CN104057952A - Ramp resistance obtaining method for hybrid electric vehicle - Google Patents

Abstract

The invention provides a ramp resistance obtaining method for a hybrid electric vehicle to solve the problems that ramp resistance calculation methods are lower in accuracy and deviation occurs easily in the prior art. According to the ramp resistance obtaining method, the driving force and the resistance of the vehicle are comprehensively considered, a vehicle dynamics equation is established accordingly, the acceleration resistance, the sliding resistance and the like outside the vehicle are considered during conversion, meanwhile, the inertia resistance caused by all rotating parts inside the vehicle is further considered, due to comprehensive consideration, the estimated ramp resistance is accurate and reliable with the obtaining method, and an important basis is provided for a shifting strategy, an SOC (state of charge) balance strategy and a torque distribution strategy for ramps.

Description

A kind of hybrid vehicle gradient resistance acquisition methods

Technical field

The present invention relates to technical field of automotive electronics, especially refer to the gradient resistance evaluation method of hybrid vehicle.

Background technology

Technology of Hybrid Electric Vehicle comes to the ripening period at present, and the technology such as fuel cell technology, pure electrokinetic technique, combustion hydrogen engine, substitute fuel, owing to being subject to the restriction of a series of problems such as technical bottleneck and infrastructure construction, are also in the research and development phase.Therefore, the marketization of hybrid vehicle at present will seem more important, in the R&D process of hybrid vehicle, the technology such as battery module, dynamic assembly, hybrid power whole vehicle controller (HybridControl Unit is called for short HCU) are the difficult points of hybrid vehicle research and development.

Wherein HCU realizes control, coordination and the energy distribution of the power nodes such as driving engine node in whole motor vehicle driven by mixed power, motor node and battery node, also be responsible for the control of whole vehicle shift strategy and battery electric quantity equilibrium strategy etc., be the core that whole vehicle is controlled simultaneously.

In the process that vehicle moves on actual road, except being subject to the demand control of chaufeur, also be subject to the impact of the operating mode on road surface, in the road condition that affects car load control, the gradient is one of critical influence factor, different gradient resistance corresponding to ramp.Different gradient resistances can produce larger impact to the Shifting of entire car controller, if do not consider ramp factor, on ramp, can cause the frequent problem of switching of gear, the so-called shelves of frequently cutting refer to that chaufeur improves power by dark step on the accelerator in the process of going up a slope, but the existence due to ramp, the speed of a motor vehicle can not rise according to the intention of the acceleration of actual chaufeur, and speed of a motor vehicle rising has caused mode that vehicle has to lower category to provide power for vehicle; When the speed of a motor vehicle reaches after certain speed, the gear of vehicle becomes again original gear again; So just caused the gear switch of twice, therefore in the process of going up a slope, the variation of speed of a motor vehicle delay throttle has caused the gear of vehicle frequently to switch; Simultaneously in the process of motor vehicle driven by mixed power climbing, owing to there being larger gradient resistance, the moment of torsion that motor is assigned in the situation that moving according to driven strategy is larger, can cause its battery charge state (State of Charge, be called for short SOC) always lower in the process of climbing, affect the balance control policy of whole vehicle SOC.

Therefore, gradient resistance evaluation method for new-energy automobile seems particularly important, at present, two kinds of methods of main employing obtain gradient resistances, a kind of method is to adopt pointwise Static Detection technology, installation and measuring Equipment Inspection road information on vehicle, obtains the gradient of road, and then calculates the grade resistance of vehicle.Yet detection and the maintenance workload of the precision of this kind of method are large, and efficiency is low, and this technology is vulnerable to the enchancement factors such as gearshift impacts, Uneven road and disturbs, and easily accumulates and occurs error.Method is a method that adopts kinetics equation, gathers the parameters of car load, as information acquisition gradient resistances such as the speed of a motor vehicle, vehicle acceleration, complete vehicle qualities.But current dynamic estimation method is mainly applicable to conventional truck, the factor of its consideration is less, and method of calculating is comparatively simple.Such as having provided a kind of gradient resistance method of calculating in prior art, it is after obtaining the speed information of vehicle, differential obtains vehicle acceleration, and obtain a resultant acceleration information by sensor, this resultant acceleration information is the vector of vehicle acceleration and acceleration due to gravity, again by calculating the component of acceleration due to gravity, thereby the acquisition gradient, and obtain grade resistance, this method is owing to mainly only considering vehicle acceleration, do not consider the output torque of its vehicle, various resistance factors etc., its gradient resistance method of calculating precision is lower, easily occurs deviation.

