阅读说明：本技术 坡度检测方法、系统及车辆 (Slope detection method, system and vehicle ) 是由 牛小锋 孙玉 周申光 张英富 刘自敏 刘天培 曾迁 于 2018-05-23 设计创作，主要内容包括：本发明提供了一种坡度检测方法、系统及车辆。其中,坡度检测方法,包括：获取车辆状态信号,其中,车辆状态信号包括第一车辆状态信号和根据第一车辆状态信号得到的第二车辆状态信号,第一车辆状态信号包括纵向加速度信号；根据车辆状态信号得到坡道预测信号和车辆稳定状态信号；根据坡道预测信号和车辆稳定状态信号判断车辆是否行驶在坡道上；如果是,则对纵向加速度信号进行滤波,并根据滤波结果和纵向加速度信号确定坡道的坡度值。本发明的方法无需增加额外的硬件,便可以简单方便且准确地计算出道路的坡度值,具有运算简单且成本低的优点。(The present invention provides a kind of slope detection method, system and vehicles.Wherein, slope detection method, comprising: obtain Vehicular status signal, wherein Vehicular status signal includes the first Vehicular status signal and the second Vehicular status signal for being obtained according to the first Vehicular status signal, and the first Vehicular status signal includes longitudinal acceleration signal；Ramp prediction signal and vehicle stabilization status signal are obtained according to Vehicular status signal；Judge whether vehicle travels on ramp according to ramp prediction signal and vehicle stabilization status signal；If it is, being filtered to longitudinal acceleration signal, and the value of slope in ramp is determined according to filter result and longitudinal acceleration signal.Method of the invention without increasing additional hardware, can value of slope simple and convenient and that road is accurately calculated, have the advantages that operation is simple and at low cost.)

1. a kind of slope detection method, which comprises the following steps:

Obtain Vehicular status signal, wherein the Vehicular status signal is including the first Vehicular status signal and according to described first The second Vehicular status signal that Vehicular status signal obtains, first Vehicular status signal includes longitudinal acceleration signal；

Ramp prediction signal and vehicle stabilization status signal are obtained according to the Vehicular status signal；

Judge whether vehicle travels on ramp according to the ramp prediction signal and the vehicle stabilization status signal；

If it is, being filtered to the longitudinal acceleration signal, and according to filter result and the longitudinal acceleration signal Determine the value of slope in ramp.

2. slope detection method according to claim 1, which is characterized in that first Vehicular status signal further include: Wheel speed signal, yaw rate signal, master cylinder pressure signal, ABS activation signal, TCS activation signal and VDC activation signal, institute Stating the second Vehicular status signal includes: wheel speed acceleration signal, acceleration error signal and yaw velocity derivative signal,

Wherein, the yaw velocity derivative signal is obtained by the yaw rate signal derivation, the wheel speed acceleration letter It number is obtained by the wheel speed signal derivation, the acceleration error signal is accelerated by the longitudinal acceleration signal and the wheel speed Degree signal is calculated, the calculation formula are as follows:

AccelError=MAX [abs (AccelError-WhlVxLF_isg), abs (AccelError-WhlVxLR_isg), Abs (AccelError-WhlVxRF_isg), abs (AccelError-WhlVxRR_isg)],

Wherein, the AccelError is acceleration error signal, and the WhlVxLF_isg is left front wheel speed signal, described After WhlVxRF_isg is off-front wheel speed signal, the WhlVxLR_isg is left back wheel speed signal, the WhlVxRR_isg is the right side Wheel speed signal.

3. slope detection method according to claim 2, which is characterized in that

When the vehicle be two drive when, the ramp prediction signal is obtained by following formula, the formula are as follows:

GradeEstimation=VehlonAccel-SUM (Driven WheelLongAccel)/2,

When the vehicle is four-wheel drive cars, the ramp prediction signal is obtained by following formula, the formula are as follows:

GradeEstimation=VehlonAccel-SUM (WheelLongAccel)/4,

Wherein, the GradeEstimation is ramp prediction signal, and the VehlonAccel is longitudinal acceleration letter Number, the WheelLongAccel wheel speed acceleration signal.

