving torque output by the kth motor corresponding to the vehicle speed v1, v2, v3, v4;

[0018] i k -The reduction ratio of the rear end of the kth motor;

[0019] T x1 , T x2 , T x3, T x3 -The actual braking torque output by the xth brake caliper corresponding to the vehicle speed v1, v2, v3, v4;

[0020] m – the mass of the vehicle;

[0021] g - acceleration due to gravity;

[0022] θ1, θ2, θ3, θ4 - the slope of the road on which the vehicle is located when the vehicle speed is v1, v2, v3, v4;

[0023] f(v1), f(v2), f(v2), f(v3) - the corresponding air resistance of the vehicle when the speed is v1, v2, v3, v4;

[0024] a1, a2, a3, a4 - corresponding vehicle acceleration when the vehicle speed is v1, v2, v3, v4

[0025] v1, v2, v3, v4-vehicle speed, which can be obtained through wheel speed sensors;

[0026] n1-total number of motors in the vehicle;

[0027] n2 - total number of brake calipers on the vehicle.

[0028] Further, the maximum target torque variation of each motor within the task cycle is determined according to the steady-state target torque of each motor, the target torque at the previous moment, and the torque variation performance, including:

[0029] Determine the sign of the motor target torque change according to the steady-state target torque of each motor and the target torque at the previous moment;

[0030] According to the sign bit of the motor target torque change and the characteristic parameters of the motor torque change, the maximum target torque change of each motor within the task cycle is determined.

[0031] Furthermore, the first theoretical change of the torque of each motor is:

[0032] ΔT1 j =S j *min(ΔT maxj ,|T j -T(K-1) j |)

[0033] Among them, ΔT1 j -The first theoretical change in torque of the jth motor in the task cycle Δt; ΔT maxj -The upper limit of the torque allowed to change during the jth motor duty cycle Δt; T j -The j-th motor steady-state target torque calculated based on the throttle opening and the vehicle driving state; T(K-1)j -The target torque output by the jth motor at time K-1.

[0034] Further, the determination of the change in target torque of each motor during the task cycle includes:

[0035] If the absolute value of the theoretical change in the vehicle torque is not greater than the maximum total theoretical torque change of the vehicle, the change in the target torque of each motor during the task cycle is:

[0036] ΔT j =ΔT1 j *τ

[0037] Among them, τ-vehicle acceleration performance optimization parameter, τ∈(0,1]; ΔT1 j -The first theoretical change in torque of the jth motor in the task cycle Δt.

[0038] Furthermore, the step of determining the change in target torque of each motor during the task cycle further includes:

[0039] If the theoretical change of the vehicle torque is greater than the maximum total theoretical torque change of the vehicle, the change of the target torque of each motor during the task cycle is:

[0040]

[0041] Among them, ΔT1 j -The first theoretical change of the torque of the j-th motor in the task cycle Δt; τ-the vehicle acceleration performance optimization parameter, τ∈(0,1]; β1-the first proportional coefficient.

[0042] Furthermore, the step of determining the change in target torque of each motor during the task cycle further includes:

[0043] If the absolute value of the theoretical change in the vehicle torque is greater than the maximum total theoretical torque change of the vehicle, and the theoretical change in the vehicle torque is less than 0, then the change in the target torque of each motor during the task cycle is:

[0044]

[0045] Among them, ΔT1 j -The first theoretical change of the torque of the j-th motor in the task cycle Δt; τ-the vehicle acceleration performance optimization parameter, τ∈(0,1]; β2—the second proportional coefficient.