Summary of the invention

Lower for solving existing gradient resistance evaluation method precision, the problem that easily occurs deviation, the invention provides a kind of hybrid vehicle gradient resistance acquisition methods, described hybrid vehicle comprises driving engine, ISG motor, rear motor, front gear box, rear speed-changing mechanism, front driving axle and rear driving axle; The output shaft of described driving engine connects described front driving axle at the described ISG motor of connection by described front gear box, and described rear motor speed-changing mechanism after described connects described rear driving axle;

Wherein, described hybrid vehicle gradient resistance acquisition methods comprises the steps:

Obtain the speed ratio n of described front gear box ₁, described rear speed-changing mechanism speed ratio n ₂, tire radius r and complete vehicle quality m;

By measuring and calculating, obtain the output torque T of described driving engine _eMS, described ISG motor output torque T _iSG, and the output torque T of described rear motor _eRAD;

Coast-down check by vehicle obtains resistance of taxing F _c;

By the speed of a motor vehicle difference of vehicle, obtained the car load acceleration/accel of vehicle then pass through expression formula obtain car load resistance due to acceleration F _acc;

According to the rotor inertia of rotatable parts on vehicle and angular acceleration, obtain car load inertia resistance F _j;

According to the parameter of above-mentioned acquisition, adopt following expression formula estimation to obtain gradient resistance F _slope:

F _Slope=[T _EMS+T _ISG]n ₁/r+T _ERAD·n ₂/r-F _C-F _Acc-F _j。

Adopt hybrid vehicle gradient resistance acquisition methods provided by the invention, in the process of estimation, propulsive effort and the vehicle drag of vehicle have been considered comprehensively, and set up thus vehicle dynamics equation, in conversion process, not only considered the resistance due to acceleration of outside vehicle, resistance of taxing etc., further considered the inertia resistance that each rotatable parts of vehicle interior bring simultaneously, owing to considering comprehensively, this acquisition methods has guaranteed that the gradient resistance that estimates accurately and reliably, for the Shifting on ramp, SOC equilibrium strategy and torque distribution strategy provide important foundation.

Accompanying drawing explanation

Fig. 1 is the hybrid vehicle configuration schematic diagram that the embodiment of the present invention provides;

Fig. 2 slides curve of resistance schematic diagram under the different speed of a motor vehicle that provide of the embodiment of the present invention;

Fig. 3 is the rear motor angular acceleration that the embodiment of the present invention provides estimation diagram of circuit;

Fig. 4 is the engine output shaft angular acceleration that the embodiment of the present invention provides diagram of circuit;

Fig. 5 is the tire angular acceleration that the embodiment of the present invention provides estimation diagram of circuit;

Fig. 6 is the vehicle acceleration that the embodiment of the present invention provides estimation diagram of circuit.

The specific embodiment

In order to make technical matters solved by the invention, technical scheme and beneficial effect clearer, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein, only in order to explain the present invention, is not intended to limit the present invention.

Contriver is doing after large quantity research this hybrid vehicle and gradient resistance acquisition methods thereof, find that in currently available technology, ramp drag computation method precision is lower, easily occur deviation, simultaneously, gradient resistance acquisition methods for hybrid vehicle, does not have referential experience yet.This part will to hybrid vehicle as simple description after, provide the gradient resistance acquisition methods based on this hybrid vehicle.

The present invention is based on a kind of hybrid vehicle, for simplicity, first this hybrid vehicle is explained, but object of the present invention is not that a kind of hybrid vehicle is provided, and be to provide a kind of gradient resistance acquisition methods based on this hybrid vehicle.As shown in Figure 1, this hybrid vehicle comprises driving engine, ISG(Integrated Starter Generator, Chinese name: integrated actuating motor) motor, rear motor, front gear box, rear speed-changing mechanism, front driving axle and rear driving axle; The output shaft of described driving engine connects front driving axle by front gear box connecting ISG motor, described rear motor through after speed-changing mechanism connection rear driving axle.Wherein, in figure, battery module is for ISG motor and rear motor provide power, and the direct current (DC) (line of single-point shown in figure represents direct current) that being specially this battery module provides is converted to alternating current (long and two-short dash line shown in figure represents to exchange) and offers ISG motor and rear motor after inverter.Meanwhile, be connected with a DC/DC (DirectCurrent to Direct Current, Chinese name: DC-DC converter), this DC/DC connects a storage battery power supply with inverter.Described storage battery is used to the electrical equipment of the control units such as instrument on car that power supply is provided, and meanwhile, DC/DC also provides charge function, for storage battery supplements electric weight.

ISG motor is directly integrated on engine output shaft, the technology such as motor, modern power electronic, digital signal processing, modern control have been merged, the starting and the electricity generate function that integrate orthodox car, there is outstanding rise/stopping and control the advantages such as fast, energy regeneration is made good use of, power-assisted is strong, especially successful aspect reduction exhaust pollution, capable of saving fuel oil.

Described front gear box is conventionally known to one of skill in the art, and for realizing change gear multiplication, this routine front gear box is provided with 5 grades, and navigating mate can select suitable gear to be suitable for the different speed of a motor vehicle as required.Different gears means different gear multiplication (also claiming speed ratio).

