CN107117203A

CN107117203A - A kind of poor square servo steering system and its control method for automobile drive axle

Info

Publication number: CN107117203A
Application number: CN201710287637.7A
Authority: CN
Inventors: 陈龙; 仵晓涵; 徐兴; 王峰; 江昕炜
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2017-04-27
Filing date: 2017-04-27
Publication date: 2017-09-01
Anticipated expiration: 2037-04-27
Also published as: CN107117203B

Abstract

The invention discloses a kind of poor square servo steering system and its control method for automobile drive axle, testing agency's collection steering wheel angle information, steering-wheel torque information, wheel speed information, battery voltage information and battery current information, and transmit information to electronic control unit；Mode of operation selecting unit selects the different mode of operation of poor square servo steering system for driver, and operating mode information is sent into electronic control unit；Electronic control unit controls switching and electromagnetic clutch, stand-by motor and the brake operation of executing agency of mode of operation according to the information received, utilize the brake on the stand-by motor and left and right sides driving moment being connected with drive axle or so semiaxis, make left and right sides driving moment that there are different driving moments or braking moment, and vehicle is produced the yaw moment that an auxiliary driver turns to, so as to reduce the power of driver's application on the steering wheel, poor square power-assisted steering is realized, and preferably steering feel is provided for driver.

Description

A kind of poor square servo steering system and its control method for automobile drive axle

Technical field

The invention belongs to automobile technical field, be especially a kind of poor square servo steering system for automobile drive axle and Its control method.

Background technology

Automobile steering system is a set of specialized organization for being used for changing or recovering vehicle traveling direction, and it is to ensure vapour that it, which is acted on, Car can carry out Turning travel according to the will of driver, and the performance of automobile steering system will directly influence the manipulation of vehicle Stability and security.The steering behaviour of automobile is generally improved using servo steering system at present, servo steering system is a set of Dual-purpose driver muscle power and the steering that extrinsic power is steerable energy, are the requirements in order to meet people to driving portability And produce.When driver operates Vehicular turn, in the presence of servo steering system, driver only needs to apply steering wheel Plus less power, it becomes possible to vehicle is completed steering.It is simpler and light that servo steering system makes that driving becomes, and allows car Reaction is quicker, while also improving the security of vehicle to a certain extent.

Now common servo steering system mainly has mechanical hydraulic power-assist steering system, electronic hydraulic power-assisted steering system And electric boosting steering system, these servo steering systems are required for being used as power source using engine without exception.Mechanical-hydraulic The assist characteristic of servo steering system can not be adjusted, and no matter whether vehicle turns to its oil pump is in working condition, energy consumption compared with It is high；Electronic hydraulic power-assisted steering system sets up electronic-controlled installation on the basis of mechanical-hydraulic servo steering system, passes through electricity Motivation drives oil pump, reduces energy consumption, it is possible to realize the regulation to assist characteristic, while when meeting vehicle high-speed and low speed Power-assisted requirement, but the shortcoming of hydraulic power-assist steering system still can not be thoroughly solved, and because turn in original hydraulic booster Electronic control system is added on to system, makes its structure more complicated；Electric boosting steering system is directly provided by motor Power steering, and motor only works in Vehicular turn, reduces energy expenditure, electric boosting steering system can also improve The power steering characteristic of vehicle, and there is few part, light weight, compact conformation and be easy to matching.

The content of the invention

The purpose of the present invention is to propose to a kind of poor square servo steering system and its control method for automobile drive axle, when During driver turn steering wheel, the system on the stand-by motor and left and right sides driving moment being connected with drive axle or so semiaxis is utilized Dynamic device, makes left and right sides driving moment have different driving moments or braking moment, and vehicle is produced an auxiliary driving The yaw moment that member turns to, so as to reduce the power of driver's application on the steering wheel, realizes poor square power-assisted steering, and be driver There is provided and preferably turn to feel.The present invention have the advantages that it is similar to above-mentioned electric boosting steering system, while can be further The energy consumption of servo steering system is reduced, makes vehicle that there is more preferable security, comfortableness, control stability and dynamic property, and have More expanded functions are realized in prestige.

The technical solution adopted in the present invention is a kind of poor square servo steering system for automobile drive axle, main bag Include：Executing agency, testing agency, mode of operation selecting unit and electronic control unit.

The poor square servo steering system can be used for the front driving axle of forerunner's automobile or the rear driving axle of engine rear-drive automobile, if For the front driving axle of forerunner's automobile, should ensure that vehicle front-wheel scrub radius be on the occasion of；

The executing agency includes stand-by motor, motor gear, electromagnetic clutch, axle shaft gear, battery and brake；Institute State the motor gear and the axle shaft gear and drive axle that stand-by motor passes through the electromagnetic clutch and a pair of meshing Semiaxis is connected；The stand-by motor can not only be used as generator but also can be used as motor；It is auxiliary that the stand-by motor includes first Help motor and the second stand-by motor；The structure formed objects of first stand-by motor and second stand-by motor are equal；Institute Stating the first stand-by motor is used to provide the moment of resistance and driving moment for the left half axle of drive axle；Second stand-by motor is used for The right axle shaft of drive axle provides the moment of resistance and driving moment；The stand-by motor should ensure that, driver turn steering wheel, the difference When square servo steering system works, under most operating modes, the poor square servo steering system only controls the described of drive axle side The moment of resistance that stand-by motor is provided as generator operation makes the moment difference that both sides driving moment is produced, it is possible to achieve poor square is helped Power is turned to, and provides preferably steering feel for driver；The motor gear includes the first motor gear and the second motor tooth Wheel；The structure formed objects of first motor gear and second motor gear are equal；The electromagnetic clutch includes the One electromagnetic clutch and the second electromagnetic clutch；First electromagnetic clutch is identical with the structure of second electromagnetic clutch It is equal in magnitude；Described first electromagnetic clutch one end is connected with the rotating shaft of first stand-by motor, the other end and described first Motor gear is connected；Described second electromagnetic clutch one end is connected with the rotating shaft of second stand-by motor, the other end with it is described Second motor gear is connected；The electromagnetic clutch is used for, when speed exceedes speed setting value (such as speed ＞ 60km/h), i.e., When the poor square servo steering system need not provide power steering for driver, the stand-by motor and the motor tooth are cut off Power transmission between wheel, it is to avoid the stand-by motor fast idle；The original state of the electromagnetic clutch is engagement state；Institute Stating axle shaft gear includes the first axle shaft gear and the second axle shaft gear；First axle shaft gear and second axle shaft gear Structure formed objects are equal；First axle shaft gear is arranged on the left half axle of drive axle；First axle shaft gear and institute State the engagement of the first motor gear；Second axle shaft gear is arranged on the right axle shaft of drive axle；Second axle shaft gear with The second motor gear engagement；The battery is used to store the electric energy that the stand-by motor is sent, and is the stand-by motor Electric energy is provided；The brake includes the first brake and second brake；First brake and the second brake Structure formed objects it is equal；First brake is the brake in drive axle left side wheel；The second brake is Brake in drive axle right side wheels；The brake is used for, under a small number of operating modes, and the poor square servo steering system is only controlled The moment of resistance that the stand-by motor of drive axle side processed is provided as generator operation makes the torque that both sides driving moment is produced Difference, it is impossible to when realizing poor square power-assisted steering or preferably steering feel can not be provided for driver, coordinate the stand-by motor Work, applies certain brake force to single wheel, to increase the moment difference of both sides driving moment；

The testing agency includes steering wheel angle sensor, steering-wheel torque sensor, speed probe, voltage sensor Device and current sensor；The steering wheel angle sensor is arranged in the steering spindle of steering, is turned for measuring steering wheel The size and Orientation at angle, and by steering wheel angle information transmission to the electronic control unit；The steering-wheel torque sensor In the steering spindle of steering, the size and Orientation for measuring torque in steering spindle, i.e. driver act on steering The size and Orientation of torque on disk, and by steering-wheel torque information transmission to the electronic control unit；The revolution speed sensing Device includes the first speed probe, the second speed probe, the 3rd speed probe and the 4th speed probe；Described first turn Fast sensor, second speed probe, the 3rd speed probe and the 4th speed probe are respectively used to survey Amount left side driving moment, right side driving moment, the rotating speed of left side non-driven wheel and right side non-driven wheel, and by wheel speed information It is sent to the electronic control unit；The voltage sensor is used for the terminal voltage for measuring the battery, and cell voltage is believed Breath is sent to the electronic control unit；The current sensor is used to measuring the charging and discharging currents of the battery, and by battery Current information is sent to the electronic control unit；