[0046] According to a second aspect of the present invention, there is provided an electric vehicle torque dynamic change control system, comprising:

[0047] The vehicle theoretical torque determination module is used to obtain the real-time mass of the vehicle and the maximum vehicle impact based on the driving comfort requirement, and determine the maximum total theoretical torque change of the vehicle based on the driving comfort requirement;

[0048] The motor maximum target torque change determination module is used to determine the maximum target torque change of each motor within the task cycle according to the target torque of each motor at the current moment and the previous moment and the torque change performance of each motor;

[0049] The first theoretical torque variation determination module is used to determine the maximum target torque variation of each motor within the task cycle according to the steady-state target torque of each motor, the target torque at the previous moment and the torque variation performance;

[0050] A total torque determination module, used to determine a total increase in motor torque, a total decrease in motor torque and a theoretical change in vehicle torque according to a first theoretical change in torque of each motor;

[0051] A proportional coefficient determination module, used to determine a first proportional coefficient and a second proportional coefficient according to a maximum total theoretical torque change of the vehicle, a total increase in motor torque, and a total decrease in motor torque;

[0052] A target torque variation determination module is used to determine the variation of the target torque of each motor within the task cycle based on the first theoretical variation of the torque of each motor, the vehicle acceleration performance optimization parameter, the first proportional coefficient and the second proportional coefficient, with the maximum total theoretical torque variation of the vehicle and the maximum target torque variation of each motor as constraints;

[0053] The steady-state target torque determination module is used to obtain the target torque of each motor after a task cycle based on the change in the target torque of each motor during the task cycle and the target torque at the current moment; repeat the above steps until the target torque after multiple task cycles is the steady-state target torque.

[0054] According to a third aspect of the present invention, there is provided a vehicle, comprising: a control system, wherein the control system is used to implement the method described.

[0055] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0056] 1. The control method of the present invention is widely applicable and can be applied to any number of multi-motor driven electric vehicles including dual-bridge motor vehicles, hub motor vehicles, hub motor vehicles, and any combination of these electric vehicles. By regulating the motor torque, vehicle torque and vehicle impact, the driving dynamics, comfort and safety of electric vehicles are integrated.

[0057] 2. The control method of the present invention avoids the drastic change of the motor torque, ensures that the actual torque change of the motor is within the torque change capacity, and improves the durability of the motor;

[0058] 3. The control method of the present invention ensures that the total torque change of the vehicle does not exceed the impact requirement of the vehicle, thereby improving the comfort of the vehicle. Meanwhile, during the torque change of multiple motors, some torques may increase and some torques may decrease. The present control method maximizes the use of the limiting requirements of the total torque change and can quickly realize the change of the torque of each motor.

[0059] 4. The control method of the present invention sets the vehicle acceleration performance optimization parameter τ, which can be calibrated according to the positioning requirements of the developed vehicle to change the vehicle's acceleration performance. At the same time, the parameter can also be used to monitor the driver's fierceness of the accelerator pedal operation to determine the value, so that even the same model can meet the different acceleration requirements of different drivers. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 This is a flow chart of a torque control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0062] like Figure 1 As shown, the present invention provides a method for controlling dynamic changes in torque of a multi-power source electric vehicle, comprising the following steps:

[0063] Step 1: Obtain the real-time mass of the vehicle and the maximum impact of the whole vehicle based on the driving comfort requirement, and determine the maximum total theoretical torque change of the whole vehicle based on the driving comfort requirement;

[0064] Step 2: Determine the maximum target torque change of each motor within the task cycle according to the steady-state target torque of each motor, the target torque at the previous moment and the torque change performance;

[0065] Step 3: Determine the first theoretical change in torque of each motor within the task cycle according to the maximum target torque change of each motor and the target torque of each motor at the current moment and the previous moment;

[0066] Step 4: Determine the total increase in motor torque, the total decrease in motor torque and the theoretical change in vehicle torque within the task cycle according to the first theoretical change in torque of each motor;

[0067] Step 5: Determine a first proportional coefficient and a second proportional coefficient according to the maximum total theoretical torque change of the vehicle, the total increase in motor torque, and the total decrease in motor torque;

[0068] Step 6: Set the acceleration performance optimization parameters of the whole vehicle, combine the first theoretical change of the torque of each motor, the first proportional coefficient and the second proportional coefficient, and determine the change of the target torque of each motor within the task cycle with the maximum total theoretical torque change of the whole vehicle and the maximum target torque change of each motor as constraints;

[0069] Step 7: Based on the change in the target torque of each motor during the task cycle and the target torque at the current moment, obtain the target torque of each motor after one task cycle; repeat the above steps until the target torque is a steady-state target torque after multiple task cycles.