Rear speed-changing mechanism is used for exporting fixed speed ratio, and power is passed to rear driving axle from motor.

Front driving axle, rear driving axle are generally by compositions such as main reduction gear, diff, axle drive shaft (left and right half) and driving axle housings.Its effect is that the power that universal driving device (connection for transmission axle) is transmitted was rolled over 90 ° of angles, changes the direction of transfer of power, and reduces rotating speed by main reduction gear, increases after torque, through diff, distributes to left and right half (as axle drive shaft) and drive wheel.Main reduction gear is generally used for changing transmission direction, reduces rotating speed, increases moment of torsion, guarantees that automobile has enough propulsive efforts and suitable speed.Diff, in order to connect left and right semiaxis, can make both sides tire with different cireular frequency rotation while transmitting torques.Guarantee the normal rolling of tire.Semiaxis is that the moment of torsion that diff is transmitted is passed to tire again, tire on the drive wheels rotation, the solid axle that propelling vehicle travels.

The left and right half of front driving axle is called to front axle, the left and right semiaxis of rear driving axle is called to rear axle.

Transmission shaft refers to the axle to drive axle by front gear box transmission of power, and the transmission shaft between front gear box and front driving axle is called front propeller shaft, and the transmission shaft between rear speed-changing mechanism and rear driving axle is called rear propeller shaft.

Certainly, also comprise HCU, engine management system (Engine Management System, abbreviation EMS), front gear box control unit (Transmission Control Unit, abbreviation TCU), battery management system (Battery Management System, be called for short BMS) and brake controller (Brake ControllerSystem is called for short BCS) dispatch control system.As shown in Figure 1, the signal wire (SW) that hybrid power whole vehicle controller HCU represents by dotted line in figure is controlled the control units such as engine management system EMS, front gear box control unit TCU, battery management system BMS, brake controller BCS.Hybrid power whole vehicle controller HCU is responsible for the coordinated control function such as energy distribution, gearshift control and driver intention analysis of whole vehicle.Engine management system EMS realizes functions such as the control of driving engine, reading command, transmission data, front gear box control unit TCU realizes the functions such as the control of front gear box, reading command, transmission data, battery management system BMS is realized the management of the electric weight of battery module, temperature etc. is controlled, and brake controller BCS realizes functions such as the drg control of (claiming again brake), reading command, transmission data.

Embodiment 1

This example, based on the above-mentioned hybrid vehicle providing, has provided a kind of method of obtaining this hybrid vehicle gradient resistance, comprises the steps:

Obtain the speed ratio n of front gear box ₁, rear speed-changing mechanism speed ratio n ₂, tire radius r and complete vehicle quality m;

By measuring and calculating, obtain the output torque T of driving engine _eMS, ISG motor output torque T _iSG, and the output torque T of rear motor _eRAD;

Coast-down check by vehicle obtains resistance of taxing F _c;

Speed of a motor vehicle difference by vehicle obtains whole vehicle acceleration/accel then pass through expression formula obtain car load resistance due to acceleration F _acc;

According to the rotor inertia of rotatable parts on vehicle and angular acceleration, obtain car load inertia resistance F _j;

According to the parameter of above-mentioned acquisition, adopt following expression formula 1. to estimate and obtain gradient resistance F _slope:

F _Slope=[T _EMS+T _ISG]n ₁/r+T _ERAD·n ₂/r-F _C-F _Acc-F _j。①

Adopt hybrid vehicle gradient resistance acquisition methods provided by the invention, in the process of estimation, propulsive effort and the vehicle drag of vehicle have been considered comprehensively, and set up thus vehicle dynamics equation, in conversion process, not only considered the resistance due to acceleration of outside vehicle, resistance of taxing etc., further considered the inertia resistance that each rotatable parts of vehicle interior bring simultaneously, owing to considering comprehensively, this acquisition methods has guaranteed that the gradient resistance that estimates accurately and reliably, for the Shifting on ramp, SOC equilibrium strategy and torque distribution strategy provide important foundation.Meanwhile, with respect to existing method, in the acquisition methods that this example provides, parameters is very easy to obtain from vehicle, calculates simply, has greatly simplified the process of obtaining.

By estimating that gradient resistance is as a parameter of controlling gearshift figure accurately, can effectively solve the shift hunting problem of bringing due to gradient resistance, using the gradient resistance of estimation as a parameter of torque distribution, thereby the rear motor torque distribution amount on ramp of can being effectively controlled at solves the low problem always of SOC on ramp.

Wherein, the numerical value of the radius r of tire can obtain by actual measurement tire; n ₁be the output speed ratio of front gear box 1-5 shelves, can calculate according to the current gear of front gear box; n ₂be the speed ratio of rear axle, this numerical value can draw according to the fixed speed ratio of rear speed-changing mechanism;

About the rotor inertia of the rotatable parts on vehicle, we know that the value of rotor inertia depends on the position of shape, mass distribution and the rotating shaft of object.Therefore after vehicle moulding, it must be certain value, can be by using test equipment and the method for the rotor inertia of current maturation to measure.Hybrid power whole vehicle controller can read by bus the rotor inertia of each rotatable parts.