4. slope detection method according to claim 2, which is characterized in that described to obtain vehicle according to Vehicular status signal Steady state signal, comprising:

Judge acceleration error signal whether less than the first threshold value；

If it is not, then the vehicle stabilization status signal is invalid；

If it is, further judging yaw velocity whether less than the second threshold value, if it is not, then the vehicle stabilization state Invalidating signal；

If it is, further judging whether the yaw velocity derivative signal is less than third threshold value；

If it is not, then the vehicle stabilization status signal is invalid；

If it is, further judging the master cylinder pressure signal whether less than the 4th threshold value；

If it is not, then the vehicle stabilization status signal is invalid；

If it is, further judging ABS activation signal, TCS activation signal and VDC activation signal whether effectively；

If it is, the vehicle stabilization status signal is invalid, otherwise the vehicle stabilization status signal is effective.

5. slope detection method according to claim 2, which is characterized in that described according to ramp prediction signal and the vehicle Steady state signal judges whether vehicle travels on ramp, comprising:

Judge whether the absolute value of ramp prediction signal is greater than critical value；

If it is not, then further judging whether vehicle stabilization status signal is effective；

If it is, further judging whether the duration is greater than the crash time；

If it is being then to determine that vehicle does not travel on ramp；

If the absolute value of ramp prediction signal is greater than critical value, further judge whether vehicle stabilization status signal is effective；

If it is, further judging whether the duration is greater than the crash time；

If it is, determining vehicle driving on ramp.

6. slope detection method according to claim 2, which is characterized in that described to be filtered to longitudinal acceleration signal Wave, and determine according to filter result and the longitudinal acceleration signal value of slope in ramp, comprising:

The longitudinal acceleration signal is filtered by following formula, obtains the noise and interference letter of the longitudinal acceleration Number, wherein the formula are as follows:

Wherein, u is input signal, and T is execution cycle, and m is the variable of adjustable cutoff frequency；

The value of slope in the ramp is obtained according to the longitudinal acceleration signal and the noise and interference signal.

7. a kind of slope detection system characterized by comprising

Signal processing module, for obtaining Vehicular status signal, wherein the Vehicular status signal is believed including the first vehicle-state Number and according to the second Vehicular status signal that first Vehicular status signal obtains, first Vehicular status signal includes vertical To acceleration signal；

Ramp prediction module, for obtaining ramp prediction signal according to the Vehicular status signal；

Vehicle stable state judgment module, for obtaining vehicle stabilization status signal according to the Vehicular status signal；

Ramp index module, for judging whether vehicle goes according to the ramp prediction signal and the vehicle stabilization status signal It sails on ramp；

Ramp is worth compensating module, travels when on ramp for being in vehicle, is filtered to the longitudinal acceleration signal, And the value of slope in ramp is determined according to filter result and the longitudinal acceleration signal.

8. slope detection system according to claim 1, which is characterized in that first Vehicular status signal further include: Wheel speed signal, yaw rate signal, master cylinder pressure signal, ABS activation signal, TCS activation signal and VDC activation signal, institute Stating the second Vehicular status signal includes: wheel speed acceleration signal, acceleration error signal and yaw velocity derivative signal,

Wherein, the yaw velocity derivative signal is obtained by the yaw rate signal derivation, the wheel speed acceleration letter It number is obtained by the wheel speed signal derivation, the acceleration error signal is accelerated by the longitudinal acceleration signal and the wheel speed Degree signal is calculated, the calculation formula are as follows:

AccelError=MAX [abs (AccelError-WhlVxLF_isg), abs (AccelError-WhlVxLR_isg), Abs (AccelError-WhlVxRF_isg), abs (AccelError-WhlVxRR_isg)],

Wherein, the AccelError is acceleration error signal, and the WhlVxLF_isg is left front wheel speed signal, described After WhlVxRF_isg is off-front wheel speed signal, the WhlVxLR_isg is left back wheel speed signal, the WhlVxRR_isg is the right side Wheel speed signal.