[0070] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling dynamic changes in torque of a multi-power source electric vehicle, wherein the acquisition of the real-time mass of the vehicle includes: acquiring the dynamic equations of the vehicle at at least four vehicle speeds to obtain the real-time mass of the vehicle.

[0071] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling dynamic change of torque of a multi-power source electric vehicle, wherein the real-time mass of the vehicle is:

[0072]

[0073] Among them, T k1 , T k2 , T k3 , T k4 -The actual driving torque output by the kth motor corresponding to the vehicle speed v1, v2, v3, v4;

[0074] i k —Reduction ratio of the rear end of the kth motor;

[0075] T x1 , T x2 , T x3 , T x3 -The actual braking torque output by the xth brake caliper corresponding to the vehicle speed v1, v2, v3, v4;

[0076] m – the mass of the vehicle;

[0077] g - acceleration due to gravity;

[0078] θ1, θ2, θ3, θ4 - the slope of the road on which the vehicle is located when the vehicle speed is v1, v2, v3, v4;

[0079] f(v1), f(v2), f(v2), f(v3) - the corresponding air resistance of the vehicle when the speed is v1, v2, v3, v4;

[0080] a1, a2, a3, a4 - corresponding vehicle acceleration when the vehicle speed is v1, v2, v3, v4

[0081] v1, v2, v3, v4-vehicle speed, which can be obtained through wheel speed sensors;

[0082] n1-total number of motors in the vehicle;

[0083] n2 - total number of brake calipers on the vehicle.

[0084] Specifically, due to the number of people and goods loaded on the vehicle and the consumption of fuel during driving, the mass of the vehicle is not fixed but changes dynamically in real time. Therefore, it is necessary to use the vehicle dynamics principle to calculate the mass of the vehicle in real time. When the vehicle is driving, the dynamic equation state of the vehicle under four different speed conditions is obtained as follows:

[0085]

[0086] Where: T k1 , T k2 , T k3 , T k4 ——The actual driving torque output by the kth motor corresponding to the vehicle speed v1, v2, v3, v4; i k ——The reduction ratio of the rear end of the kth motor; T x1 , T x2 , T x3 , T x3 ——The actual braking torque output by the xth brake caliper when the vehicle speed is v1, v2, v3, v4; m——The mass of the vehicle; g——The acceleration due to gravity; θ1, θ2, θ3, θ4——The slope of the road on which the vehicle is located when the vehicle speed is v1, v2, v3, v4; f(v1), f(v2), f(v2), f(v3)——The air resistance of the whole vehicle when the vehicle speed is v1, v2, v3, v4; a1, a2, a3, a4——The acceleration of the whole vehicle when the vehicle speed is v1, v2, v3, v4; v1, v2, v3, v4——The vehicle speed, which can be obtained through the wheel speed sensor; n1——The total number of motors of the vehicle; n2——The total number of brake calipers of the vehicle.

[0087] Where: v1≠v2≠v3≠v4≠0

[0088] in:

[0089] Furthermore, if it is a bridge motor, i kis the reduction ratio of the subsequent reduction gearbox, which can also be a single-bridge motor model or a multi-bridge motor model; if it is a hub motor or wheel-side motor model, then i k It is the reduction ratio from the hub motor or wheel-side motor to the wheel.

[0090] Furthermore, according to the basic principles of automobile dynamics, f(v1), f(v2), f(v2), and f(v3) are quadratic functions, so let:

[0091] f(v)=γ1*v 2 +γ2*v+γ3

[0092] Among them: γ1, γ2, γ3 are the coefficients of air resistance, which are generally unknown.

[0093] Further, we know that:

[0094]

[0095] Furthermore, m is accurately calculated as:

[0096]

[0097] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling the dynamic change of torque of a multi-power source electric vehicle, wherein the maximum total theoretical torque change of the vehicle based on the driving comfort requirement is:

[0098] ΔT max =m*Δt*j0

[0099] Among them, m is the real-time mass of the vehicle; Δt is the task period of target torque change, generally 5ms is preferred; j0 is the maximum impact of the vehicle based on driving comfort requirements.

