CN106184225A

CN106184225A - Longitudinal automobile speedestimate method that distributed type four-wheel-driven electrical vehicular power controls

Info

Publication number: CN106184225A
Application number: CN201610532772.9A
Authority: CN
Inventors: 张永生; 刘明辉; 杨兴旺; 魏文若; 李元
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2016-07-08
Filing date: 2016-07-08
Publication date: 2016-12-07
Anticipated expiration: 2036-07-08
Also published as: CN106184225B

Abstract

The invention discloses a longitudinal vehicle speed estimation method for dynamic control of a distributed four-wheel drive electric vehicle, which includes the following steps: S10, the vehicle reference vehicle speed rough estimation module estimates the free rolling wheel speed according to the motor speed and the wheel speed; Use the yaw rate and the steering wheel angle signal to convert the four free-rolling wheel speeds into the speed at the center of mass of the vehicle; use the speed at the center of mass of the vehicle to calculate the rough value of the vehicle reference speed; Dynamic pressure, motor speed or wheel speed, yaw rate and steering wheel angle signals estimate the rough value of vehicle body deceleration; S30, the Kalman filter module uses the steady-state Kalman filter to calculate the rough value of the reference vehicle speed in steps S10 and S20 Filter with the rough value of vehicle body deceleration, estimate and output the reference vehicle speed and vehicle body deceleration. The method for estimating the longitudinal vehicle speed for the dynamic control of the distributed four-wheel drive electric vehicle of the present invention has high real-time performance and precision.

Description

Longitudinal Velocity Estimation Method for Dynamic Control of Distributed Four-Wheel Electric Vehicle

技术领域technical field

本发明涉及一种新的分布式四驱电动车动力学控制的自适应纵向速度观测器，尤其涉及一种分布式四驱电动车动力学控制的纵向速度估算方法。The invention relates to a novel adaptive longitudinal velocity observer for dynamic control of distributed four-wheel drive electric vehicles, in particular to a longitudinal velocity estimation method for dynamic control of distributed four-wheel drive electric vehicles.

背景技术Background technique

在分布式四驱电动车动力学控制系统中，纵向车速的准确性与实时性直接影响整个动力学控制的最终效果。目前还没有一种能直接测量车辆纵向速度的简单，经济，适用而又可靠的方法。用GPS定位仪来测量汽车质心绝对速度，其实时性和准确性都不能满足控制的要求。用光学原理来测量汽车质心相对于路面的运动又对天气，道路状况，使用环境太敏感。因此，只能采用间接测量和数学模型相结合的方法来估算汽车纵向速度。近几年，许多学者提出了许多用于分布式动力学控制系统的车辆纵向速度的估算方法，从公开发表的文献来看，主要存在以下问题：估算方法过于理想化，难以实际应用；采用了复杂的估算方法，仅适合于仿真，难以在单片机上运行，不满足实时性要求；实时性达到要求，但估算精度又不足。In the distributed four-wheel drive electric vehicle dynamics control system, the accuracy and real-time performance of the longitudinal vehicle speed directly affect the final effect of the entire dynamics control. At present, there is no simple, economical, applicable and reliable method that can directly measure the longitudinal velocity of the vehicle. Using a GPS locator to measure the absolute speed of the car's center of mass cannot meet the requirements of control in terms of real-time and accuracy. Using optical principles to measure the movement of the car's center of mass relative to the road surface is too sensitive to weather, road conditions, and the use environment. Therefore, only the combination of indirect measurement and mathematical model can be used to estimate the vehicle longitudinal velocity. In recent years, many scholars have proposed many methods for estimating vehicle longitudinal velocity for distributed dynamics control systems. From the published literature, there are mainly the following problems: the estimation method is too idealized and difficult to apply in practice; Complicated estimation methods are only suitable for simulation, and are difficult to run on a single-chip microcomputer, which does not meet the real-time requirements; the real-time performance meets the requirements, but the estimation accuracy is insufficient.

因此有必要寻找一种既能够避开以上缺点又能较为准确、实时地估算车辆纵向速度的方法。Therefore, it is necessary to find a method that can not only avoid the above disadvantages but also estimate the longitudinal velocity of the vehicle more accurately and in real time.