9. slope detection system according to claim 8, which is characterized in that the vehicle stable state judgment module is used In:

Judge acceleration error signal whether less than the first threshold value；

If it is not, then the vehicle stabilization status signal is invalid；

If it is, further judging yaw velocity whether less than the second threshold value, if it is not, then the vehicle stabilization state Invalidating signal；

If it is, further judging whether the yaw velocity derivative signal is less than third threshold value；

If it is not, then the vehicle stabilization status signal is invalid；

If it is, further judging the master cylinder pressure signal whether less than the 4th threshold value；

If it is not, then the vehicle stabilization status signal is invalid；

If it is, further judging ABS activation signal, TCS activation signal and VDC activation signal whether effectively；

If it is, the vehicle stabilization status signal is invalid, otherwise the vehicle stabilization status signal is effective.

10. a kind of vehicle, which is characterized in that be arranged just like the described in any item slope detection systems of claim 7-9.

Technical field

The present invention relates to automobile technical field, in particular to a kind of slope detection method, system and vehicle.

Background technique

An important factor for vehicle ride comfort and comfort are influenced when the type of road and the situation on road surface are vehicle drivings One of, sometimes it be also one of activation or Rule of judgment for closing certain electric-control systems (such as: being detected in automobile longitudinal descending To the gradient it is larger after, it is automatic to activate the slow drop function in abrupt slope).If can accurately and timely detect that the type of road will be more square Just developer formulates different control strategies for different information of road surface and different control systems in the stage of designing and developing And then promote the quality of vehicle.Wherein, there are two types of the operating condition that vehicle travels on longitudinal ramp road surface is usual: one is longitudinal slopes Road goes up a slope, and one is in longitudinal ramp descending.

Summary of the invention

In view of this, the present invention is directed to propose a kind of slope detection method.The slope detection method is without increasing additionally Hardware, can value of slope simple and convenient and that road is accurately calculated, have the advantages that operation is simple and at low cost.

In order to achieve the above objectives, the technical scheme of the present invention is realized as follows:

A kind of slope detection method, comprising the following steps: obtain Vehicular status signal, wherein the Vehicular status signal Including the first Vehicular status signal and the second Vehicular status signal obtained according to first Vehicular status signal, described first Vehicular status signal includes longitudinal acceleration signal；Ramp prediction signal and vehicle stabilization are obtained according to the Vehicular status signal Status signal；Judge whether vehicle travels on ramp according to the ramp prediction signal and the vehicle stabilization status signal； If it is, being filtered to the longitudinal acceleration signal, and determined according to filter result and the longitudinal acceleration signal The value of slope in ramp.

Further, first Vehicular status signal further include: wheel speed signal, yaw rate signal, master cylinder pressure Signal, ABS activation signal, TCS activation signal and VDC activation signal, second Vehicular status signal includes: wheel speed acceleration Signal, acceleration error signal and yaw velocity derivative signal, wherein the yaw velocity derivative signal is by the sideway Angular velocity signal derivation obtains, and the wheel speed acceleration signal is obtained by the wheel speed signal derivation, the acceleration error letter It number is calculated by the longitudinal acceleration signal and the wheel speed acceleration signal, the calculation formula are as follows:

AccelError=MAX [abs (AccelError-WhlVxLF_isg), abs (AccelError-WhlVxLR_ Isg), abs (AccelError-WhlVxRF_isg), abs (AccelError-WhlVxRR_isg)],

Wherein, the AccelError is acceleration error signal, and the WhlVxLF_isg is left front wheel speed signal, institute State that WhlVxRF_isg is off-front wheel speed signal, the WhlVxLR_isg is left back wheel speed signal, the WhlVxRR_isg is right Wheel speed signal afterwards.

Further, when the vehicle be two drive when, the ramp prediction signal is obtained by following formula, described Formula are as follows:

GradeEstimation=VehlonAccel-SUM (Driven WheelLongAccel)/2,

When the vehicle is four-wheel drive cars, the ramp prediction signal is obtained by following formula, the formula are as follows:

GradeEstimation=VehlonAccel-SUM (WheelLongAccel)/4,

Wherein, the GradeEstimation is ramp prediction signal, and the VehlonAccel is longitudinal acceleration Spend signal, the WheelLongAccel wheel speed acceleration signal.