[0100] Specifically, there are:

[0101]

[0102] Where: j-vehicle impact, which is the derivative of the vehicle acceleration a. ΔT all -The total theoretical torque change of the vehicle. Δt-The task cycle of the target torque change, generally 5ms is preferred;

[0103] Furthermore, during driving, ΔT all It is equal to the sum of the changing torque of each motor divided by its corresponding transmission ratio, that is:

[0104] Where: ΔT j -The change in the target torque of the jth motor within the task cycle Δt, that is, the change in the motor target torque within each task cycle.j -Reduction ratio from the jth motor to the wheels.

[0105] Furthermore, in order to meet the requirements of driver and passenger comfort, the impact degree cannot be too large, otherwise it will lead to poor driver and passenger comfort, that is, it is necessary to satisfy |j|≤j0, and j0 is preferably 10m / s 3 ,but:

[0106] Furthermore, we know that: |ΔT all |≤m*Δt*j0

[0107] Furthermore, it can be known that: m*Δt*j0 is the upper limit of the total theoretical torque change of the vehicle ΔT max , that is: ΔT max =m*Δt*j0

[0108] Furthermore, it is necessary to meet the following requirements:

[0109] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling the dynamic change of torque of a multi-power source electric vehicle, wherein the maximum target torque change of each motor in a task cycle is determined according to the steady-state target torque of each motor and the target torque and torque change performance of the previous moment, including:

[0110] Determine the sign of the motor target torque change according to the steady-state target torque of each motor and the target torque at the previous moment;

[0111] According to the sign bit of the motor target torque change and the characteristic parameters of the motor torque change, the maximum target torque change of each motor within the task cycle is determined.

[0112] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling the dynamic change of torque of a multi-power source electric vehicle, wherein the sign bit of the target torque change of each motor is:

[0113]

[0114] Among them, S j -The sign of the change in target torque of the j-th motor within the time interval Δt; T j -The j-th motor steady-state target torque calculated based on the throttle opening and the vehicle driving state; T(K-1) j -The target torque output by the jth motor at time K-1.

[0115] Specifically, when the steady-state target torque of the motor is greater than the target torque at the previous moment, it means that a positive number needs to be added to the target torque at the previous moment to approach its target torque; when the steady-state target torque of the motor is less than the target torque at the previous moment, it means that a negative number needs to be added to the target torque at the previous moment to approach its target torque; when the steady-state target torque of the motor is equal to the target torque at the previous moment, it means that zero needs to be added to the target torque at the previous moment to equal its target torque.

[0116] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling the dynamic change of torque of a multi-power source electric vehicle, wherein the maximum target torque change of each motor in the task cycle is:

[0117]

[0118] Where, ΔT maxj -The upper limit of the torque variation allowed within the jth motor task cycle Δt; -The maximum value allowed for the torque increase of the jth motor within the time interval Δt1; -The maximum value allowed for the torque drop change of the jth motor within the time interval Δt1; It is the characteristic parameter of the motor, which is determined by the mechanical and electrical characteristics of the motor;

[0119] Specifically, for different electric vehicles, the motor models configured in the vehicle may be the same or different. Regardless of whether the motors are the same, the upper limit of the change in the target torque of each motor within the task cycle Δt should be calculated based on the ability of the motor torque to change.

[0120] The change of target torque of each motor within the task cycle Δt:

[0121]

[0122] in, -The maximum value allowed for the torque increase of the jth motor within the time interval Δt1; -The maximum value allowed for the torque drop change of the jth motor within the time interval Δt1; It is the characteristic parameter of the motor, which is a fixed value and is determined by the mechanical and electrical characteristics of the motor.

[0123] The maximum target torque change of each motor during the task cycle is:

[0124]

[0125] ΔT maxjThe maximum value of the torque change is calculated based on the ability of the motor to increase or decrease its torque during each motor task cycle. If it exceeds this value, it means that the motor is working beyond its capacity range, which reduces the durability of the motor. At the same time, the force change between the motor and the gears in the reduction box at the rear end is very drastic, which may cause damage to the motor.