发明内容Contents of the invention

本发明目的是提供一种用于分布式四驱电动车动力学控制的纵向车速估算方法，其针对上述现有技术中存在的缺陷，从实时性和准确性两方面入手，基于目前广泛应用的车用传感器而设计的。The purpose of the present invention is to provide a method for estimating longitudinal vehicle speed for dynamic control of distributed four-wheel drive electric vehicles, which aims at the defects in the above-mentioned prior art, starting from two aspects of real-time and accuracy, and based on the currently widely used Designed for automotive sensors.

本发明解决技术问题采用如下技术方案：一种用于分布式四驱电动车动力学控制的纵向车速估算方法，其包括以下步骤：The present invention solves the technical problem by adopting the following technical scheme: a method for estimating the longitudinal speed of a distributed four-wheel drive electric vehicle dynamics control, which includes the following steps:

S10、所述车辆参考车速粗略估算模块根据电机转速和轮速估算自由滚动轮速；利用横摆角速度和方向盘转角信号将4个自由滚动轮速转换为车辆质心处速度；利用车辆质心处速度计算车辆参考车速粗略值；S10. The vehicle reference speed rough estimation module estimates the free-rolling wheel speed according to the motor speed and wheel speed; converts the four free-rolling wheel speeds into the speed at the center of mass of the vehicle by using the yaw rate and the steering wheel angle signal; calculates the speed by using the speed at the center of mass of the vehicle rough value of vehicle reference speed;

S20、所述的车身减速粗略值估算模块利用电机扭矩、制动压力、电机转速或者轮速、横摆角速度和方向盘转角信号估算车身减速粗略值；S20. The vehicle body deceleration rough value estimating module uses motor torque, brake pressure, motor speed or wheel speed, yaw rate and steering wheel angle signals to estimate the vehicle body deceleration rough value;

S30、所述的卡尔曼滤波模块利用稳态卡尔曼滤波器对步骤S10和S20所计算的参考车速粗略值和车身减速粗略值进行滤波，估算并输出参考车速和车身减速度。S30. The Kalman filter module uses a steady-state Kalman filter to filter the rough reference vehicle speed and the rough vehicle deceleration value calculated in steps S10 and S20, and estimates and outputs the reference vehicle speed and vehicle deceleration.

可选的，采用下式计算自由滚动轮速v_free,i：Alternatively, the free-rolling wheel speed v _free ,i is calculated using the following formula:

${v v}_{f f r r e e e e,, i i} = = \frac{{v v}_{w w,, i i} \cdot &Center Dot; {C C}_{λ λ,, i i}}{{C C}_{λ λ,, i i} - - {μ μ}_{i i}} - - - - - - ((11))$

${C C}_{λ λ,, i i} = = \frac{{μ μ}_{i i}}{{λ λ}_{w w,, i i}} - - - - - - ((22))$

式中，v_w,i为轮速，C_λ,i为轮胎刚度，λ_w,i为车轮滑移率，μ_i附着系数，i＝1,2,3,4。In the formula, v _w,i is the wheel speed, C _λ,i is the tire stiffness, λ _w,i is the wheel slip rate, μ _i is the adhesion coefficient, i=1,2,3,4.

可选的，通过下式计算车辆质心处速度v_x,i，i＝1,2,3,4：Optionally, the velocity v _x,i at the center of mass of the vehicle is calculated by the following formula, i=1,2,3,4:

${v v}_{x x,, 11} = = \frac{{v v}_{f f r r e e e e,, 11} - - \overset{\cdot &Center Dot;}{ψ ψ} \cdot &Center Dot; {l l}_{a a} \cdot &Center Dot; {sinδ sinδ}_{f f}}{{cosδ cosδ}_{f f}} - - \overset{\cdot &Center Dot;}{ψ ψ} \cdot \cdot \frac{{t t}_{w w}}{22} - - {v v}_{y the y} \cdot &Center Dot; {tanδ tanδ}_{f f} - - - - - - ((33))$

${v v}_{x x,, 22} = = \frac{{v v}_{f f r r e e e e,, 22} - - \overset{\cdot &Center Dot;}{ψ ψ} \cdot &Center Dot; {l l}_{a a} \cdot &Center Dot; {sinδ sinδ}_{f f}}{{cosδ cosδ}_{f f}} - - \overset{\cdot \cdot}{ψ ψ} \cdot &Center Dot; \frac{{t t}_{w w}}{22} - - {v v}_{y the y} \cdot &Center Dot; {tanδ tanδ}_{f f} - - - - - - ((44))$