Further, described that vehicle stabilization status signal is obtained according to Vehicular status signal, comprising: to judge acceleration error Whether signal is less than the first threshold value；If it is not, then the vehicle stabilization status signal is invalid；If it is, further judgement Whether yaw velocity is less than the second threshold value, if it is not, then the vehicle stabilization status signal is invalid；If it is, into one Step judges whether the yaw velocity derivative signal is less than third threshold value；If it is not, then the vehicle stabilization status signal In vain；If it is, further judging the master cylinder pressure signal whether less than the 4th threshold value；If it is not, then the vehicle Steady state signal is invalid；If it is, further whether judging ABS activation signal, TCS activation signal and VDC activation signal Effectively；If it is, the vehicle stabilization status signal is invalid, otherwise the vehicle stabilization status signal is effective.

Further, described to judge whether vehicle travels according to ramp prediction signal and the vehicle stabilization status signal On ramp, comprising: judge whether the absolute value of ramp prediction signal is greater than critical value；If it is not, then further judging that vehicle is steady Whether effective determine status signal；If it is, further judging whether the duration is greater than the crash time；If it is being then to sentence Determine vehicle not travel on ramp；If the absolute value of ramp prediction signal is greater than critical value, vehicle stabilization is further judged Whether status signal is effective；If it is, further judging whether the duration is greater than the crash time；If it is, determining vehicle Traveling on ramp.

Further, described that longitudinal acceleration signal is filtered, and according to filter result and the longitudinal acceleration Signal determines the value of slope in ramp, comprising: is filtered, is obtained described vertical to the longitudinal acceleration signal by following formula To the noise and interference signal of acceleration, wherein the formula are as follows:

Wherein, u is input signal, and T is execution cycle, and m is the variable of adjustable cutoff frequency；

The value of slope in the ramp is obtained according to the longitudinal acceleration signal and the noise and interference signal.

Slope detection method of the invention can be added as long as vehicle is equipped with longitudinal acceleration sensor based on longitudinal Speed signal is timely and accurately detects the gradient of road, activates corresponding vehicle function so as to the gradient based on road Can, promote the stability and reliability of vehicle climb and fall.Without increasing additional hardware, can be simple and convenient and accurately count The value of slope for calculating road, has the advantages that operation is simple and at low cost.

Second object of the present invention is to propose a kind of slope detection system.The slope detection system is additional without increasing Hardware, can value of slope simple and convenient and that road is accurately calculated, have the advantages that operation is simple and at low cost.

In order to achieve the above objectives, the technical scheme of the present invention is realized as follows:

A kind of slope detection system, comprising: signal processing module, for obtaining Vehicular status signal, wherein the vehicle Status signal includes the first Vehicular status signal and the second Vehicular status signal for being obtained according to first Vehicular status signal, First Vehicular status signal includes longitudinal acceleration signal；Ramp prediction module, for according to the Vehicular status signal Obtain ramp prediction signal；Vehicle stable state judgment module, for obtaining vehicle stabilization shape according to the Vehicular status signal State signal；Ramp index module, for judging that vehicle is according to the ramp prediction signal and the vehicle stabilization status signal No traveling is on ramp；Ramp is worth compensating module, for being in traveling when on ramp in vehicle, believes the longitudinal acceleration It number is filtered, and determines the value of slope in ramp according to filter result and the longitudinal acceleration signal.

Further, first Vehicular status signal further include: wheel speed signal, yaw rate signal, master cylinder pressure Signal, ABS activation signal, TCS activation signal and VDC activation signal, second Vehicular status signal includes: wheel speed acceleration Signal, acceleration error signal and yaw velocity derivative signal, wherein the yaw velocity derivative signal is by the sideway Angular velocity signal derivation obtains, and the wheel speed acceleration signal is obtained by the wheel speed signal derivation, the acceleration error letter It number is calculated by the longitudinal acceleration signal and the wheel speed acceleration signal, the calculation formula are as follows:

AccelError=MAX [abs (AccelError-WhlVxLF_isg), abs (AccelError-WhlVxLR_ Isg), abs (AccelError-WhlVxRF_isg), abs (AccelError-WhlVxRR_isg)],

Wherein, the AccelError is acceleration error signal, and the WhlVxLF_isg is left front wheel speed signal, institute State that WhlVxRF_isg is off-front wheel speed signal, the WhlVxLR_isg is left back wheel speed signal, the WhlVxRR_isg is right Wheel speed signal afterwards.