[0126] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling the dynamic change of torque of a multi-power source electric vehicle, wherein the first theoretical change of the torque of each motor in the task cycle is:

[0127] ΔT1 j =S j *min(ΔT maxj ,|T j -T(K-1) j |)

[0128] Among them, ΔT1 j ——The first theoretical change of torque of the jth motor in the task cycle Δt; ΔT maxj is the maximum target torque change of each motor; S j -The sign of the change in target torque of the j-th motor within the time interval Δt; T j -The j-th motor steady-state target torque calculated based on the throttle opening and the vehicle driving state; T(K-1) j -The target torque output by the jth motor at time K-1.

[0129] Specifically, in order to protect the motor and achieve close-to-target torque changes for each motor in the vehicle, the first theoretical change in motor torque is the minimum of the upper limit of the jth motor torque allowed to change and the absolute value of the motor's steady-state target torque and its target torque at the previous moment.

[0130] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling the dynamic change of torque of a multi-power source electric vehicle, wherein the method for determining the change of the target torque of each motor in a task cycle includes:

[0131] If ||ΔT|≤ΔT max , then the change in target torque of each motor during the task cycle is:

[0132] ΔT j =ΔT1 j *τ

[0133] Among them, τ is the vehicle acceleration performance optimization parameter, τ∈(0,1].

[0134] Specifically, if ||ΔT|≤ΔT max ,Right now: That is, the change in target torque of each motor during the task cycle is based on the maximum total theoretical torque change of the vehicle required for driving comfort.

[0135] Specifically, τ is used to optimize the acceleration performance of the vehicle and can be set according to development requirements. τ can be calibrated as a fixed value by the developer, or the developer can set an initial value. During the actual use of the vehicle, the value is taken according to the rate of change of the accelerator pedal. The greater the rate of change of the accelerator pedal, the more the driver expects the vehicle's torque to change rapidly, and the greater the value of τ.

[0136] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling the dynamic change of torque of a multi-power source electric vehicle, wherein the setting method of τ is proportional to the throttle change rate:

[0137]

[0138] in, ——The average value of the rate of change of the throttle opening within a period of time; ρ-setting coefficient.

[0139] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling the dynamic change of torque of a multi-power source electric vehicle, wherein the total increase of the motor torque, the total decrease of the motor torque and the theoretical change of the vehicle torque are respectively:

[0140]

[0141] Where, ΔT zs -The theoretical sum of the motor torque increase, which is expressed as all ΔT1 greater than 0 j The sum of ΔT fs - The theoretical sum of the motor torque reduction, expressed as all ΔT1 less than 0 j The sum of ΔT-the theoretical sum of the vehicle torque change, which is expressed as all ΔT1 j The sum of .

[0142] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling dynamic change of torque of a multi-power source electric vehicle, wherein the first proportional coefficient β1 and the second proportional coefficient β2 are respectively:

[0143]

[0144] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling dynamic change of torque of a multi-power source electric vehicle, wherein the determination of the change amount of the target torque of each motor in the task cycle further includes:

[0145] If |ΔT|>ΔT max, and ΔT>0, then the change of the target torque of each motor during the task cycle is:

[0146]

[0147] Specifically, if |ΔT|>ΔT max , and ΔT>0, that is: available:

[0148]

[0149] Further, we know that:

[0150]

[0151] Further, we know that:

[0152]

[0153] Further, we know that:

[0154]

[0155] Further, we know that:

[0156]

[0157] Further, we know that: satisfying That is, the change in target torque of each motor during the task cycle is based on the maximum total theoretical torque change of the vehicle required for driving comfort.

[0158] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling dynamic change of torque of a multi-power source electric vehicle, wherein the determination of the change amount of the target torque of each motor in the task cycle further includes:

[0159] If |ΔT|>ΔT max , and ΔT<0, then the change of the target torque of each motor during the task cycle is:

[0160]

[0161] Specifically, if |ΔT|>ΔT max , and ΔT<0, then available:

[0162]

[0163] Further, we know that:

[0164]

[0165] Further, we know that:

[0166]

[0167] Further, we know that:

[0168]

[0169] Further, we know that:

[0170]

[0171] Therefore, satisfying That is, the change in target torque of each motor during the task cycle is based on the maximum total theoretical torque change of the vehicle required for driving comfort.