The mode of operation selecting unit is used to select the different Working mould of the poor square servo steering system for driver Formula, and operating mode information is sent to the electronic control unit, the electronic control unit is by according to different Working moulds Formula is adjusted to the control strategy of the poor square servo steering system；The mode of operation includes four kinds of patterns：Energy saver mode, Balanced mode, performance mode and automatic mode；When the poor square servo steering system is the energy saver mode, the electronics control Unit processed will pay the utmost attention to make the stand-by motor of drive axle side as generator operation, while the auxiliary of opposite side Motor dallies, and moment of resistance when being generated electricity using the stand-by motor makes both sides driving moment have different driving moment or braking Torque, realizes poor square power-assisted steering, and provides preferably steering feel for driver, if only controlling the described of drive axle side The moment of resistance that stand-by motor is provided as generator operation makes the moment difference that both sides driving moment is produced, it is impossible to realize that poor square is helped Power, which is turned to or can not provided for driver, preferably turns to feel, then controls the brake to coordinate the stand-by motor work, Apply certain brake force to wheel using brake described in side, to increase the moment difference of both sides driving moment, now make It is first moment of resistance to the moment of resistance that semiaxis applies for the stand-by motor of generator operation；First moment of resistance is described The maximum resistance square that stand-by motor can be provided under current working；When the poor square servo steering system is the balanced mode When, the electronic control unit will control the stand-by motor of drive axle side as generator operation, while control is another The stand-by motor of side is as electric motor operation, described in the moment of resistance and opposite side when being generated electricity using stand-by motor described in side The driving moment that stand-by motor is provided, makes both sides driving moment have different driving moments or braking moment, realizes that poor square is helped Power is turned to, and provides preferably steering feel for driver, and now semiaxis is applied as the stand-by motor of generator operation Plus the moment of resistance and the driving moment approximately equal that applies to semiaxis of the stand-by motor as electric motor operation；When the difference When square servo steering system is the performance mode, the electronic control unit will be paid the utmost attention to make the described auxiliary of drive axle side Motor is helped as electric motor operation, while the stand-by motor idle running of opposite side, the driving provided using the stand-by motor Torque makes both sides driving moment have different driving moments, realizes poor square power-assisted steering, and provide preferable turn for driver To feel, if the driving moment that the stand-by motor of only control drive axle side is provided as electric motor operation drives both sides The driving moment difference that motor car wheel is produced, it is impossible to realize poor square power-assisted steering or preferably steering hand can not be provided for driver Sense, then the stand-by motor for controlling drive axle opposite side coordinate as generator operation and are used as the described auxiliary of electric motor operation Motor is helped, applies certain moment of resistance to opposite side semiaxis, to increase the moment difference of both sides driving moment, now as electronic The driving moment that the stand-by motor of machine work applies to semiaxis is First Driving Force square；The First Driving Force square is described The maximum drive torque that stand-by motor can be provided under current working；When the poor square servo steering system is the automatic mold During formula, the electronic control unit will consider the information received, control the stand-by motor and the brake operation, On the premise of ensureing that the poor square servo steering system is energy-efficient, there is vehicle and preferably turn to feel, and improve car Security, comfortableness, control stability and dynamic property, while making the SOC of the battery maintain a rational scope Interior (such as 40% ＜ SOC ＜ 70%)；The default mode of the poor square servo steering system is the automatic mode；When the poor square When servo steering system is the balanced mode or the performance mode, if the SOC of the battery is less than SOC setting values (such as SOC ＜ 20%), the electronic control unit will intervene the mode of operation, and be switched to the automatic mode；

The electronic control unit includes input module, computing module, mode of operation control module, electromagnetic clutch control Module, stand-by motor control module, brake control module and output module；The electronic control unit is according to the Working mould Formula information, the steering wheel angle information, the steering-wheel torque information, the wheel speed information, the battery voltage information and The battery current information controls the switching and the electromagnetic clutch, the stand-by motor and the braking of the mode of operation Device works, and left and right sides driving moment is had different driving moments or braking moment, realizes poor square power-assisted steering, and to drive The person of sailing, which provides, preferably turns to feel；The input module receives the operating mode information, the steering wheel angle information, institute State steering-wheel torque information, the wheel speed information, the battery voltage information and the battery current information, and by information transmission To the computing module；The computing module generates battery according to the battery voltage information and the battery current information first SOC information；And according to the battery SOC information, judge whether the SOC of the battery is less than SOC setting values (such as SOC ＜ 20%)；Secondly current vehicle speed, the first stand-by motor rotating speed and the second stand-by motor rotating speed are calculated according to the wheel speed information； And according to the speed, judge whether current vehicle speed is equal to zero；If current vehicle speed is not equal to zero, judge whether current vehicle speed surpasses Cross speed setting value (such as speed ＞ 60km/h)；Again according to the steering wheel angle information, the steering-wheel torque information, institute Wheel speed information and the speed are stated, the target moment difference of left and right wheelses is calculated；Finally according to the operating mode information, institute State steering wheel angle information, the steering-wheel torque information, the wheel speed information, the battery voltage information, battery electricity Stream information, the battery SOC information, the speed, the first stand-by motor rotating speed, the second stand-by motor rotating speed and institute Target moment difference is stated, first stand-by motor and the moment of resistance or driving moment of second stand-by motor and institute is calculated State the braking moment of the first brake and the second brake；Result of determination and result of calculation are sent to by the computing module The mode of operation control module, the electromagnetic clutch control module, the stand-by motor control module and the brake Control module；When for the energy saver mode, the computing module will calculate first stand-by motor or described second auxiliary Help first moment of resistance of motor；First moment of resistance is the maximum resistance that the stand-by motor can be provided under current working Square；And judge whether to need the brake operation, that is, judge whether the target moment difference is more than first moment of resistance； If desired the brake operation, i.e., described target moment difference is more than first moment of resistance, now only controls drive axle one The moment of resistance that the stand-by motor of side is provided as generator operation can not make the moment difference of both sides driving moment be equal to institute Target moment difference is stated, the computing module will calculate the braking moment of first brake or the second brake； If not needing the brake operation, i.e., described target moment difference is less than or equal to first moment of resistance, and now only control is driven The moment of resistance that the stand-by motor of dynamic bridge side is provided as generator operation can make the moment difference of both sides driving moment Equal to the target moment difference, the computing module will calculate first stand-by motor or second stand-by motor The moment of resistance；When for the balanced mode, the stand-by motor of drive axle both sides works simultaneously, and stand-by motor described in side is made For generator operation, while stand-by motor described in opposite side is as electric motor operation, and the auxiliary of generator operation is used as The moment of resistance that motor applies to semiaxis is approximate with the driving moment that the stand-by motor as electric motor operation applies to semiaxis Equal, the computing module will calculate the moment of resistance or driving force of first stand-by motor and second stand-by motor Square；When for the performance mode, the computing module will calculate first stand-by motor or second stand-by motor First Driving Force square；The First Driving Force square is the maximum driving force that the stand-by motor can be provided under current working Square；And judge whether to need stand-by motor described in both sides to work simultaneously, that is, judge whether the target moment difference is more than described First Driving Force square；If desired stand-by motor described in both sides works simultaneously, i.e., described target moment difference is more than described first and driven Kinetic moment, the driving moment that now stand-by motor of only control drive axle side is provided as electric motor operation can not make two The moment difference of side driving moment is equal to the target moment difference, and the computing module, which will be calculated, aids in electricity described in opposite side The moment of resistance of machine；If do not need stand-by motor described in both sides to work simultaneously, i.e., described target moment difference is less than or equal to described the One driving moment, the driving moment that now only the stand-by motor of control drive axle side is provided as electric motor operation can be with The moment difference of both sides driving moment is set to be equal to the target moment difference, the computing module will calculate first auxiliary The driving moment of motor or second stand-by motor；When for the automatic mode, the computing module, which will consider, to be connect The information received, calculates first stand-by motor and the moment of resistance or driving moment of second stand-by motor and described The braking moment of one brake and the second brake, is ensureing the energy-efficient premise of the poor square servo steering system Under, there is vehicle and preferably turn to feel, and security, comfortableness, control stability and the dynamic property of vehicle are improved, simultaneously The SOC of the battery is set to maintain in a rational scope (such as 40% ＜ SOC ＜ 70%)；The mode of operation control module According to the result of determination and result of calculation generation mode of operation control instruction, and control instruction is sent to the output mould Block, is the balanced mode or the performance mode in the poor square servo steering system, and the SOC of the battery is less than SOC During setting value (such as SOC ＜ 20%), the poor square servo steering system is switched into the automatic mode；The electromagnetic clutch Control module generates the first electromagnetic clutch control instruction and the second electromagnetic clutch according to the result of determination and result of calculation Control instruction, and control instruction is sent to the output module；The stand-by motor control module is according to the result of determination The first stand-by motor control instruction and the second stand-by motor control instruction are generated with result of calculation, and control instruction is sent to institute State output module；The brake control module generates the first brake control instruction according to the result of determination and result of calculation With second brake control instruction, and control instruction is sent to the output module；The output module and the Working mould It is formula selecting unit, first electromagnetic clutch, second electromagnetic clutch, first stand-by motor, described second auxiliary Help motor and ABS control unit to connect, and mode of operation control instruction, electromagnetic clutch control instruction and stand-by motor are controlled Instruction is sent to target device, and brake control instruction is sent to ABS control unit, passes through ABS by the work of control targe equipment Control unit controls the brake operation.