${v v}_{x x,, 33} = = {v v}_{f f r r e e e e,, 33} - - \overset{\cdot &Center Dot;}{ψ ψ} \cdot &Center Dot; \frac{{t t}_{w w}}{22} - - - - - - ((55))$

${v v}_{x x,, 44} = = {v v}_{f f r r e e e e,, 44} + + \overset{\cdot &Center Dot;}{ψ ψ} \cdot &Center Dot; \frac{{t t}_{w w}}{22} - - - - - - ((66))$

式中，为横摆角速度，δ_f为方向盘转角，t_w为轮距，l_a为质心到前轴距离，v_y为侧向车速。In the formula, is the yaw rate, δ _f is the steering wheel angle, t _w is the wheel base, l _a is the distance from the center of mass to the front axle, v _y is the lateral vehicle speed.

可选的，利用车辆质心处速度计算车辆参考车速粗略值v_{x_raw}通过下式实现：Optionally, using the speed at the center of mass of the vehicle to calculate the rough value v _{x_raw} of the vehicle reference speed is realized by the following formula:

${v v}_{x x__r r a a w w} = = {Σ Σ}_{i i = = 00}^{33} (({k k}_{i i} \cdot &Center Dot; {v v}_{x x,, i i})) / / {Σ Σ}_{i i = = 00}^{33} {k k}_{i i}$

式中，k_i为车轮稳定性因子。In the formula, _ki is the wheel stability factor.

可选的，所述车身减速粗略值可以采用下式计算：Optionally, the body deceleration rough value It can be calculated by the following formula:

${\overset{^^}{a a}}_{x x__r r a a w w} = = \frac{11}{m m} [[(({F f}_{x x,, 11} + + {F f}_{x x,, 22})) {cosδ cosδ}_{f f} + + {Δsinδ Δsinδ}_{f f} + + {F f}_{x x,, 33} + + {F f}_{x x,, 44} + + {F f}_{w w i i n no d d}]] - - - - - - ((88))$

${F f}_{x x,, i i} = = \frac{11}{{r r}_{w w,, i i}} [[\frac{{J J}_{w w,, i i}}{{r r}_{w w,, i i}} {{{a a}_{w w,, i i} + + {ζ ζ}_{11} (({v v}_{w w,, i i} - - {\overset{^^}{v v}}_{w w,, i i}))}} + + {T T}_{b b,, i i} - - {T T}_{d d,, i i}]] - - - - - - ((99))$

$Δ Δ = = \frac{- - (({F f}_{x x,, 11} + + {F f}_{x x,, 22})) \cdot &Center Dot; (({l l}_{a a} + + {l l}_{b b})) {sinδ sinδ}_{f f} + + (({F f}_{x x,, 11} - - {F f}_{x x,, 22})) \cdot &Center Dot; {cosδ cosδ}_{f f} \cdot &Center Dot; {l l}_{b b} + + (({F f}_{x x,, 33} - - {F f}_{x x,, 44})) \cdot &Center Dot; \frac{{t t}_{w w}}{22} - - {J J}_{z z} \cdot &Center Dot; \overset{\cdot\cdot \cdot\cdot}{ψ ψ} - - m m \cdot \cdot {\overset{\cdot &Center Dot;}{v v}}_{y the y} \cdot \cdot {l l}_{b b} - - m m \cdot &Center Dot; {v v}_{x x} \cdot \cdot \overset{\cdot \cdot}{ψ ψ} \cdot \cdot {l l}_{b b}}{(({l l}_{a a} + + {l l}_{b b})) \cdot \cdot {cosδ cosδ}_{f f}} - - - - - - ((1010))$