For the angular acceleration of rotatable parts, can obtain after the rotating speed of rotatable parts by sensor, to described rotating speed difference derivation, can obtain corresponding angular acceleration.

For described car load inertia resistance F _jafter obtaining the rotor inertia and angular acceleration of rotatable parts, both are multiplied each other and can obtain the inertia resistance square of rotatable parts, according to this inertia resistance square, can obtain corresponding inertia resistance, in general, for ease of calculating, the inertia resistance square of each rotatable parts can be converted to tire end, then be obtained the inertia resistance after conversion according to tire radius.Obviously, the inertia resistance that on overall consideration vehicle, all rotatable parts bring, its car load inertia resistance F _jresult accuracy rate can be higher, but in actual estimation process, the proportion accounting between each rotatable parts is different, the inertia resistance proportion that some rotatable parts bring is large, and the inertia resistance proportion that some rotatable parts bring is little, in actual estimation process, also can only consider the larger rotatable parts of some proportion to calculate inertia resistance, and neglect the inertia resistance that proportion is less, and its estimation precision is higher like this, and its estimation process is simplified.

As a kind of optimal way, described whole vehicle acceleration/accel preferably by following estimation steps, obtain: as shown in Figure 6, first by brake controller, obtain vehicle speed signal, specifically refer to that the wheel speed signal calculating by four tires obtains vehicle speed signal by brake controller, and by bus, upload vehicle speed signal by brake controller in hybrid controller HCU;

Then to vehicle speed signal, adopt low-pass first order filter to carry out filtering, get rid of due to the interfere information of bringing in sampling process;

Then the vehicle speed signal differentiate after removal interfere information is obtained the acceleration signal of vehicle;

To described acceleration signal, adopt low-pass first order filter to carry out filtering again and get rid of due to fluctuating widely that calculating causes, thereby obtain described whole vehicle acceleration/accel

T _eMSfor the output torque of driving engine, can pass through by engine management system suction quantity and the timing of ignition calculating acquisition of engine air throttle; Specifically comprise the steps: to calculate according to the aperture of throttle gate the numerical value of suction quantity; According to the moment calculating timing of ignition of ignition angle; Then according to the aperture of throttle gate and timing of ignition, table look-up and draw the output torque of driving engine, engine management system sends to hybrid power whole vehicle controller by bus by moment of torsion data.

T _iSGfor the output torque of ISG motor, by ISG motor, by detecting the electric current estimation of its AC, drawn; ISG motor sends the data to hybrid power whole vehicle controller by bus.

T _eRADfor the output torque of rear motor, by rear motor controller, according to the electric current estimation of its AC, drawn; Rear motor controller sends the data to hybrid power whole vehicle controller by bus.

The vehicle sliding resistance F mentioning in this example _c, it comprises the rolling resistance F of vehicle _rollwith air resistance F _air, contriver finds that these two parameters are only relevant with speed with the structure of vehicle, these two parameters can synthesize the resistance of taxing F that a drag parameter is vehicle _c, the resistance of taxing F of vehicle _ccoast-down check by vehicle obtains, and Fig. 2 is the resistance of taxing curve recording under the different speed of a motor vehicle on studied vehicle.Measure the corresponding relation of this speed of a motor vehicle and resistance of taxing, as long as known car speed, can obtain the resistance of taxing of this correspondence speed of a motor vehicle.As long as the data of storing this car speed and resistance of taxing on hybrid power new forms of energy car, call this partial data at any time.

Wherein, as a kind of optimal way, describedly according to the rotor inertia of rotatable parts on vehicle and angular acceleration, obtain car load inertia resistance and specifically comprise the steps:

According to rotor inertia corresponding to front driving axle and angular acceleration estimation, obtain described front driving axle inertia resistance F _jf, according to rotor inertia corresponding to rear driving axle and angular acceleration, estimation obtains described rear driving axle inertia resistance F _jraccording to rotor inertia corresponding to tire end and angular acceleration, estimation obtains the inertia resistance F of described tire _jt;

Then by described front driving axle inertia resistance F _jf, described rear driving axle inertia resistance F _jrand the inertia resistance F of described tire _jtsummation obtains described car load inertia resistance, by following expression, 2. obtains car load inertia resistance F _j:

F _j=F _jf+F _jr+F _jt； ②

Wherein, described front driving axle inertia resistance F _jfobtain as follows:

Measuring and calculating obtains engine output shaft angular acceleration

As a kind of optimal way, described engine output shaft angular acceleration estimation steps is specific as follows: as shown in Figure 4, the engine rotational speed signal that driving engine is come by bus transfer converts angular velocity signal to, and described cireular frequency can by ISG motor or engine controller detects and by bus, angular velocity information correspondence is uploaded in hybrid power whole vehicle controller HCU;

To described angular velocity signal, adopt low-pass first order filter to carry out filtering to get rid of due to the interfere information of bringing in sampling process;

The described angular velocity signal differentiate of removing after interfere information is obtained to angular acceleration signal;

To described angular acceleration signal, adopt low-pass first order filter to carry out filtering to get rid of due to fluctuating widely that calculating causes, thereby obtain engine output shaft angular acceleration

Measuring and calculating obtains the rotor inertia J of engine crankshaft _eMSand the rotor inertia J of ISG rotor _iSG; For above-mentioned two rotor inertias, hybrid power whole vehicle controller all can be directly from bus read or convert after obtain this value.