[0172] Based on the above embodiment, as an optional embodiment, the present invention provides a method for controlling the dynamic change of torque of a multi-power source electric vehicle, wherein the target torque of each motor after a task cycle is obtained based on the change in the target torque of each motor within the task cycle and the target torque at the current moment; the above steps are repeated until the target torque after multiple task cycles is a steady-state target torque, including:

[0173] Determine the target torque of each motor output at the next moment (i.e., a task cycle);

[0174] Taking the current moment as the new previous moment, determining the change in the target torque of each motor in the new task cycle, and determining the target torque output of each motor at the next moment (i.e., two task cycles);

[0175] The above process is repeated until the target torque after multiple task cycles is the steady-state target torque.

[0176] Specifically, the target torque output of each motor at the next moment (i.e., a task cycle) is determined:

[0177] T(K) j =T(K-1) j +ΔT j

[0178] Where: T(K) j ——The target torque output by the jth motor at time K; T(K-1) j and T(K) j The time interval between them is Δt, which is the task cycle;

[0179] (2) Take the current moment as the new previous moment and update f(K-1) j =T(K) j , and again determine the change in target torque of each motor in the new task cycle.

[0180] (3)T(K) j After several cycles, T(K) j =T j , to achieve the steady-state target torque of the vehicle, that is, the driving intention.

[0181] Based on the above embodiment, as an optional embodiment, the present invention provides an electric vehicle torque dynamic change control system, comprising:

[0182] The vehicle theoretical torque determination module is used to obtain the real-time mass of the vehicle and the maximum vehicle impact based on the driving comfort requirement, and determine the maximum total theoretical torque change of the vehicle based on the driving comfort requirement;

[0183] The motor maximum target torque change determination module is used to determine the maximum target torque change of each motor within the task cycle according to the target torque of each motor at the current moment and the previous moment and the torque change performance of each motor;

[0184] The first theoretical torque variation determination module is used to determine the maximum target torque variation of each motor within the task cycle according to the steady-state target torque of each motor, the target torque at the previous moment and the torque variation performance;

[0185] A total torque determination module, used to determine a total increase in motor torque, a total decrease in motor torque and a theoretical change in vehicle torque according to a first theoretical change in torque of each motor;

[0186] A proportional coefficient determination module, used to determine a first proportional coefficient and a second proportional coefficient according to a maximum total theoretical torque change of the vehicle, a total increase in motor torque, and a total decrease in motor torque;

[0187] A target torque variation determination module is used to determine the variation of the target torque of each motor within the task cycle based on the first theoretical variation of the torque of each motor, the vehicle acceleration performance optimization parameter, the first proportional coefficient and the second proportional coefficient, with the maximum total theoretical torque variation of the vehicle and the maximum target torque variation of each motor as constraints;

[0188] The steady-state target torque determination module is used to obtain the target torque of each motor after a task cycle based on the change in the target torque of each motor during the task cycle and the target torque at the current moment; repeat the above steps until the target torque after multiple task cycles is the steady-state target torque.

[0189] Based on the above embodiment, as an optional embodiment, the present invention provides a vehicle, including: a control system, wherein the control system is used to implement the above method.

[0190] The method of the embodiment of the present invention is implemented by relying on electronic devices, so it is necessary to introduce the relevant electronic devices. Based on this purpose, the embodiment of the present invention provides an electronic device, which includes: at least one central processor (Central processor), a communication interface (Communications Interface), at least one memory (Memory) and a communication bus, wherein at least one central processor, the communication interface, and at least one memory communicate with each other through the communication bus. At least one central processor can call the logic instructions in at least one memory to execute all or part of the steps of the method provided by the aforementioned various method embodiments.