The present invention provides a kind of control method of poor square servo steering system for automobile drive axle, and described poor square is helped Power steering includes four kinds of mode of operations：Energy saver mode, balanced mode, performance mode and automatic mode；

The energy saver mode comprises the following steps：

Step 101, according to the speed, judge whether current vehicle speed is equal to zero；

Step 102, if current vehicle speed is not equal to zero, judge whether current vehicle speed exceedes speed setting value (such as speed ＞ 60km/h)；

Step 103, if current vehicle speed is not above speed setting value, the electromagnetic clutch engagement；

Step 104, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and described Speed, calculates the target moment difference of left and right wheelses；

Step 105, according to the wheel speed information, the battery voltage information, the battery current information, the battery SOC information, the first stand-by motor rotating speed and the second stand-by motor rotating speed, calculate first stand-by motor or institute State first moment of resistance of the second stand-by motor；First moment of resistance stand-by motor can be provided under current working Maximum resistance square；

Step 106, judge whether to need the brake operation, that is, judge whether the target moment difference is more than described First moment of resistance；

Step 107, if necessary to the brake operation, i.e., described target moment difference is more than first moment of resistance, The moment of resistance that now stand-by motor of only control drive axle side is provided as generator operation can not make both sides drive car The moment difference of wheel is equal to the target moment difference, then calculates the braking of first brake or the second brake Torque；

Step 108, the stand-by motor is as generator operation, while the brake, realizes that poor square power-assisted turns To, and preferably steering feel is provided for driver, the moment of resistance that now stand-by motor applies to semiaxis is described first The moment of resistance；

Step 109, if not needing the brake operation, i.e., described target moment difference is less than or equal to the described first resistance Torque, the moment of resistance that now stand-by motor of only control drive axle side is provided as generator operation can drive both sides The moment difference of motor car wheel is equal to the target moment difference, then calculates first stand-by motor or the second auxiliary electricity The moment of resistance of machine；

Step 110, the stand-by motor is as generator operation, realizes poor square power-assisted steering, and for driver provide compared with Good steering feel；

Step 111, if current vehicle speed exceedes speed setting value, the electromagnetic clutch separation, it is to avoid the auxiliary Motor fast idle；

Step 112, if current vehicle speed is equal to zero, judge whether the poor square servo steering system powers off；

Step 113, if the poor square servo steering system is not powered off, the stand-by motor is stopped, simultaneously The brake release；

The balanced mode comprises the following steps：

Step 201, according to the speed, judge whether current vehicle speed is equal to zero；

Step 202, if current vehicle speed is not equal to zero, judge whether current vehicle speed exceedes speed setting value (such as speed ＞ 60km/h)；

Step 203, if current vehicle speed is not above speed setting value, the electromagnetic clutch engagement；

Step 204, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and described Speed, calculates the target moment difference of left and right wheelses；

Step 205, the moment of resistance or driving moment of first stand-by motor and second stand-by motor are calculated, and The moment of resistance and driving moment approximately equal；

Step 206, the stand-by motor of both sides works simultaneously, and stand-by motor described in side is as generator operation, together When stand-by motor described in opposite side as electric motor operation, apply the moment of resistance and driving moment respectively to both sides semiaxis, it is poor to realize Square power-assisted steering, and provide preferably steering feel for driver；

Step 207, if current vehicle speed exceedes speed setting value, the electromagnetic clutch separation, it is to avoid the auxiliary Motor fast idle；

Step 208, if current vehicle speed is equal to zero, judge whether the poor square servo steering system powers off；

Step 209, if the poor square servo steering system is not powered off, the stand-by motor is stopped；

The performance mode comprises the following steps：

Step 301, according to the speed, judge whether current vehicle speed is equal to zero；

Step 302, if current vehicle speed is not equal to zero, judge whether current vehicle speed exceedes speed setting value (such as speed ＞ 60km/h)；

Step 303, if current vehicle speed is not above speed setting value, the electromagnetic clutch engagement；

Step 304, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and described Speed, calculates the target moment difference of left and right wheelses；

Step 305, according to the wheel speed information, the battery voltage information, the battery current information, the battery SOC information, the first stand-by motor rotating speed and the second stand-by motor rotating speed, calculate first stand-by motor or institute State the First Driving Force square of the second stand-by motor；The First Driving Force square can carry for the stand-by motor under current working The maximum drive torque of confession；

Step 306, judge whether to need stand-by motor described in both sides to work simultaneously, that is, judge that the target moment difference is It is no to be more than the First Driving Force square；

Step 307, work simultaneously if necessary to stand-by motor described in both sides, i.e., described target moment difference is more than described the One driving moment, the driving moment that now stand-by motor of only control drive axle side is provided as electric motor operation can not The moment difference of both sides driving moment is equal to the target moment difference, then calculate the resistance of stand-by motor described in opposite side Square；

Step 308, the stand-by motor of both sides works simultaneously, and stand-by motor described in side is as generator operation, together When stand-by motor described in opposite side as electric motor operation, apply the moment of resistance and driving moment respectively to both sides semiaxis, it is poor to realize Square power-assisted steering, and provide preferably steering feel, the driving moment that now stand-by motor applies to semiaxis for driver For the First Driving Force square；

Step 309, if do not need stand-by motor described in both sides to work simultaneously, i.e., described target moment difference is less than or equal to The First Driving Force square, the driving force that now stand-by motor of only control drive axle side is provided as electric motor operation Square can make both sides driving moment moment difference be equal to the target moment difference, then calculate first stand-by motor or The driving moment of second stand-by motor；

Step 310, the stand-by motor is as electric motor operation, realizes poor square power-assisted steering, and for driver provide compared with Good steering feel；

Step 311, if current vehicle speed exceedes speed setting value, the electromagnetic clutch separation, it is to avoid the auxiliary Motor fast idle；

Step 312, if current vehicle speed is equal to zero, judge whether the poor square servo steering system powers off；

Step 313, if the poor square servo steering system is not powered off, the stand-by motor is stopped；

The automatic mode comprises the following steps：

Step 401, according to the speed, judge whether current vehicle speed is equal to zero；

Step 402, if current vehicle speed is not equal to zero, judge whether current vehicle speed exceedes speed setting value (such as speed ＞ 60km/h)；

Step 403, if current vehicle speed is not above speed setting value, the electromagnetic clutch engagement；

Step 404, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and described Speed, calculates the target moment difference of left and right wheelses；

Step 405, calculate first stand-by motor and second stand-by motor the moment of resistance or driving moment and The braking moment of first brake and the second brake, result of calculation should ensure that the security, comfortableness, behaviour of vehicle Handing stability and dynamic property；

Step 406, the stand-by motor work, the brake is ensureing that the poor square servo steering system is high On the premise of imitating energy-conservation, poor square power-assisted steering is realized, and preferably steering feel is provided for driver；

Step 407, if current vehicle speed exceedes speed setting value, the electromagnetic clutch separation, it is to avoid the auxiliary Motor fast idle；

Step 408, if current vehicle speed is equal to zero, judge whether the poor square servo steering system powers off；

Step 409, if the poor square servo steering system is not powered off, the stand-by motor is stopped, simultaneously The brake release.