Then according to following expression, 3. obtain described front driving axle inertia resistance F _jf:

$F_{\mathrm{jf}}=(J_{\mathrm{EMS}}+J_{\mathrm{ISG}}){\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{EMS}}\·n_1/r.$ ③

This expression formula has been expressed the front driving axle inertia resistance F that front driving axle is folded to after front gear box to tire end _jf.

Described rear driving axle inertia resistance F _jrobtain as follows:

Measuring and calculating obtains rear motor angular acceleration

As a kind of optimal way, rear motor angular acceleration estimation steps is specific as follows: as shown in Figure 3, the rear motor tach signal that rear motor is come by bus transfer converts angular velocity signal to, be that rear motor controller obtains the tach signal of its rear motor and is converted to after angular velocity signal, by bus, this angular velocity signal uploaded in hybrid power whole vehicle controller HCU.

Adopt low-pass first order filter to carry out filtering processing to described angular velocity signal to remove the interfere information of bringing in sampling process;

The described angular velocity signal differentiate (being difference) of removing after interfere information is obtained to angular acceleration signal;

To described angular acceleration signal, adopt low-pass first order filter to carry out filtering to get rid of due to fluctuating widely that calculating causes, thereby obtain described rear motor angular acceleration

Measuring and calculating obtains the total rotor inertia J of rear axle _eRAD; Hybrid power whole vehicle controller can be directly from bus read or convert after obtain this value.

Then by following expression, 4. obtain described rear driving axle inertia resistance F _jr:

$F_{\mathrm{jr}}=J_{\mathrm{ERAD}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{ERAD}}\·n_2/r.$ ④

This expression formula expressed rear driving axle through after be folded to the rear driving axle inertia resistance F of tire end after speed-changing mechanism _jr.

The inertia resistance F of described tire _jtobtain as follows;

Measuring and calculating obtains the rotor inertia J for tire and front gear box _tyer; Hybrid power whole vehicle controller can be directly from bus read or convert after obtain this value.

Measuring and calculating obtains tire angular acceleration

As a kind of optimal way, described tire angular acceleration estimation steps is specific as follows: as shown in Figure 5, the tire rotational speed signal that brake controller is come by bus transfer becomes angular velocity signal, is specially tire rotational speed signal and by brake controller, by wheel speed sensors, is obtained and upload in hybrid power whole vehicle controller HCU by bus;

To angular velocity signal, adopt low-pass first order filter to carry out filtering, to remove due to the interfere information of bringing in sampling process;

The angular velocity signal differentiate of removing after interfere information is obtained to angular acceleration signal;

To described angular acceleration signal, adopt low-pass first order filter to carry out filtering to get rid of due to fluctuating widely that calculating causes, thereby obtain described tire angular acceleration

Then by following expression, 5. estimate the inertia resistance F that obtains described tire _jt:

$F_{\mathrm{jt}}=J_{\mathrm{Tyer}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{Tyer}}/r.$ ⑤

As a kind of optimal way, by expression formula 3., 4., 5., substitution expression formula 2. in, then by 2. substitution expression formula of expression formula 1. in, obtain expression formula and be 6. used for estimating described gradient resistance;

$F_{\mathrm{Slope}}=[T_{\mathrm{EMS}}+T_{\mathrm{ISG}}]n_1/r+T_{\mathrm{ERAD}}\·n_2/r$

$-(J_{\mathrm{EMS}}+J_{\mathrm{ISG}}){\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{EMS}}\·n_1/r-J_{\mathrm{ERAD}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{ERAD}}\·n_2/r-J_{\mathrm{Tyer}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{Tyer}}/r$ ⑥

$-F_C-F_{\mathrm{Acc}}$

Above-mentioned optimal way has provided concrete car load inertia resistance computation process, the rotor inertia of its each rotatable parts can be directly by test or directly read from bus, and after obtaining the rotating speed of rotatable parts, can simple push derive the angular acceleration of rotatable parts; Can obtain the inertia resistance that each rotatable parts bring thus comprehensively.Owing to having considered the inertia resistance of the rotatable parts such as driving engine, ISG motor, rear motor, tire comprehensively, the gradient resistance therefore obtaining more accurately and reliably.