式中，m为整车质量；F_wind为风阻；F_x,i为车轮纵向力，i＝1,2,3,4；r_w,i为车轮半径；T_b,i为制动力；T_d,i为驱动力，J_z为车辆绕z轴的转动惯量，l_b为质心到后轴距离；J_w,i为车轮转动惯量，i＝1,2,3,4；a_w,i为车轮的加速度，i＝1,2,3,4；ζ₁为估算因子，通过查表法获得；为估算轮速，i＝1,2,3,4；为横摆角加速度；为侧向车加速度；v_x为车辆的前进方向的速度。In the formula, m is the mass of the vehicle; F _wind is the wind resistance; F _x,i is the wheel longitudinal force, i=1,2,3,4; r _w,i is the wheel radius; T _b,i is the braking force; T _d,i is the driving force, J _z is the moment of inertia of the vehicle around the z-axis, l _b is the distance from the center of mass to the rear axle; J _w,i is the moment of inertia of the wheel, i=1,2,3,4; a _w,i is the acceleration of the wheel, i=1, 2, 3, 4; ζ ₁ is the estimation factor, obtained by the look-up table method; For estimating wheel speed, i=1,2,3,4; is the yaw angular acceleration; is the lateral vehicle acceleration; v _x is the speed in the forward direction of the vehicle.

本发明具有如下有益效果：The present invention has following beneficial effects:

1.本发明设置有纵向车速估算系统，其包括电机扭矩、电机转速、轮速、制动压力、横摆角速度和方向盘转角信号、车辆参考车速粗略估算模块、车身减速粗略值估算模块和卡尔曼滤波模块；与现有技术相比，本发明所建立的分布式电动车动力学控制的纵向车速估算方法实时性好运算速度快，不但适用于分布式四驱电动车纵向车速的实时估算而且稍作修改后也适用于其他车辆的纵向车速估算。1. The present invention is provided with a longitudinal vehicle speed estimation system, which includes motor torque, motor speed, wheel speed, brake pressure, yaw rate and steering wheel angle signal, vehicle reference speed rough estimation module, vehicle body deceleration rough value estimation module and Kalman Filter module; Compared with the prior art, the method for estimating the longitudinal vehicle speed of the distributed electric vehicle dynamics control established by the present invention has good real-time performance and fast calculation speed, and is not only suitable for real-time estimation of the longitudinal vehicle speed of distributed four-wheel drive electric vehicles but also slightly It is also applicable to longitudinal speed estimation of other vehicles after modification.

2.本发明中的自由滚动轮速转换为车辆质心处速度的转换方式为本发明所特有，实际应用表明该转换能显著提高计算精度。2. The method of converting the free-rolling wheel speed into the speed at the center of mass of the vehicle in the present invention is unique to the present invention, and practical application shows that the conversion can significantly improve the calculation accuracy.

3.轮胎侧向力的准确估算是目前技术难点，本发明中的车身减速度粗略值估算公式利用了车轮纵向力来间接估算车轮侧向力，避免了轮胎侧向力的直接估算，提高了系统的计算精度。3. Accurate estimation of the tire lateral force is a technical difficulty at present. The vehicle body deceleration rough value estimation formula in the present invention utilizes the wheel longitudinal force to indirectly estimate the wheel lateral force, avoiding the direct estimation of the tire lateral force, and improving The calculation accuracy of the system.

附图说明Description of drawings

图1为本发明的纵向车速估算系统的结构示意图；Fig. 1 is the structural representation of longitudinal vehicle speed estimation system of the present invention;

具体实施方式detailed description

下面结合实施例及附图对本发明的技术方案作进一步阐述。The technical solutions of the present invention will be further elaborated below in conjunction with the embodiments and the accompanying drawings.

实施例1Example 1

本实施例提供了一种用于分布式四驱电动车动力学控制的纵向车速估算方法，其通过纵向车速估算系统实现，所述纵向车速估算系统包括：车辆参考车速粗略估算模块、车身减速粗略值估算模块和卡尔曼滤波模块；并包括以下步骤：This embodiment provides a longitudinal vehicle speed estimation method for dynamic control of distributed four-wheel drive electric vehicles, which is realized by a longitudinal vehicle speed estimation system. The longitudinal vehicle speed estimation system includes: a vehicle reference vehicle speed rough estimation module, a vehicle body deceleration rough Value estimation module and Kalman filter module; And comprise the following steps:

本实施例中，可以采用下式计算自由滚动轮速v_free,i：In this embodiment, the free rolling wheel speed v _free,i can be calculated using the following formula:

${v v}_{f f r r e e e e,, i i} = = \frac{{v v}_{w w,, i i} \cdot \cdot {C C}_{λ λ,, i i}}{{C C}_{λ λ,, i i} - - {μ μ}_{i i}} - - - - - - ((11))$