The beneficial effects of the invention are as follows：

1) poor square servo steering system of the present invention utilizes the stand-by motor being connected with drive axle or so semiaxis and a left side Brake in right both sides driving moment, realizes the independent control to the driving moment or braking moment of left and right sides driving moment System.

2) poor square servo steering system of the present invention is by making left and right sides driving moment have different driving forces Square or braking moment, and vehicle is produced the yaw moment that an auxiliary driver turns to, turn so as to reduce driver and be applied to To the power on disk, realize poor square power-assisted steering, and provide preferable steering feel for driver, with electric power steering system The similar advantage of system, and be expected to realize lower energy consumption.

3) poor square servo steering system of the present invention has four kinds of mode of operations；It would generally turn in view of driver Curved preceding braking deceleration, in energy saver mode, stand-by motor realizes poor square power-assisted steering, improves vehicle as generator operation Security, and realize energy regenerating；Outboard wheels adhesive force increase during in view of turning, in balanced mode, turn inside diameter is interior Side stand-by motor is as generator operation, and outside stand-by motor realizes poor square power-assisted steering, and make vehicle as electric motor operation Total driving force it is constant, improve vehicle comfortableness, control stability and dynamic property, in performance mode, stand-by motor conduct Electric motor operation, realizes poor square power-assisted steering, and vehicle is had more preferable dynamic property；In automatic mode, according to vehicle peace Quan Xing, comfortableness, control stability and dynamic property calculate the moment of resistance and driving moment and the braking of brake of stand-by motor Torque.

4) poor square servo steering system of the present invention is expected to realize more expanded functions, such as when vehicle is braked, profit Generated electricity with stand-by motor, reduce the load of brakes, realized the recovery to braking energy, when vehicle accelerates, utilize auxiliary Motor provides certain driving force, improves the acceleration of vehicle, and reduces fuel consumption.

5) the original dynamical system of vehicle and the stand-by motor can be with poor square servo steering system of the present invention Driving moment is provided for wheel, and the poor square servo steering system has generating function, therefore, the present invention is in I. C. engine steam Application potential is respectively provided with car, hybrid vehicle and electric automobile.

Brief description of the drawings

Fig. 1 is the structural representation of the present invention；

Fig. 2 is the structural representation of control system in the present invention；

Fig. 3 is the step flow chart of energy saver mode in control method of the present invention；

Fig. 4 is the step flow chart of balanced mode in control method of the present invention；

Fig. 5 is the step flow chart of performance mode in control method of the present invention；

Fig. 6 is the step flow chart of automatic mode in control method of the present invention.

In figure, the 1, first stand-by motor；2nd, the second stand-by motor；3rd, the first electromagnetic clutch；4th, the second electromagnetic clutch； 5th, the first motor gear；6th, the second motor gear；7th, the first axle shaft gear；8th, the second axle shaft gear；9th, the first brake；10、 Second brake；11st, battery；12nd, semiaxis；13rd, wheel；14th, main reducing gear gear wheel；15th, differential mechanism；16th, Electronic Control list Member.

Embodiment

Embodiment is to a kind of poor square servo steering system for automobile drive axle of the invention below in conjunction with the accompanying drawings And its control method is described in further detail, but protection scope of the present invention is not limited to this.

The poor square servo steering system can be used for the front driving axle of forerunner's automobile or the rear driving axle of engine rear-drive automobile, if For the front driving axle of forerunner's automobile, should ensure that vehicle front-wheel scrub radius be on the occasion of.

As shown in figure 1, a kind of poor square servo steering system for automobile drive axle of the invention includes the first stand-by motor 1st, the second stand-by motor 2, the first electromagnetic clutch 3, the second electromagnetic clutch 4, the first motor gear 5, the second motor gear 6, First axle shaft gear 7, the second axle shaft gear 8, the first brake 9, second brake 10, battery 11, semiaxis 12, wheel 13, master Decelerator gear wheel 14, differential mechanism 15 and electronic control unit 16；The stand-by motor passes through the electromagnetic clutch and a pair The motor gear of engagement and the semiaxis 12 of the axle shaft gear and drive axle are connected；The stand-by motor can both be used as hair Motor can be used as motor again；The stand-by motor includes the first stand-by motor 1 and the second stand-by motor 2；Described first is auxiliary Help motor 1 equal with the structure formed objects of second stand-by motor 2；First stand-by motor 1 is used for for drive axle Left half axle 12 provides the moment of resistance and driving moment；Second stand-by motor 2 is used to provide resistance for the right axle shaft 12 of drive axle Square and driving moment；The stand-by motor should ensure that, driver turn steering wheel, during the poor square servo steering system work, Under most operating modes, the poor square servo steering system only controls the stand-by motor of drive axle side as generator operation The moment of resistance of offer makes the moment difference that both sides driving moment 13 is produced, it is possible to achieve poor square power-assisted steering, and is carried for driver For preferably turning to feel；The electromagnetic clutch includes the first electromagnetic clutch 3 and the second electromagnetic clutch 4；Described first Electromagnetic clutch 3 is equal with the structure formed objects of second electromagnetic clutch 4；Described one end of first electromagnetic clutch 3 with The rotating shaft connection of first stand-by motor 1, the other end is connected with first motor gear 5；Second electromagnetic clutch 4 One end is connected with the rotating shaft of second stand-by motor 2, and the other end is connected with second motor gear 6；The electromagnetic clutch Device is used for, and when speed exceedes speed setting value (such as speed ＞ 60km/h), i.e., described poor square servo steering system need not be When driver provides power steering, the power cut off between the stand-by motor and the motor gear is transmitted, it is to avoid the auxiliary Motor fast idle；The original state of the electromagnetic clutch is engagement state；The motor gear includes the first motor gear 5 With the second motor gear 6；First motor gear 5 is equal with the structure formed objects of second motor gear 6；Described half Shaft gear includes the first axle shaft gear 7 and the second axle shaft gear 8；First axle shaft gear 7 and second axle shaft gear 8 Structure formed objects are equal；First axle shaft gear 7 is arranged on the left half axle 12 of drive axle；First axle shaft gear 7 Engaged with first motor gear 5；Second axle shaft gear 8 is arranged on the right axle shaft 12 of drive axle；Described the second half Shaft gear 8 is engaged with second motor gear 6；The brake includes the first brake 9 and second brake 10；Described One brake 9 is equal with the structure formed objects of the second brake 10；First brake 9 is drive axle left side wheel Brake on 13；The second brake 10 is the brake in drive axle right side wheels 13；The brake is used for, few Under number operating mode, the poor square servo steering system only controls the stand-by motor of drive axle side to be provided as generator operation The moment of resistance make the moment difference that both sides driving moment 13 is produced, it is impossible to realize poor square power-assisted steering or can not be provided for driver When preferably turning to feel, coordinate the stand-by motor work, apply certain brake force to single wheel 13, to increase both sides The moment difference of driving moment 13；The battery 11 is used to store the electric energy that the stand-by motor is sent, and is the auxiliary electricity Machine provides electric energy；The main reducing gear gear wheel 14 is fixedly connected with the housing of the differential mechanism 15, and by the output of engine Torque is delivered to the differential mechanism 15；The differential mechanism 15 is used to torque distributing to semiaxis 12 described in both sides；The electronics control Unit 16 processed according to the information that receives control the mode of operation switching and the electromagnetic clutch, the stand-by motor and The brake operation, realizes poor square power-assisted steering, and provide preferably steering feel for driver.