6. above-mentioned expression formula is done to part and merge after distortion, obtain following expression 7., this expression formula is 7. same, and 6. essence is identical with expression formula.But can have different understanding, 6. expression formula represents that first by the output torque of front driving axle and the output torque of rear driving axle, obtaining front driving axle propulsive effort adds after rear driving axle propulsive effort, deducts inertia resistance, resistance of taxing and the resistance due to acceleration of car load.And 7. expression formula is first to deduct with the output torque of front driving axle the inertia resistance square that front driving axle is corresponding, obtain effective propulsive effort of front driving axle, equally, first with the output torque of rear driving axle, deduct inertia resistance square corresponding on rear driving axle, and then effective propulsive effort of acquisition rear driving axle, can understand like this, be about to inertia resistance as to propulsive effort restriction, deduct again its resistance of taxing and resistance due to acceleration after first obtaining effective propulsive effort of car load.

$F_{\mathrm{Slope}}=[T_{\mathrm{EMS}}+T_{\mathrm{ISG}}-(J_{\mathrm{EMS}}+J_{\mathrm{ISG}}){\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{EMS}}]n_1/r-J_{\mathrm{Tyer}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{Tyer}}/r$

$+(T_{\mathrm{ERAD}}-J_{\mathrm{ERAD}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{ERAD}})n_2/r$ ⑦

$-F_C-F_{\mathrm{Acc}}$

Due at rear motor angular acceleration engine output shaft angular acceleration tire angular acceleration whole vehicle acceleration/accel these 4 parameters are in the process of estimation, after obtaining initialize signal, carried out single order low-pass filtering treatment, removed the interfering process bringing in employing process, and after filtering signal difference derivation, carried out again one time single order low-pass filtering treatment, removed fluctuating widely of bringing in computation process, therefore the result that, its estimation obtains more accurately and reliably.

For making those skilled in the art further understand the gradient resistance acquisition methods that this example provides, 7. the expression formula of take is example, obtains this expression formula be below 7. specifically described how to derive.

Derivation comprises the steps:

Effective output torque T of SA, calculating front axle mouth _frtAxand effective output torque T of rear axle mouth _rrAx; The present invention is based on three propulsion source hybrid vehicle systems, its propulsive effort comprises the propulsive effort of front driving axle and rear driving axle.This step is the effective output torque T to front axle mouth first _frtAxeffective output torque T with rear axle mouth _rrAxcalculate, because moment of torsion (or torque) is the product of the propulsive effort of the perpendicular direction of the radius of gyration, according to this relation, can in subsequent step, output torque be converted to propulsive effort.

Specifically comprise the steps:

Obtain the output torque T of driving engine _eMS, ISG motor output torque T _iSG, engine output shaft angular acceleration the rotor inertia J of engine crankshaft _eMS, ISG rotor rotor inertia J _iSG, tire and front gear box rotor inertia J _tyer, and tire angular acceleration the speed ratio n of front gear box ₁after.

Then by following expression, 8. estimate effective output torque T of described front axle mouth _frtAx:

$T_{\mathrm{FrtAx}}=[T_{\mathrm{ENS}}+T_{\mathrm{ISG}}-(J_{\mathrm{EMS}}+J_{\mathrm{ISG}}){\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{EMS}}]n_1-J_{\mathrm{Tyer}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{Tyer}}$ ⑧

Above-mentioned expression formula 8. in, the implication of expression be the output torque of front axle mouth synthetic by the moment of torsion of driving engine and ISG motor (be expression formula T _eMS+ T _iSG) after, deducting the inertia resistance square that the inertia resistance of its engine inertia resistance and motor brings (is expression formula (J _eMS+ J _iSG) ), after after front gear box amplifies, output to front axle, also deduct the inertia resistance square that inertia resistance that tire and front gear box bring brings (is expression formula simultaneously ).

Obtain the output torque T of rear motor _eRAD, the total rotor inertia J of rear axle _eRAD, rear motor angular acceleration and the speed ratio n of rear axle ₂;

Then by following expression, 9. estimate effective output torque T of described rear axle mouth _rrAx:

$T_{\mathrm{RrAx}}=[T_{\mathrm{ERAD}}-J_{\mathrm{ERAD}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{ERAD}}]n_2$ ⑨

In above-mentioned expression formula, the implication of expression is that effective output torque of rear axle mouth is deducted after the inertia resistance square that its rear motor inertia resistance brings through fixing speed reduction gearing (speed-changing mechanism) amplification and drawn by rear motor output torque.

SB, calculating obtain the effective propulsive effort of car load, specifically comprise the steps:

According to calculating effective output torque T of the front axle mouth obtaining in tire radius r, step SA _frtAx, and effective output torque T of rear axle mouth _rrAx, by following expression, 10. calculate and obtain the effective propulsive effort F of described car load _drive:

F _Drive=F _FrtAx+F _RrAx=T _FrtAx/r+T _RrAx/r ⑩

Wherein, F _frtAxfor the effective propulsive effort of front axle, F _rrAxfor the effective propulsive effort of rear axle.This expression formula is expresses the effective propulsive effort F of car load _driveby obtaining after the effective propulsive effort of front axle and the effective propulsive effort stack of rear axle.