Further, whether the vehicle stable state judgment module is used for: judging acceleration error signal less than first Threshold value；If it is not, then the vehicle stabilization status signal is invalid；If it is, further judging whether yaw velocity is small In the second threshold value, if it is not, then the vehicle stabilization status signal is invalid；If it is, further judging the yaw angle Whether speed derivative signal is less than third threshold value；If it is not, then the vehicle stabilization status signal is invalid；If it is, into Whether one step judges the master cylinder pressure signal less than the 4th threshold value；If it is not, then the vehicle stabilization status signal is invalid； If it is, further judging ABS activation signal, TCS activation signal and VDC activation signal whether effectively；If it is, institute It is invalid to state vehicle stabilization status signal, otherwise the vehicle stabilization status signal is effective.

Possessed advantage is identical compared with the existing technology with above-mentioned slope detection method for the slope detection system, Details are not described herein.

Third object of the present invention is to propose a kind of vehicle, which, can letter without increasing additional hardware Just and the value of slope of road is accurately calculated in folk prescription, has the advantages that operation is simple and at low cost.

In order to achieve the above objectives, the technical scheme of the present invention is realized as follows:

A kind of vehicle is provided with the slope detection system as described in any one above-mentioned embodiment.

Possessed advantage is identical compared with the existing technology with above-mentioned slope detection system for the vehicle, herein no longer It repeats.

Detailed description of the invention

The attached drawing for constituting a part of the invention is used to provide further understanding of the present invention, schematic reality of the invention It applies example and its explanation is used to explain the present invention, do not constitute improper limitations of the present invention.In the accompanying drawings:

Fig. 1 is the flow chart of slope detection method described in one embodiment of the invention；

Fig. 2 is the obtained in slope detection method described in one embodiment of the invention according to the first Vehicular status signal The process flow diagram of two Vehicular status signals；

Fig. 3 is the ramp prediction signal driven in slope detection method described in one embodiment of the invention for two Predict flow chart；

Fig. 4 is in slope detection method described in one embodiment of the invention for the ramp prediction signal of four-wheel drive cars Predict flow chart；

Fig. 5 is the decision flow chart of vehicle stable state in slope detection method described in one embodiment of the invention；

Fig. 6 is the flow chart that ramp index is calculated in slope detection method described in one embodiment of the invention；

Fig. 7 is the flow chart that ramp value complement repays calculating in slope detection method described in one embodiment of the invention；

Fig. 8 is the structural block diagram of slope detection system described in another embodiment of the present invention.

Description of symbols:

Slope detection system 800, signal processing module 810, ramp prediction module 820, vehicle stable state judgment module 830, ramp index module 840, ramp are worth compensating module 850.

Specific embodiment

It should be noted that in the absence of conflict, the feature in embodiment and embodiment in the present invention can phase Mutually combination.

The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

Fig. 1 is the flow chart of slope detection method according to an embodiment of the invention.

As shown in Figure 1, slope detection method according to an embodiment of the invention, includes the following steps:

S101: Vehicular status signal is obtained, wherein Vehicular status signal is including the first Vehicular status signal and according to first The second Vehicular status signal that Vehicular status signal obtains.

In specific example of the invention, the first Vehicular status signal includes but is not limited to: longitudinal acceleration signal (vehLogAccel), wheel speed signal (wheelspeed), yaw rate signal (YawRate), master cylinder pressure signal (MCP), ABS activation signal (ABSActive), TCS activation signal (TCSActive), VDC activation signal (VDCActive), the second vehicle Status signal includes but is not limited to: wheel speed acceleration signal (wheelaccel), acceleration error signal (AccErro), sideway Angular velocity signal (YawRate), yaw velocity derivative signal (YawRatedot).

Wherein, yaw velocity derivative signal is obtained by the yaw rate signal derivation, wheel speed acceleration signal by Wheel speed signal derivation obtains, and acceleration error signal is calculated by longitudinal acceleration signal and wheel speed acceleration signal, calculates Formula are as follows:

AccelError=MAX [abs (AccelError-WhlVxLF_isg), abs (AccelError-WhlVxLR_ Isg), abs (AccelError-WhlVxRF_isg), abs (AccelError-WhlVxRR_isg)],

Wherein, AccelError is acceleration error signal, and WhlVxLF_isg is left front wheel speed signal, WhlVxRF_isg It is left back wheel speed signal for off-front wheel speed signal, WhlVxLR_isg, WhlVxRR_isg is off hind wheel speed signal.