式中，v_w,i为轮速，其可由分布式电机的转速计算得到，即通过电机转速乘以减速器速比乘以车轮半径计算得到，C_λ,i为轮胎刚度，λ_w,i为车轮滑移率，μ_i附着系数，i＝1,2,3,4；当i为1时，表示左前轮；当i为2时，表示右前轮；当i为3时，表示左后轮；当i为4时，表示右后轮；下同。In the formula, v _w,i is the wheel speed, which can be calculated from the speed of the distributed motor, that is, it is calculated by multiplying the motor speed by the speed ratio of the reducer and multiplying the wheel radius, C _λ,i is the tire stiffness, λ _w,i is the wheel slip ratio, μ _i adhesion coefficient, i=1,2,3,4; when i is 1, it means the left front wheel; when i is 2, it means the right front wheel; when i is 3, it means The left rear wheel; when i is 4, it means the right rear wheel; the same below.

并且通过下式计算车辆质心处速度v_x,i，i＝1,2,3,4：And the velocity v _x,i at the center of mass of the vehicle is calculated by the following formula, i=1,2,3,4:

${v v}_{x x,, 11} = = \frac{{v v}_{f f r r e e e e,, 11} - - \overset{\cdot \cdot}{ψ ψ} \cdot \cdot {l l}_{a a} \cdot \cdot {sinδ sinδ}_{f f}}{{cosδ cosδ}_{f f}} - - \overset{\cdot &Center Dot;}{ψ ψ} \cdot &Center Dot; \frac{{t t}_{w w}}{22} - - {v v}_{y the y} \cdot &Center Dot; {tanδ tanδ}_{f f} - - - - - - ((33))$

${v v}_{x x,, 22} = = \frac{{v v}_{f f r r e e e e,, 22} - - \overset{\cdot \cdot}{ψ ψ} \cdot &Center Dot; {l l}_{a a} \cdot \cdot {sinδ sinδ}_{f f}}{{cosδ cosδ}_{f f}} - - \overset{\cdot &Center Dot;}{ψ ψ} \cdot &Center Dot; \frac{{t t}_{w w}}{22} - - {v v}_{y the y} \cdot \cdot {tanδ tanδ}_{f f} - - - - - - ((44))$

式中，为横摆角速度，δ_f为方向盘转角，t_w为轮距，l_a为质心到前轴距离，v_y为侧向车速；In the formula, is the yaw rate, δ _f is the steering wheel angle, t _w is the wheelbase, l _a is the distance from the center of mass to the front axle, v _y is the lateral vehicle speed;

本实施例中，利用车辆质心处速度计算车辆参考车速粗略值v_{x_raw}可以通过下式实现：In this embodiment, using the speed at the center of mass of the vehicle to calculate the rough value v _{x_raw} of the vehicle reference speed can be realized by the following formula:

S20、所述的车身减速粗略值估算模块利用电机扭矩、制动压力、电机转速或者轮速、横摆角速度和方向盘转角信号估算车身减速粗略值；S20. The vehicle body deceleration rough value estimation module uses motor torque, brake pressure, motor speed or wheel speed, yaw rate and steering wheel angle signals to estimate the vehicle body deceleration rough value;

本实施例中，所述车身减速粗略值可以采用下式计算：In this embodiment, the rough value of deceleration of the vehicle body It can be calculated by the following formula:

$Δ Δ = = \frac{- - (({F f}_{x x,, 11} + + {F f}_{x x,, 22})) \cdot &Center Dot; (({l l}_{a a} + + {l l}_{b b})) {sinδ sinδ}_{f f} + + (({F f}_{x x,, 11} - - {F f}_{x x,, 22})) \cdot &Center Dot; {cosδ cosδ}_{f f} \cdot &Center Dot; {l l}_{b b} + + (({F f}_{x x,, 33} - - {F f}_{x x,, 44})) \cdot &Center Dot; \frac{{t t}_{w w}}{22} - - {J J}_{z z} \cdot &Center Dot; \overset{\cdot\cdot \cdot\cdot}{ψ ψ} - - m m \cdot &Center Dot; {\overset{\cdot &Center Dot;}{v v}}_{y the y} \cdot &Center Dot; {l l}_{b b} - - m m \cdot &Center Dot; {v v}_{x x} \cdot \cdot \overset{\cdot \cdot}{ψ ψ} \cdot &Center Dot; {l l}_{b b}}{(({l l}_{a a} + + {l l}_{b b})) \cdot \cdot {cosδ cosδ}_{f f}} - - - - - - ((1010))$