SC, obtain whole vehicle resistance F _res, specifically comprise the steps:

Contriver has considered the variety of way of vehicle drag in R&D process, and vehicle drag comprises air resistance, rolling resistance, resistance due to acceleration, cornering resistance, gradient resistance etc.Wherein cornering resistance, due to less, is ignored.

According to expression formula obtain resistance due to acceleration F _acc;

Before mention, contriver finds air resistance F _air, rolling resistance F _rollthese two resistances are only relevant with speed with the structure of vehicle, therefore by air resistance F _air, rolling resistance F _rollmerging is as the resistance of taxing F of vehicle _c, by Coast-down check, obtain described resistance of taxing F _c;

Described car load resistance F _respass through following expression realize:

F _Res=F _Air+F _Roll+F _Acc+F _Slope

Described car load resistance F _rescan be rewritten as following expression

F _Res=F _C+F _Acc+F _Slope

SD, according to Newton's second law, derive gradient resistance F _slope, specifically comprise the steps:

The effective propulsive effort F of car load obtaining according to step SB _drive, and step SC in obtain whole vehicle resistance F _res;

According to Newton's second law, known:

∑F=F _Drive-F _Res=0

Therefore described gradient resistance F _slopecan realize by following expression:

F _Slope=F _Drive-F _C+F _Acc。

8., 9., 10. bring expression formula in abovementioned steps into expression formula in, can obtain expression formula 7.:

$F_{\mathrm{Slope}}=[T_{\mathrm{EMS}}+T_{\mathrm{ISG}}-(J_{\mathrm{EMS}}+J_{\mathrm{ISG}}){\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{EMS}}]n_1/r-J_{\mathrm{Tyer}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{Tyer}}/r$

$+(T_{\mathrm{ERAD}}-J_{\mathrm{ERAD}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{ERAD}})n_2/r$ ⑦

$-F_C-F_{\mathrm{Acc}}$

Be more than the thinking based on effective propulsive effort, when calculating effective propulsive effort of front driving axle and rear driving axle, in advance the propulsive effort of front driving axle deducted to the inertia resistance that corresponding rotatable parts bring, and then obtain effective propulsive effort of front driving axle; Can the propulsive effort of rear driving axle be deducted to the inertia resistance that corresponding rotatable parts bring by same method, and then obtain effective propulsive effort of rear driving axle; Synthesized the effective propulsive effort of car load, other resistances of outside (being resistance of taxing and resistance due to acceleration) that the effective propulsive effort of car load deducted to vehicle obtain gradient resistance again.

Equally, as another kind derivation mode, can first calculate the propulsive effort of front driving axle and rear driving axle, both are synthesized to car load propulsive effort (non-effective propulsive effort, it does not deduct the inertia resistance that each rotatable parts are brought into), more other resistances of outside that car load propulsive effort deducts car load inertia resistance and vehicle are obtained to gradient resistance.This kind of thinking is that the inertia resistance that in vehicle, each rotatable parts bring is merged as a total parameter, no matter adopts which kind of mode to derive, and its net result is identical, repeats no more.

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any modifications of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., within all should being included in protection scope of the present invention.

Claims (10)

1. a hybrid vehicle gradient resistance acquisition methods, described hybrid vehicle comprises driving engine, ISG motor, rear motor, front gear box, rear speed-changing mechanism, front driving axle and rear driving axle; The output shaft of described driving engine connects described front driving axle at the described ISG motor of connection by described front gear box, and described rear motor speed-changing mechanism after described connects described rear driving axle; It is characterized in that, described hybrid vehicle gradient resistance acquisition methods comprises the steps:

Obtain the speed ratio n of described front gear box ₁, described rear speed-changing mechanism speed ratio n ₂, tire radius r and complete vehicle quality m;

By measuring and calculating, obtain the output torque T of described driving engine _eMS, described ISG motor output torque T _iSGoutput torque T with described rear motor _eRAD;

Coast-down check by vehicle obtains resistance of taxing F _c;

By the speed of a motor vehicle difference of vehicle, obtained the car load acceleration/accel of vehicle then pass through expression formula obtain car load resistance due to acceleration F _acc;

According to the rotor inertia of rotatable parts on vehicle and angular acceleration, obtain car load inertia resistance F _j;

According to the parameter of above-mentioned acquisition, adopt following expression formula estimation to obtain gradient resistance F _slope:

F _Slope=[T _EMS+T _ISG]n ₁/r+T _ERAD·n ₂/r-F _C-F _Acc-F _j。

2. hybrid vehicle gradient resistance acquisition methods according to claim 1, is characterized in that, described according to the rotor inertia of rotatable parts on vehicle and angular acceleration acquisition car load inertia resistance F _jspecifically comprise the steps:

According to rotor inertia corresponding to described front driving axle and angular acceleration estimation, obtain front driving axle inertia resistance F _jf, according to rotor inertia corresponding to described rear driving axle and angular acceleration estimation, obtain rear driving axle inertia resistance F _jr, according to rotor inertia corresponding to tire end and angular acceleration, estimation obtains the inertia resistance F of tire _jt;

By described front driving axle inertia resistance F _jf, described rear driving axle inertia resistance F _jrand the inertia resistance F of described tire _jtsummation obtains described car load inertia resistance F _j.