As shown in Fig. 2 control system of the present invention include testing agency, mode of operation selecting unit, electronic control unit 16, ABS control unit and executing agency；The testing agency includes steering wheel angle sensor, steering-wheel torque sensor, rotating speed Sensor, voltage sensor and current sensor；The steering wheel angle sensor is arranged in the steering spindle of steering, is used In the size and Orientation of measurement steering wheel angle, and by steering wheel angle information transmission to the electronic control unit 16；It is described Steering-wheel torque sensor is arranged in the steering spindle of steering, the size and Orientation for measuring torque in steering spindle, i.e., The size and Orientation of driver's effect torque on the steering wheel, and by steering-wheel torque information transmission to the Electronic Control list Member 16；The speed probe includes the first speed probe, the second speed probe, the 3rd speed probe and the 4th rotating speed Sensor；First speed probe, second speed probe, the 3rd speed probe and the 4th rotating speed Sensor is respectively used to measurement left side driving moment 13, right side driving moment 13, left side non-driven wheel 13 and right side non-driven The rotating speed of wheel 13, and by wheel speed information transmission to the electronic control unit 16；The voltage sensor is used to measure described The terminal voltage of battery 11, and battery voltage information is sent to the electronic control unit 16；The current sensor is used to survey Measure the charging and discharging currents of the battery 11, and by battery current information transmission to the electronic control unit 16；The Working mould Formula selecting unit is used to select the different mode of operation of the poor square servo steering system for driver, and by operating mode information Be sent to the electronic control unit 16, the electronic control unit 16 by according to different mode of operations to the poor square power-assisted The control strategy of steering is adjusted；The mode of operation includes four kinds of patterns：Energy saver mode, balanced mode, performance mould Formula and automatic mode；When the poor square servo steering system is the energy saver mode, the electronic control unit 16 will be preferential The stand-by motor for making drive axle side is considered as generator operation, while the stand-by motor idle running of opposite side, profit Moment of resistance when being generated electricity with the stand-by motor makes both sides driving moment 13 have different driving moment or braking moment, realizes Poor square power-assisted steering, and preferably steering feel is provided for driver, if the only stand-by motor of control drive axle side The moment of resistance provided as generator operation makes the moment difference that both sides driving moment 13 is produced, it is impossible to realize poor square power-assisted steering Or preferably steering feel can not be provided for driver, then control the brake to coordinate the stand-by motor work, utilize one Brake described in side applies certain brake force to wheel 13, to increase the moment difference of both sides driving moment 13, now conduct The moment of resistance that the stand-by motor of generator operation applies to semiaxis 12 is first moment of resistance；First moment of resistance is described The maximum resistance square that stand-by motor can be provided under current working；When the poor square servo steering system is the balanced mode When, the electronic control unit 16 will control the stand-by motor of drive axle side as generator operation, while control is another The stand-by motor of side is as electric motor operation, the moment of resistance and opposite side institute when being generated electricity using stand-by motor described in side The driving moment of stand-by motor offer is provided, makes both sides driving moment 13 that there is different driving moment or braking moment, it is poor to realize Square power-assisted steering, and for driver provide preferably turn to feel, now as generator operation the stand-by motor half-and-half The moment of resistance and the driving moment approximately equal that applies to semiaxis 12 of the stand-by motor as electric motor operation that axle 12 applies； When the poor square servo steering system is the performance mode, the electronic control unit 16 will be paid the utmost attention to make drive axle one The stand-by motor of side is as electric motor operation, while the stand-by motor idle running of opposite side, utilizes the stand-by motor The driving moment of offer makes both sides driving moment 13 have different driving moments, realizes poor square power-assisted steering, and be driver There is provided and preferably turn to feel, if the driving that the stand-by motor of only control drive axle side is provided as electric motor operation Torque makes the driving moment difference that both sides driving moment 13 is produced, it is impossible to realizes poor square power-assisted steering or can not be provided for driver Feel is preferably turned to, then the stand-by motor for controlling drive axle opposite side coordinates as generator operation and is used as motor The stand-by motor of work, applies certain moment of resistance to opposite side semiaxis 12, to increase the torque of both sides driving moment 13 Difference, the driving moment now applied as the stand-by motor of electric motor operation to semiaxis 12 is First Driving Force square；Institute It is the maximum drive torque that the stand-by motor can be provided under current working to state First Driving Force square；When the poor square power-assisted When steering is the automatic mode, the electronic control unit 16 will consider the information received, control described auxiliary Motor and the brake operation are helped, on the premise of ensureing that the poor square servo steering system is energy-efficient, there is vehicle Feel is preferably turned to, and improves security, comfortableness, control stability and the dynamic property of vehicle, while making the battery 11 SOC maintain in a rational scope (such as 40% ＜ SOC ＜ 70%)；The default mode of the poor square servo steering system For the automatic mode；When the poor square servo steering system is the balanced mode or the performance mode, if described The SOC of battery 11 is less than SOC setting values (such as SOC ＜ 20%), and the electronic control unit 16 will be carried out to the mode of operation Intervene, and be switched to the automatic mode；The electronic control unit 16 includes input module, computing module, Working mould Formula control module, electromagnetic clutch control module, stand-by motor control module, brake control module and output module；It is described Electronic control unit 16 is according to the operating mode information, the steering wheel angle information, the steering-wheel torque information, described Wheel speed information, the battery voltage information and the battery current information control the mode of operation switching and the electromagnetism from Clutch, the stand-by motor and the brake operation, make left and right sides driving moment 13 have different driving moment or system Kinetic moment, realizes poor square power-assisted steering, and provide preferably steering feel for driver；The input module receives the work Pattern information, the steering wheel angle information, the steering-wheel torque information, the wheel speed information, the battery voltage information With the battery current information, and the computing module is transmitted information to；The computing module is first according to battery electricity Press information and battery current information generation battery SOC information；And according to the battery SOC information, judge the battery 11 SOC whether be less than SOC setting values (such as SOC ＜ 20%)；Secondly current vehicle speed is calculated according to the wheel speed information, it is first auxiliary Help motor speed and the second stand-by motor rotating speed；And according to the speed, judge whether current vehicle speed is equal to zero；If current vehicle speed It is not equal to zero, then judges whether current vehicle speed exceedes speed setting value (such as speed ＞ 60km/h)；Again according to the steering wheel Corner information, the steering-wheel torque information, the wheel speed information and the speed, calculate the target torque of left and right wheelses 13 Difference；Finally according to the operating mode information, the steering wheel angle information, the steering-wheel torque information, the wheel speed Information, the battery voltage information, the battery current information, the battery SOC information, the speed, first auxiliary Motor speed, the second stand-by motor rotating speed and the target moment difference, calculate first stand-by motor 1 and described The moment of resistance or driving moment of second stand-by motor 2 and the braking moment of first brake 9 and the second brake 10； Result of determination and result of calculation are sent to the mode of operation control module, the electromagnetic clutch and controlled by the computing module Module, the stand-by motor control module and the brake control module；When for the energy saver mode, the computing module First moment of resistance of first stand-by motor 1 or second stand-by motor 2 will be calculated；First moment of resistance is described The maximum resistance square that stand-by motor can be provided under current working；And judge whether to need the brake operation, that is, judge Whether the target moment difference is more than first moment of resistance；If desired the brake operation, i.e., described target torque difference Value is more than first moment of resistance, the resistance that now stand-by motor of only control drive axle side is provided as generator operation Torque can not make the moment difference of both sides driving moment 13 be equal to the target moment difference, and the computing module will calculate institute State the braking moment of the first brake 9 or the second brake 10；If not needing the brake operation, i.e., described target force Square difference is less than or equal to first moment of resistance, and now the stand-by motor of only control drive axle side is used as generator operation The moment of resistance of offer can make the moment difference of both sides driving moment 13 be equal to the target moment difference, and the computing module will Calculate the moment of resistance of first stand-by motor 1 or second stand-by motor 2；When for the balanced mode, drive axle The stand-by motor of both sides works simultaneously, and stand-by motor described in side is as generator operation, while being aided in described in opposite side Motor the moment of resistance that applies to semiaxis 12 of the stand-by motor as generator operation and is used as electricity as electric motor operation The driving moment approximately equal that the stand-by motor of motivation work applies to semiaxis 12, the computing module will calculate described The moment of resistance or driving moment of first stand-by motor 1 and second stand-by motor 2；When for the performance mode, the fortune Calculate the First Driving Force square that module will calculate first stand-by motor 1 or second stand-by motor 2；First driving Torque is the maximum drive torque that the stand-by motor can be provided under current working；And judge whether to need auxiliary described in both sides Help motor to work simultaneously, that is, judge whether the target moment difference is more than the First Driving Force square；If desired described in both sides Stand-by motor works simultaneously, i.e., described target moment difference is more than the First Driving Force square, now only controls drive axle side The driving moment that is provided as electric motor operation of the stand-by motor can not be equal to the moment difference of both sides driving moment 13 The target moment difference, the computing module will calculate the moment of resistance of stand-by motor described in opposite side；If not needing both sides The stand-by motor is worked simultaneously, i.e., described target moment difference is less than or equal to the First Driving Force square, and now only control is driven The driving moment that the stand-by motor of dynamic bridge side is provided as electric motor operation can make the torque of both sides driving moment 13 Difference is equal to the target moment difference, and the computing module will calculate first stand-by motor 1 or second auxiliary The driving moment of motor 2；When for the automatic mode, the computing module will consider the information received, calculate The moment of resistance or driving moment and first brake 9 of first stand-by motor 1 and second stand-by motor 2 and described The braking moment of second brake 10, on the premise of ensureing that the poor square servo steering system is energy-efficient, has vehicle Feel is preferably turned to, and improves security, comfortableness, control stability and the dynamic property of vehicle, while making the battery 11 SOC maintain in a rational scope (such as 40% ＜ SOC ＜ 70%)；The mode of operation control module is sentenced according to Determine result and result of calculation generation mode of operation control instruction, and control instruction is sent to the output module, in the difference Square servo steering system is the balanced mode or the performance mode, and the SOC of the battery 11 is less than SOC setting values (such as SOC ＜ 20%) when, the poor square servo steering system is switched into the automatic mode；The electromagnetic clutch control module First electromagnetic clutch control instruction and the second electromagnetic clutch control instruction are generated according to the result of determination and result of calculation, And control instruction is sent to the output module；The stand-by motor control module is according to the result of determination and result of calculation The first stand-by motor control instruction and the second stand-by motor control instruction are generated, and control instruction is sent to the output mould Block；The brake control module generates the first brake control instruction and the second system according to the result of determination and result of calculation Dynamic device control instruction, and control instruction is sent to the output module；The output module selects single with the mode of operation First, described first electromagnetic clutch 3, second electromagnetic clutch 4, first stand-by motor 1, second stand-by motor 2 and ABS control unit connection, and by the mode of operation control instruction, the electromagnetic clutch control instruction and the auxiliary Motor control instruction is sent to target device, and the brake control instruction is sent to ABS controls by the work of control targe equipment Unit, the brake operation is controlled by ABS control unit.