Specifically, as shown in Fig. 2, needing yaw rate signal to carry out derivation to handle to obtain yaw velocity derivative Signal (YawRatedot) is no more than Ce_YawRateDotMax to the derivative setting range maximum value of yaw velocity after derivation (calibration value, the standard value are 16rad/s^2), minimum value is no more than Ce_YawRateDotMin (calibration value, the standard value For -16rad/s^2)；

Next need to the wheel speed signals of four wheels (left front wheel speed WhlVxLF_isg, off-front wheel speed WhlVxRF_isg, Left back wheel speed WhlVxLR_isg, off hind wheel speed WhlVxRR_isg) derivation is carried out, obtain the wheel acceleration signal of four wheels；

The longitudinal acceleration signal that wheel acceleration signal and longitudinal acceleration sensor further according to four wheels measure (VehLogAccel), acceleration error signal (AccelError) is calculated by above-mentioned formula.

S102: ramp prediction signal and vehicle stabilization status signal are obtained according to Vehicular status signal.

Specifically, as shown in figure 3, when vehicle be two drive when, ramp prediction signal is obtained by following formula, formula Are as follows:

GradeEstimation=VehlonAccel-SUM (Driven WheelLongAccel)/2,

As shown in figure 4, ramp prediction signal is obtained by following formula, formula when vehicle is four-wheel drive cars are as follows:

GradeEstimation=VehlonAccel-SUM (WheelLongAccel)/4,

Wherein, GradeEstimation is ramp prediction signal, and VehlonAccel is longitudinal acceleration signal, WheelLongAccel wheel speed acceleration signal.

Ramp prediction signal is the difference between vehicle acceleration and wheel acceleration, is to judge whether vehicle " is being stablized One key parameter of state ", if vehicle goes up a slope on ramp, ramp prediction signal is positive value, if vehicle is in ramp Climb and fall, then ramp prediction signal is negative value.

In addition, obtaining vehicle stabilization status signal according to Vehicular status signal, comprising: whether judge acceleration error signal Less than the first threshold value；If it is not, then the vehicle stabilization status signal is invalid；If it is, further judging yaw angle speed Whether degree is less than the second threshold value, if it is not, then the vehicle stabilization status signal is invalid；If it is, further judging institute State whether yaw velocity derivative signal is less than third threshold value；If it is not, then the vehicle stabilization status signal is invalid；If It is then further to judge the master cylinder pressure signal whether less than the 4th threshold value；If it is not, then the vehicle stabilization state letter It is number invalid；If it is, further judging ABS activation signal, TCS activation signal and VDC activation signal whether effectively；If It is that then the vehicle stabilization status signal is invalid, otherwise the vehicle stabilization status signal is effective.

Wherein, ABS refers to anti-lock braking system, and TCS refers to traction control system, and VDC refers to vehicle dynamic control.

Specifically, as shown in figure 5, vehicle stabilization status signal is to judge that can vehicle according to longitudinal acceleration sensor The key parameter of ramp value is calculated, vehicle is in steady state signal SteadyState=1, then it represents that can be according to longitudinal direction Accurate value of slope is calculated in the value of acceleration transducer measurement, otherwise SteadyState=0, and expression then cannot be in this kind In the case of accurately calculate the value of slope of road, the mode of the embodiment of the present invention is in steady state signal SteadyState=1 When (i.e.: effectively), the value of slope in longitudinal ramp of calculating.

As shown in connection with fig. 5, judge acceleration error signal whether be less than threshold value Ke_AxErrMax_Grade (calibration value, This standard value 9.8m/s^2), the SteadyState=0 if being not less than；If above-mentioned condition establishment continues to judge yaw angle Whether speed is less than threshold value Ke_YawRateMax_Grade (calibration value, this standard value 0.0524rad/s^2), if not Less than then SteadyState=0；If above-mentioned condition establishment continues to judge whether the derivative of yaw velocity is less than threshold value Ke_YawAccelMax_Grade (calibration value, this standard value 0.8rad/s^3), the SteadyState=0 if being not less than； If above-mentioned condition establishment continues to sentence whether master cylinder pressure is less than threshold value Ke_McylPresMax_Grade (calibration value), if Not less than then SteadyState=0；If whether above-mentioned condition establishment, which continues to sentence ABS/VDC/TCS function to trigger, (that is: has Effect), if ABS/VDC/TCS function triggers, SteadyState=0, if it is not, SteadyState=1.