S30、所述的卡尔曼滤波模块利用稳态卡尔曼滤波器对步骤S10和S20所计算的参考车速粗略值和车身减速粗略值进行滤波，估算并输出参考车速和车身减速度。S30. The Kalman filter module uses a steady-state Kalman filter to filter the rough reference vehicle speed and the rough deceleration value of the vehicle body calculated in steps S10 and S20, and estimates and outputs the reference vehicle speed and vehicle deceleration.

所述卡尔曼滤波可以通过下述迭代实现：The Kalman filter can be implemented through the following iterations:

${\overset{^^}{X x}}_{n no + + 11} = = ((Φ Φ - - {K K}_{f f} H h)) {\overset{^^}{X x}}_{n no} + + {K K}_{f f} {y the y}_{n no};;$

式中， In the formula,

以上实施例的先后顺序仅为便于描述，不代表实施例的优劣。The sequence of the above embodiments is only for convenience of description, and does not represent the advantages or disadvantages of the embodiments.

最后应说明的是：以上实施例仅用以说明本发明的技术方案，而非对其限制；尽管参照前述实施例对本发明进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本发明各实施例技术方案的精神和范围。Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. one kind for distributed type four-wheel-driven electrical vehicular power control longitudinal automobile speedestimate method, it is characterised in that include with Lower step:

S10, the described rough estimation block of vehicle reference speed freely roll wheel speed according to motor speed and wheel speed estimation；Utilize horizontal stroke Pivot angle speed and steering wheel angle signal freely roll wheel speed by 4 and are converted to speed at vehicle centroid；Utilize at vehicle centroid Speed calculation vehicle reference speed coarse value；

S20, described vehicle body deceleration coarse value estimation block utilize Motor torque, brake pressure, motor speed or wheel speed, horizontal stroke Pivot angle speed and steering wheel angle signal estimation vehicle body deceleration coarse value；

S30, described Kalman filtering module utilize the reference car that step S10 and S20 are calculated by steady-state Kalman filter Speed coarse value and vehicle body deceleration coarse value are filtered, and estimate and export reference speed and automobile body deceleration.

The longitudinal automobile speedestimate method controlled for distributed type four-wheel-driven electrical vehicular power the most according to claim 1, its It is characterised by, uses following formula to calculate and freely roll wheel speed v_free,i:

In formula, v_w,iFor wheel speed, C_λ,iFor tire stiffness, λ_w,iFor wheel slip, μ_iAttachment coefficient, i=1,2,3,4.

The longitudinal automobile speedestimate method controlled for distributed type four-wheel-driven electrical vehicular power the most according to claim 2, its It is characterised by, calculates speed v at vehicle centroid by following formula_x,i, i=1,2,3,4:

In formula,For yaw velocity, δ_fFor steering wheel angle, t_wFor wheelspan, l_aFor barycenter to front axle distance, v_yFor lateral car Speed.

The longitudinal automobile speedestimate method controlled for distributed type four-wheel-driven electrical vehicular power the most according to claim 3, its It is characterised by, utilizes speed calculation vehicle reference speed coarse value v at vehicle centroid_{x_raw}Realized by following formula:

In formula, k_iFor wheel stability sex factor.

The longitudinal automobile speedestimate method controlled for distributed type four-wheel-driven electrical vehicular power the most according to claim 4, its It is characterised by, described vehicle body deceleration coarse valueFollowing formula can be used to calculate:

In formula, m is complete vehicle quality；F_windFor windage；F_x,iFor wheel longitudinal force, i=1,2,3,4；r_w,iFor radius of wheel；T_b,iFor Brake force；T_d,iFor driving force, J_zFor vehicle around the rotary inertia of z-axis, l_bFor barycenter to rear axle distance；J_w,iIt is used to for vehicle wheel rotation Amount, i=1,2,3,4；a_w,iFor the acceleration of wheel, i=1,2,3,4；ζ₁For the estimation factor, obtained by look-up table；For estimating Calculation wheel speed, i=1,2,3,4；For yaw angle acceleration；For lateral car acceleration；v_xSpeed for the direction of advance of vehicle.