The present invention provides a kind of control method of poor square servo steering system for automobile drive axle, and described poor square is helped Power steering includes four kinds of mode of operations：Energy saver mode, balanced mode, performance mode and automatic mode.

As described in Figure 3, in control method of the present invention energy saver mode step flow chart, comprise the following steps：

Step 104, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and described Speed, calculates the target moment difference of left and right wheelses 13；

Step 105, according to the wheel speed information, the battery voltage information, the battery current information, the battery SOC information, the first stand-by motor rotating speed and the second stand-by motor rotating speed, calculate first stand-by motor 1 or First moment of resistance of second stand-by motor 2；First moment of resistance can carry for the stand-by motor under current working The maximum resistance square of confession；

Step 107, if necessary to the brake operation, i.e., described target moment difference is more than first moment of resistance, The moment of resistance that now stand-by motor of only control drive axle side is provided as generator operation can not make both sides drive car The moment difference of wheel 13 is equal to the target moment difference, then calculates first brake 9 or the second brake 10 Braking moment；

Step 108, the stand-by motor is as generator operation, while the brake, realizes that poor square power-assisted turns To, and provided for driver and preferably turn to feel, the moment of resistance that now stand-by motor applies to semiaxis 12 is described the One moment of resistance；

Step 109, if not needing the brake operation, i.e., described target moment difference is less than or equal to the described first resistance Torque, the moment of resistance that now stand-by motor of only control drive axle side is provided as generator operation can drive both sides The moment difference of motor car wheel 13 is equal to the target moment difference, then calculates first stand-by motor 1 or described second auxiliary Help the moment of resistance of motor 2；

Step 113, if the poor square servo steering system is not powered off, the stand-by motor is stopped, simultaneously The brake release.

As described in Figure 4, in control method of the present invention balanced mode step flow chart, comprise the following steps：

Step 204, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and described Speed, calculates the target moment difference of left and right wheelses 13；

Step 205, the moment of resistance or driving moment of first stand-by motor 1 and second stand-by motor 2 are calculated, And the moment of resistance and driving moment approximately equal；

Step 206, the stand-by motor of both sides works simultaneously, and stand-by motor described in side is as generator operation, together When stand-by motor described in opposite side as electric motor operation, apply the moment of resistance and driving moment respectively to both sides semiaxis 12, realize Poor square power-assisted steering, and provide preferably steering feel for driver；

Step 209, if the poor square servo steering system is not powered off, the stand-by motor is stopped.

As described in Figure 5, in control method of the present invention performance mode step flow chart, comprise the following steps：

Step 304, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and described Speed, calculates the target moment difference of left and right wheelses 13；

Step 305, according to the wheel speed information, the battery voltage information, the battery current information, the battery SOC information, the first stand-by motor rotating speed and the second stand-by motor rotating speed, calculate first stand-by motor 1 or The First Driving Force square of second stand-by motor 2；First Driving Force square institute under current working for the stand-by motor The maximum drive torque that can be provided；

Step 307, work simultaneously if necessary to stand-by motor described in both sides, i.e., described target moment difference is more than described the One driving moment, the driving moment that now stand-by motor of only control drive axle side is provided as electric motor operation can not The moment difference of both sides driving moment 13 is equal to the target moment difference, then calculate the resistance of stand-by motor described in opposite side Torque；

Step 308, the stand-by motor of both sides works simultaneously, and stand-by motor described in side is as generator operation, together When stand-by motor described in opposite side as electric motor operation, apply the moment of resistance and driving moment respectively to both sides semiaxis 12, realize Poor square power-assisted steering, and provide preferably steering feel, the driving that now stand-by motor applies to semiaxis 12 for driver Torque is the First Driving Force square；

Step 309, if do not need stand-by motor described in both sides to work simultaneously, i.e., described target moment difference is less than or equal to The First Driving Force square, the driving force that now stand-by motor of only control drive axle side is provided as electric motor operation Square can make the moment difference of both sides driving moment 13 be equal to the target moment difference, then calculate first stand-by motor The driving moment of 1 or described second stand-by motor 2；

Step 313, if the poor square servo steering system is not powered off, the stand-by motor is stopped.