S103: judge whether vehicle travels on ramp according to ramp prediction signal and vehicle stabilization status signal.

Specifically, judge whether the absolute value of ramp prediction signal is greater than critical value；If it is not, then further judging vehicle Whether steady state signal is effective；If it is, further judging whether the duration is greater than the crash time；If it is being, then Determine that vehicle does not travel on ramp；If the absolute value of ramp prediction signal is greater than critical value, further judge that vehicle is steady Whether effective determine status signal；If it is, further judging whether the duration is greater than the crash time；If it is, determining Vehicle driving is on ramp.

As shown in fig. 6, whether ramp index GradeIndex is for judging vehicle at steady state in longitudinal ramp Traveling, at steady state, if GradeIndex=1, then it represents that vehicle travels on ramp, if GradeIndex=0, Indicate that vehicle does not travel on ramp.

As shown in connection with fig. 6, first determine whether the absolute value of GradeEstimation is greater than critical value Ke_ GradeOnThrshd (calibration value, this standard value 0.97m/s^2), continues to judge SteadyState if condition is invalid Whether it is equal to 1, if SteadyState=1, continues judgement and state whether condition establishment duration is greater than critical value GradeoffTime, if condition sets up GradeIndex=0；

If the absolute value of GradeEstimation is greater than critical value Ke_GradeOnThrshd (calibration value), continue Judge whether SteadyState is equal to 1, if condition is set up, continues to judge that above-mentioned condition sets up whether duration is greater than Critical value GradeoffTime, if being sustained for longer than critical value GradeoffTime, GradeIndex=1 (that is: vehicle It is travelled on ramp).

S104: if it is, being filtered to longitudinal acceleration signal, and according to filter result and longitudinal acceleration signal Determine the value of slope in ramp.

In specific example, longitudinal acceleration signal can be filtered by following formula, obtain longitudinal acceleration Noise and interference signal, wherein formula are as follows:

Wherein, u is input signal, and T is execution cycle, and m is the variable of adjustable cutoff frequency, in the present invention m= 0.0039；

Then, the value of slope in ramp is obtained according to longitudinal acceleration signal and noise and interference signal.

As shown in fig. 7, it is since vehicle accelerates that the numerical value of longitudinal acceleration sensor, which is dimeric a part, Or caused by slowing down, another part is that longitudinal acceleration sensor is made to generate acceleration due to ramp.As shown in fig. 7, working as ramp When index GradeIndex=0, indicate that vehicle does not travel on ramp at this time, value of slope at this time is 0.When ramp index is believed When number GradeIndex=1, high-pass filtering, warp are carried out to longitudinal acceleration signal Vehlonaccel by above-mentioned formula first The noise for being longitudinal direction of car acceleration obtained after high-pass filtering and interference signal are crossed (such as due to vehicle accelerates or slight system The fluctuation of longitudinal acceleration caused by dynamic), signal is denoted as AXHP, the longitudinal acceleration then measured with longitudinal acceleration sensor Subtract that noise figure obtains is exactly the acceleration that longitudinal acceleration sensor caused by ramp generates.So the value of slope of road is such as Shown in lower formula:

θ=arsin (vehlonaccel-AXHP).

Slope detection method according to an embodiment of the present invention can as long as vehicle is equipped with longitudinal acceleration sensor Detect the gradient of road in time and accurately based on longitudinal acceleration signal, it is corresponding so as to the gradient activation based on road Vehicle functions, promoted vehicle climb and fall stability and reliability.Without increasing additional hardware, can it is simple and convenient and The value of slope of road is accurately calculated, has the advantages that operation is simple and at low cost.

Fig. 8 is the structural block diagram of slope detection system according to an embodiment of the invention.As shown in figure 8, according to this hair The slope detection system 800 of bright one embodiment, comprising: signal processing module 810, ramp prediction module 820, vehicle stablize shape State judgment module 830, ramp index module 840 and ramp are worth compensating module 850.