[0191] In addition, the logic instructions in the at least one memory mentioned above can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each method embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0192] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0193] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0194] The flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to multiple embodiments of the present invention. Based on this understanding, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and sometimes in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of the boxes in the block diagram and / or the flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0195] In this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0196] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling dynamic torque changes of a multi-power source electric vehicle, characterized in that: The following steps are involved: Step 1: Obtain the real-time mass of the vehicle and the maximum impact of the whole vehicle based on the driving comfort requirement, and determine the maximum total theoretical torque change of the whole vehicle based on the driving comfort requirement; Step 2: Determine the maximum target torque change of each motor within the task cycle according to the steady-state target torque of each motor, the target torque at the previous moment and the torque change performance; Step 3: Determine the first theoretical change in torque of each motor within the task cycle according to the maximum target torque change of each motor and the target torque of each motor at the current moment and the previous moment; Step 4: Determine the total increase in motor torque, the total decrease in motor torque and the theoretical change in vehicle torque within the task cycle according to the first theoretical change in torque of each motor; Step 5: Determine a first proportional coefficient and a second proportional coefficient according to the maximum total theoretical torque change of the vehicle, the total increase in motor torque, and the total decrease in motor torque; Step 6: Set the acceleration performance optimization parameters of the whole vehicle, combine the first theoretical change of the torque of each motor, the first proportional coefficient and the second proportional coefficient, and determine the change of the target torque of each motor within the task cycle with the maximum total theoretical torque change of the whole vehicle and the maximum target torque change of each motor as constraints; Step 7: Based on the change in the target torque of each motor during the task cycle and the target torque at the current moment, obtain the target torque of each motor after one task cycle; repeat the above steps until the target torque is a steady-state target torque after multiple task cycles.

2. A method for controlling dynamic torque changes of a multi-power source electric vehicle according to claim 1, characterized in that: The acquisition of the real-time mass of the vehicle includes: acquiring a dynamic equation of the vehicle at at least four vehicle speeds to obtain the real-time mass of the vehicle.

3. The method for controlling dynamic torque changes of a multi-power source electric vehicle according to claim 1, characterized in that: The real-time mass of the vehicle is: Among them, T k1 , T k2 , T k3 , T k4 —The actual driving torque output by the kth motor corresponding to the vehicle speed v1, v2, v3, and v4; i k —Reduction ratio of the rear end of the kth motor; T x1 , T x2 , T x3 , T x3 —The actual braking torque output by the xth brake caliper corresponding to the vehicle speed v1, v2, v3, v4; m – the mass of the vehicle; g—acceleration due to gravity; θ1, θ2, θ3, θ4—the slope of the road on which the vehicle is located when the vehicle speed is v1, v2, v3, v4; f(v1), f(v2), f(v2), f(v3)—the corresponding air resistance of the vehicle when the vehicle speed is v1, v2, v3, v4; a1, a2, a3, a4—corresponding vehicle acceleration when the vehicle speed is v1, v2, v3, v4 v1, v2, v3, v4—vehicle speed, which can be obtained through wheel speed sensors; n1—the total number of motors in the vehicle; n2—Total number of brake calipers on the vehicle.

4. The method for controlling dynamic torque changes of a multi-power source electric vehicle according to claim 1, characterized in that: Determining the maximum target torque variation of each motor within the task cycle according to the steady-state target torque of each motor, the target torque at the previous moment, and the torque variation performance includes: Determine the sign of the motor target torque change according to the steady-state target torque of each motor and the target torque at the previous moment; According to the sign bit of the motor target torque change and the characteristic parameters of the motor torque change, the maximum target torque change of each motor within the task cycle is determined.

5. The method for controlling dynamic torque changes of a multi-power source electric vehicle according to claim 1, characterized in that: The first theoretical change in torque of each motor is: ΔT1 j =S j *min(ΔT maxj ,|T j -T(K-1) j |) Among them, ΔT1 j —The first theoretical change in torque of the jth motor in the task cycle Δt; ΔT maxj —The upper limit of the torque allowed to change in the jth motor task cycle Δt; T j —The j-th motor steady-state target torque calculated based on the throttle opening and the vehicle driving state; T(K-1) j —The target torque output by the jth motor at time K-1; S j —The sign of the change in target torque of the jth motor within the time interval Δt.