As described in Figure 6, in control method of the present invention automatic mode step flow chart, comprise the following steps：

Step 404, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and described Speed, calculates the target moment difference of left and right wheelses 13；

Step 405, the moment of resistance or driving moment of first stand-by motor 1 and second stand-by motor 2 are calculated With the braking moment of first brake 9 and the second brake 10, result of calculation should ensure that the security, comfortable of vehicle Property, control stability and dynamic property；

In the description of this specification, reference term " one embodiment ", " some embodiments ", " illustrative examples ", The description of " example ", " specific example " or " some examples " etc. means to combine specific features, the knot that the embodiment or example are described Structure, material or feature are contained at least one embodiment of the present invention or example.In this manual, to above-mentioned term Schematic representation is not necessarily referring to identical embodiment or example.Moreover, specific features, structure, material or the spy of description Point can in an appropriate manner be combined in any one or more embodiments or example.

Although an embodiment of the present invention has been shown and described, it will be understood by those skilled in the art that：Not In the case of departing from the principle and objective of the present invention a variety of change, modification, replacement and modification can be carried out to these embodiments, this The scope of invention is limited by claim and its equivalent.

Claims

1. a kind of poor square servo steering system for automobile drive axle, it is characterised in that the poor square servo steering system is used In the front driving axle or the rear driving axle of engine rear-drive automobile of forerunner's automobile, if the front driving axle for forerunner's automobile, should ensure that vehicle Front-wheel scrub radius be on the occasion of；The system mainly includes executing agency, testing agency, mode of operation selecting unit and Electronic Control Unit (16)；

The executing agency includes stand-by motor, motor gear, electromagnetic clutch, axle shaft gear, battery (11) and brake；

The stand-by motor is by the electromagnetic clutch and the motor gear and the axle shaft gear of a pair of meshing with driving Semiaxis (12) connection of dynamic bridge；The stand-by motor can not only be used as generator but also can be used as motor；The electromagnetic clutch Device is used for when speed exceedes speed setting value, i.e., described poor square servo steering system need not provide power steering for driver When, the power cut off between the stand-by motor and the motor gear is transmitted, it is to avoid the stand-by motor fast idle；The electricity The original state of magnet clutch is engagement state；The motor gear includes the first motor gear (5) and the second motor gear (6)；The structure formed objects of first motor gear (5) and second motor gear (6) are equal；The axle shaft gear bag Include the first axle shaft gear (7) and the second axle shaft gear (8)；First axle shaft gear (7) and second axle shaft gear (8) Structure formed objects are equal；First axle shaft gear (7) is arranged on the left half axle (12) of drive axle；First half axle gear Wheel (7) is engaged with first motor gear (5)；Second axle shaft gear (8) is arranged on the right axle shaft (12) of drive axle； Second axle shaft gear (8) is engaged with second motor gear (6)；The battery (11) is used to store the stand-by motor The electric energy sent, and provide electric energy for the stand-by motor；The brake, which is used to apply side driving moment (13), to be braked Power, so that both sides driving moment (13) produces moment difference；

The testing agency include steering wheel angle sensor, steering-wheel torque sensor, speed probe, voltage sensor and Current sensor；The steering wheel angle sensor is arranged in the steering spindle of steering, for measuring steering wheel angle Size and Orientation, and by steering wheel angle information transmission to the electronic control unit (16)；The steering-wheel torque sensor In the steering spindle of steering, the size and Orientation for measuring torque in steering spindle, i.e. driver act on steering The size and Orientation of torque on disk, and by steering-wheel torque information transmission to the electronic control unit (16)；The rotating speed Sensor includes the first speed probe, the second speed probe, the 3rd speed probe and the 4th speed probe；Described One speed probe, second speed probe, the 3rd speed probe and the 4th speed probe are used respectively In measurement left side driving moment (13), right side driving moment (13), left side non-driven wheel (13) and right side non-driven wheel (13) rotating speed, and by wheel speed information transmission to the electronic control unit (16)；The voltage sensor is used to measure described The terminal voltage of battery (11), and battery voltage information is sent to the electronic control unit (16)；The current sensor is used In the charging and discharging currents for measuring the battery (11), and by battery current information transmission to the electronic control unit (16)；

The mode of operation selecting unit is used to select the different mode of operation of the poor square servo steering system for driver, and Operating mode information is sent to the electronic control unit (16), the electronic control unit (16) is by according to different work Pattern is adjusted to the control strategy of the poor square servo steering system；

The electronic control unit (16) is used to control the switching of the mode of operation and the electromagnetism according to the information received Clutch, the stand-by motor and the brake operation, realize poor square power-assisted steering, and provide preferable steering for driver Feel.

2. a kind of poor square servo steering system for automobile drive axle according to claim 1, it is characterised in that described Stand-by motor includes the first stand-by motor (1) and the second stand-by motor (2)；First stand-by motor (1) and described second auxiliary Help the structure formed objects of motor (2) equal；First stand-by motor (1) is used to provide resistance for the left half axle (12) of drive axle Torque and driving moment；Second stand-by motor (2) is used to provide the moment of resistance and driving force for the right axle shaft (12) of drive axle Square；The stand-by motor should ensure that, driver turn steering wheel, during the poor square servo steering system work, in most operating modes Under, the poor square servo steering system only controls the resistance that the stand-by motor of drive axle side is provided as generator operation Square makes the moment difference that both sides driving moment (13) is produced, it is possible to achieve poor square power-assisted steering, and is provided preferably for driver Turn to feel.

3. a kind of poor square servo steering system for automobile drive axle according to claim 1, it is characterised in that described Electromagnetic clutch includes the first electromagnetic clutch (3) and the second electromagnetic clutch (4)；First electromagnetic clutch (3) and institute The structure formed objects for stating the second electromagnetic clutch (4) are equal；Described first electromagnetic clutch (3) one end and the described first auxiliary The rotating shaft connection of motor (1), the other end is connected with first motor gear (5)；Described second electromagnetic clutch (4) one end with The rotating shaft connection of second stand-by motor (2), the other end is connected with second motor gear (6).

4. a kind of poor square servo steering system for automobile drive axle according to claim 1, it is characterised in that described Brake includes the first brake (9) and second brake (10)；First brake (9) and the second brake (10) Structure formed objects it is equal；First brake (9) is the brake in drive axle left side wheel (13)；Second system Dynamic device (10) is the brake in drive axle right side wheels (13)；The brake is used for, under a small number of operating modes, and the poor square is helped The moment of resistance that power steering only controls the stand-by motor of drive axle side to be provided as generator operation drives both sides The moment difference that wheel (13) is produced, it is impossible to realize poor square power-assisted steering or preferably steering feel can not be provided for driver When, coordinate the stand-by motor work, apply certain brake force to single wheel (13), to increase both sides driving moment (13) Moment difference.

5. a kind of poor square servo steering system for automobile drive axle according to claim 1, it is characterised in that described Mode of operation includes four kinds of patterns：Energy saver mode, balanced mode, performance mode and automatic mode；

When the poor square servo steering system is the energy saver mode, the electronic control unit (16) will be paid the utmost attention to make drive The stand-by motor of dynamic bridge side is as generator operation, while the stand-by motor idle running of opposite side, using described auxiliary Help moment of resistance during electric power generation to make both sides driving moment (13) that there is different driving moment or braking moment, realize that poor square is helped Power is turned to, and provides preferably steering feel for driver, if the stand-by motor of only control drive axle side is used as hair The moment of resistance that motor work is provided makes the moment difference that both sides driving moment (13) is produced, it is impossible to realize poor square power-assisted steering or not It can be provided for driver and preferably turn to feel, then control the brake to coordinate the stand-by motor work, utilize side institute State brake and apply certain brake force, to increase the moment difference of both sides driving moment (13), now conduct to wheel (13) The moment of resistance that the stand-by motor of generator operation applies to semiaxis (12) is first moment of resistance；First moment of resistance is institute State the maximum resistance square that stand-by motor can be provided under current working；