Wherein, signal processing module 810 is for obtaining Vehicular status signal, wherein the Vehicular status signal includes the One Vehicular status signal and the second Vehicular status signal obtained according to first Vehicular status signal, the first vehicle shape State signal includes longitudinal acceleration signal.Ramp prediction module 820 is used to obtain ramp prediction according to the Vehicular status signal Signal.Vehicle stable state judgment module 830 is used to obtain vehicle stabilization status signal according to the Vehicular status signal.Ramp Index module 840 is used to judge whether vehicle travels on slope according to the ramp prediction signal and the vehicle stabilization status signal On road.Ramp is worth compensating module 850 and is used to be in traveling when on ramp in vehicle, filters to the longitudinal acceleration signal Wave, and determine according to filter result and the longitudinal acceleration signal value of slope in ramp.

In one embodiment of the invention, the first Vehicular status signal further include: wheel speed signal, yaw velocity letter Number, master cylinder pressure signal, ABS activation signal, TCS activation signal and VDC activation signal, the second Vehicular status signal packet It includes: wheel speed acceleration signal, acceleration error signal and yaw velocity derivative signal, wherein the yaw velocity derivative Signal is obtained by the yaw rate signal derivation, and the wheel speed acceleration signal is obtained by the wheel speed signal derivation, institute It states acceleration error signal to be calculated by the longitudinal acceleration signal and the wheel speed acceleration signal, the calculation formula Are as follows:

AccelError=MAX [abs (AccelError-WhlVxLF_isg), abs (AccelError-WhlVxLR_ Isg), abs (AccelError-WhlVxRF_isg), abs (AccelError-WhlVxRR_isg)],

Wherein, the AccelError is acceleration error signal, and the WhlVxLF_isg is left front wheel speed signal, institute State that WhlVxRF_isg is off-front wheel speed signal, the WhlVxLR_isg is left back wheel speed signal, the WhlVxRR_isg is right Wheel speed signal afterwards.

In one embodiment of the invention, vehicle stable state judgment module 830 is used for: judging acceleration error signal Whether less than the first threshold value；If it is not, then the vehicle stabilization status signal is invalid；If it is, further judging sideway Whether angular speed is less than the second threshold value, if it is not, then the vehicle stabilization status signal is invalid；If it is, further sentencing Whether the yaw velocity derivative signal that breaks is less than third threshold value；If it is not, then the vehicle stabilization status signal is invalid； If it is, further judging the master cylinder pressure signal whether less than the 4th threshold value；If it is not, then the vehicle stabilization shape State invalidating signal；If it is, further judging ABS activation signal, TCS activation signal and VDC activation signal whether effectively； If it is, the vehicle stabilization status signal is invalid, otherwise the vehicle stabilization status signal is effective.

Slope detection system according to an embodiment of the present invention can as long as vehicle is equipped with longitudinal acceleration sensor Detect the gradient of road in time and accurately based on longitudinal acceleration signal, it is corresponding so as to the gradient activation based on road Vehicle functions, promoted vehicle climb and fall stability and reliability.Without increasing additional hardware, can it is simple and convenient and The value of slope of road is accurately calculated, has the advantages that operation is simple and at low cost.

It should be noted that the specific implementation and the embodiment of the present invention of the slope detection system of the embodiment of the present invention The specific implementation of slope detection method is similar, specifically refers to the description of method part, in order to reduce redundancy, does not do herein It repeats.

Further, it embodiment of the invention discloses a kind of vehicle, is provided with as in any one above-mentioned embodiment Slope detection system.As long as the vehicle is equipped with longitudinal acceleration sensor, can based on longitudinal acceleration signal in time and It accurately detects the gradient of road, activates corresponding vehicle functions so as to the gradient based on road, promote vehicle or more The stability and reliability on slope.It, can the gradient simple and convenient and that road is accurately calculated without increasing additional hardware Value, has the advantages that operation is simple and at low cost.

In addition, other compositions of vehicle according to an embodiment of the present invention and effect are for those of ordinary skill in the art For be all it is known, in order to reduce redundancy, be not repeated herein.

The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention Within mind and principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.