3. hybrid vehicle gradient resistance acquisition methods according to claim 2, is characterized in that, described front driving axle inertia resistance F _jfobtain as follows:

Measuring and calculating obtains engine output shaft angular acceleration the rotor inertia J of engine crankshaft _eMSand the rotor inertia J of ISG rotor _iSG;

According to following expression, obtain described front driving axle inertia resistance F _jf:

$F_{\mathrm{jf}}=(J_{\mathrm{EMS}}+J_{\mathrm{ISG}}){\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{EMS}}\·n_1/r.$

4. hybrid vehicle gradient resistance acquisition methods according to claim 2, is characterized in that, described rear driving axle inertia resistance F _jrobtain as follows:

Measuring and calculating obtains rear motor angular acceleration with the total rotor inertia J of rear axle _eRAD;

By following expression, obtain described rear driving axle inertia resistance F _jr:

$F_{\mathrm{jr}}=J_{\mathrm{ERAD}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{ERAD}}\·n_2/r.$

5. hybrid vehicle gradient resistance acquisition methods according to claim 2, is characterized in that, the inertia resistance F of described tire _jtobtain as follows;

Measuring and calculating obtains the rotor inertia J for tire and change speed gear box _tyerwith tire angular acceleration

By following expression, estimate the inertia resistance F that obtains described tire _jt:

$F_{\mathrm{jt}}=J_{\mathrm{Tyer}}{\stackrel{\·}{\mathrm{\ω}}}_{\mathrm{Tyer}}/r.$

6. hybrid vehicle gradient resistance acquisition methods according to claim 1, is characterized in that, the output torque T of described acquisition driving engine _eMSconcrete steps be:

According to the aperture of throttle gate, calculate the numerical value of suction quantity;

According to the moment calculating timing of ignition of ignition angle;

According to the aperture of described throttle gate and described timing of ignition, table look-up and draw the output torque T of driving engine _eMS.

7. hybrid vehicle gradient resistance acquisition methods according to claim 1, is characterized in that, described rear motor angular acceleration by following estimation steps, obtain:

The rear motor tach signal that described rear motor is come by bus transfer converts angular velocity signal to;

Described angular velocity signal is carried out to single order LPF, to remove the interfere information of bringing in sampling process;

The described angular velocity signal differentiate of removing after interfere information is obtained to angular acceleration signal;

Described angular acceleration signal is carried out to single order LPF to get rid of due to fluctuating widely that calculating causes, thereby obtain described rear motor angular acceleration

8. hybrid vehicle gradient resistance acquisition methods according to claim 1, is characterized in that, described engine output shaft angular acceleration by following estimation steps, obtain:

The engine rotational speed signal that described driving engine is come by bus transfer converts angular velocity signal to;

Described angular velocity signal is carried out to single order LPF, to get rid of due to the interfere information of bringing in sampling process;

The described angular velocity signal differentiate of removing after interfere information is obtained to angular acceleration signal;

Described angular acceleration signal is carried out to single order LPF to get rid of due to fluctuating widely that calculating causes, thereby obtain described engine output shaft angular acceleration

9. hybrid vehicle gradient resistance acquisition methods according to claim 1, is characterized in that, described tire angular acceleration by following estimation steps, obtain:

The tire rotational speed signal that brake controller is come by bus transfer becomes angular velocity signal;

Described angular velocity signal is carried out to single order LPF, to remove due to the interfere information of bringing in sampling process;

The described angular velocity signal differentiate of removing after interfere information is obtained to angular acceleration signal;

Described angular acceleration signal is carried out to single order LPF to get rid of due to fluctuating widely that calculating causes, thereby obtain described tire angular acceleration

10. hybrid vehicle gradient resistance acquisition methods according to claim 1, is characterized in that, described whole vehicle acceleration/accel by following estimation steps, obtain:

The vehicle speed signal that brake controller is come by bus transfer is carried out single order LPF, to get rid of due to the interfere information of bringing in sampling process;

Described vehicle speed signal differentiate after removal interfere information is obtained to the acceleration signal of vehicle;

Described acceleration signal is carried out to single order LPF to get rid of due to fluctuating widely that calculating causes, thereby obtain described whole vehicle acceleration/accel