6. The method for controlling dynamic torque changes of a multi-power source electric vehicle according to claim 1, characterized in that: Determining the change in target torque of each motor during the task cycle includes: If the absolute value of the theoretical change in the vehicle torque is not greater than the maximum total theoretical torque change of the vehicle, the change in the target torque of each motor during the task cycle is: ΔT j =ΔT1 j *t Among them, τ is the vehicle acceleration performance optimization parameter, τ∈(0,1]; ΔT1 j —The first theoretical change in torque of the jth motor in the task cycle Δt; If the theoretical change of the vehicle torque is greater than the maximum total theoretical torque change of the vehicle, the change of the target torque of each motor during the task cycle is: Among them, ΔT1 j —The first theoretical change of the torque of the j-th motor in the task cycle Δt; τ—the optimization parameter of the vehicle acceleration performance, τ∈(0,1]; β1—the first proportional coefficient; If the absolute value of the theoretical change in the vehicle torque is greater than the maximum total theoretical torque change of the vehicle, and the theoretical change in the vehicle torque is less than 0, the change in the target torque of each motor during the task cycle is: Among them, ΔT1 j —The first theoretical change of the torque of the j-th motor in the task cycle Δt; τ—the vehicle acceleration performance optimization parameter, τ∈(0,1]; β2—the second proportional coefficient.

7. The method for controlling dynamic torque changes of a multi-power source electric vehicle according to claim 1, characterized in that: The total increase in motor torque, the total decrease in motor torque and the theoretical change in vehicle torque are respectively: Where, ΔT zs —The theoretical sum of the motor torque increase; ΔT fs —Theoretical sum of motor torque reduction; ΔT—Theoretical sum of vehicle torque change; ΔT1 j —The first theoretical change of the torque of the jth motor in the task cycle Δt; i j —reduction ratio from the jth motor to the wheel; S j —The sign of the change in target torque of the jth motor within the time interval Δt.

8. The method for controlling dynamic torque changes of a multi-power source electric vehicle according to claim 1, characterized in that: The first proportional coefficient and the second proportional coefficient are respectively: Among them, β1 is the first proportional coefficient; β2 is the second proportional coefficient; ΔT zs —The theoretical sum of the motor torque increase; ΔT fs —Theoretical sum of motor torque reduction; ΔT max -The maximum total theoretical torque change of the vehicle based on driving comfort requirements.

9. A torque dynamic change control system for an electric vehicle, characterized in that: include: The vehicle theoretical torque determination module is used to obtain the real-time mass of the vehicle and the maximum vehicle impact based on the driving comfort requirement, and determine the maximum total theoretical torque change of the vehicle based on the driving comfort requirement; The motor maximum target torque change determination module is used to determine the maximum target torque change of each motor within the task cycle according to the target torque of each motor at the current moment and the previous moment and the torque change performance of each motor; The first theoretical torque variation determination module is used to determine the maximum target torque variation of each motor within the task cycle according to the steady-state target torque of each motor, the target torque at the previous moment and the torque variation performance; A total torque determination module, used to determine a total increase in motor torque, a total decrease in motor torque and a theoretical change in vehicle torque according to a first theoretical change in torque of each motor; A proportional coefficient determination module, used to determine a first proportional coefficient and a second proportional coefficient according to a maximum total theoretical torque change of the vehicle, a total increase in motor torque, and a total decrease in motor torque; A target torque variation determination module is used to determine the variation of the target torque of each motor within the task cycle based on the first theoretical variation of the torque of each motor, the vehicle acceleration performance optimization parameter, the first proportional coefficient and the second proportional coefficient, with the maximum total theoretical torque variation of the vehicle and the maximum target torque variation of each motor as constraints; The steady-state target torque determination module is used to obtain the target torque of each motor after a task cycle based on the change in the target torque of each motor during the task cycle and the target torque at the current moment; repeat the above steps until the target torque after multiple task cycles is the steady-state target torque.

10. A vehicle, characterized in that: include: A control system, wherein the control system is used to implement the method according to any one of claims 1 to 8.

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