When the poor square servo steering system is the balanced mode, the electronic control unit (16) will control drive axle one The stand-by motor of side is as generator operation, while controlling the stand-by motor of opposite side as electric motor operation, profit The driving moment that stand-by motor described in the moment of resistance and opposite side when being generated electricity with stand-by motor described in side is provided, drives both sides Wheel (13) has different driving moment or braking moment, realizes poor square power-assisted steering, and provide preferable turn for driver To feel, the moment of resistance now applied as the stand-by motor of generator operation to semiaxis (12) and electric motor operation is used as The driving moment approximately equal that applies to semiaxis (12) of the stand-by motor；

When the poor square servo steering system is the performance mode, the electronic control unit (16) will be paid the utmost attention to make drive The stand-by motor of dynamic bridge side is as electric motor operation, while the stand-by motor idle running of opposite side, using described auxiliary The driving moment for helping motor to provide makes both sides driving moment (13) have different driving moments, realizes poor square power-assisted steering, and There is provided for driver and preferably turn to feel, if the stand-by motor of only control drive axle side is carried as electric motor operation The driving moment of confession makes the driving moment difference that both sides driving moment (13) is produced, it is impossible to realizes poor square power-assisted steering or can not be Driver provides and preferably turns to feel, then the stand-by motor for controlling drive axle opposite side coordinates as generator operation As the stand-by motor of electric motor operation, apply certain moment of resistance to opposite side semiaxis (12), to increase both sides driving The moment difference of wheel (13), be to the driving moment that semiaxis (12) applies as the stand-by motor of electric motor operation now First Driving Force square；The First Driving Force square is the maximum driving force that the stand-by motor can be provided under current working Square；

When the poor square servo steering system is the automatic mode, the electronic control unit (16) will consider reception The information arrived, controls the stand-by motor and the brake operation, is ensureing that the poor square servo steering system is energy-efficient On the premise of, there is vehicle and preferably turn to feel, and improve security, comfortableness, control stability and the power of vehicle Property, while making the SOC of the battery (11) maintain in a rational scope；The acquiescence mould of the poor square servo steering system Formula is the automatic mode；

When the poor square servo steering system is the balanced mode or the performance mode, if the battery (11) SOC is less than SOC setting values, and the electronic control unit (16) will intervene the mode of operation, and be switched to institute State automatic mode.

6. a kind of poor square servo steering system for automobile drive axle according to claim 1, it is characterised in that described Electronic control unit (16) includes input module, computing module, mode of operation control module, electromagnetic clutch control module, auxiliary Help motor control module, brake control module and output module；Electronic control unit (16) is according to operating mode information, steering Disk corner information, steering-wheel torque information, wheel speed information, battery voltage information and battery current information control cutting for mode of operation Change with electromagnetic clutch, stand-by motor and brake operation, make left and right sides driving moment (13) have different driving moments Or braking moment, poor square power-assisted steering is realized, and preferably steering feel is provided for driver；

The input module receives operating mode information, steering wheel angle information, steering-wheel torque information, wheel speed information, battery Information of voltage and battery current information, and transmit information to the computing module；

The computing module generates battery SOC information according to battery voltage information and battery current information first；And according to battery SOC information, judges whether the SOC of battery (11) is less than SOC setting values；Secondly current vehicle speed, the are calculated according to wheel speed information One stand-by motor rotating speed and the second stand-by motor rotating speed；And according to speed, judge whether current vehicle speed is equal to zero；If current vehicle speed It is not equal to zero, then judges whether current vehicle speed exceedes speed setting value；Again according to steering wheel angle information, steering-wheel torque letter Breath, wheel speed information and speed, calculate the target moment difference of left and right wheelses (13)；Finally according to operating mode information, turn to Disk corner information, steering-wheel torque information, wheel speed information, battery voltage information, battery current information, battery SOC information, car Speed, the first stand-by motor rotating speed, the second stand-by motor rotating speed and target moment difference, calculate the first stand-by motor (1) and The moment of resistance or driving moment of two stand-by motors (2) and the braking moment of the first brake (9) and second brake (10)；It is described Result of determination and result of calculation are sent to the mode of operation control module, the electromagnetic clutch and control mould by computing module Block, the stand-by motor control module and the brake control module；When for energy saver mode, the computing module will be calculated Go out first moment of resistance of the first stand-by motor (1) or the second stand-by motor (2)；First moment of resistance is stand-by motor in current working Under the maximum resistance square that can be provided；And judge whether to need brake operation, that is, judge whether target moment difference is more than the One moment of resistance；If desired brake operation, i.e. target moment difference are more than first moment of resistance, now only control drive axle side The moment of resistance that stand-by motor is provided as generator operation can not make the moment difference of both sides driving moment (13) be equal to target force Square difference, the computing module will calculate the braking moment of the first brake (9) or second brake (10)；If need not make Dynamic device work, i.e. target moment difference is less than or equal to first moment of resistance, now the only stand-by motor conduct of control drive axle side The moment of resistance that generator operation is provided can make the moment difference of both sides driving moment (13) be equal to target moment difference, the fortune The moment of resistance of the first stand-by motor (1) or the second stand-by motor (2) will be calculated by calculating module；When for balanced mode, drive axle The stand-by motor of both sides works simultaneously, and side stand-by motor is as generator operation, while opposite side stand-by motor is as electronic Machine works, and is used as the moment of resistance that applies to semiaxis (12) of stand-by motor of generator operation and the auxiliary as electric motor operation The driving moment approximately equal that motor applies to semiaxis (12), the computing module will calculate the first stand-by motor (1) and The moment of resistance or driving moment of two stand-by motors (2)；When for performance mode, the computing module will calculate the first auxiliary electricity The First Driving Force square of machine (1) or the second stand-by motor (2)；First Driving Force square can carry for stand-by motor under current working The maximum drive torque of confession；And judge whether to need both sides stand-by motor to work simultaneously, that is, judge whether target moment difference is big In First Driving Force square；If desired both sides stand-by motor works simultaneously, i.e., target moment difference is more than First Driving Force square, now The driving moment that the stand-by motor of only control drive axle side is provided as electric motor operation can not make both sides driving moment (13) Moment difference be equal to target moment difference, the computing module will calculate the moment of resistance of opposite side stand-by motor；If being not required to Want both sides stand-by motor to work simultaneously, i.e., target moment difference is less than or equal to First Driving Force square, now only control drive axle one The driving moment that the stand-by motor of side is provided as electric motor operation can be equal to the moment difference of both sides driving moment (13) Target moment difference, the computing module will calculate the driving moment of the first stand-by motor (1) or the second stand-by motor (2)； When for automatic mode, the computing module will consider the information received, calculate the first stand-by motor (1) and second The moment of resistance or driving moment of stand-by motor (2) and the braking moment of the first brake (9) and second brake (10), are ensureing On the premise of the poor square servo steering system is energy-efficient, there is vehicle and preferably turn to feel, and improve the peace of vehicle Quan Xing, comfortableness, control stability and dynamic property, while making the SOC of battery (11) maintain in a rational scope；

The mode of operation control module generates mode of operation control instruction according to result of determination and result of calculation, and control is referred to Order is sent to the output module, is balanced mode or performance mode in the poor square servo steering system, and battery (11) When SOC is less than SOC setting values, the poor square servo steering system is switched into automatic mode；

The electromagnetic clutch control module generates the control of the first electromagnetic clutch according to the result of determination and result of calculation and referred to Order and the second electromagnetic clutch control instruction, and control instruction is sent to the output module；

The stand-by motor control module according to the result of determination and result of calculation generate the first stand-by motor control instruction and Second stand-by motor control instruction, and control instruction is sent to the output module；

The brake control module generates the first brake control instruction and second according to the result of determination and result of calculation Brake control instruction, and control instruction is sent to the output module；

The output module and the mode of operation selecting unit, first electromagnetic clutch (3), second electromagnetic clutch Device (4), first stand-by motor (1), second stand-by motor (2) and ABS control unit connection, and by mode of operation control System instruction, electromagnetic clutch control instruction and stand-by motor control instruction are sent to target device, and the work of control targe equipment will Brake control instruction is sent to ABS control unit, and the brake operation is controlled by ABS control unit.

7. the control method of a kind of poor square servo steering system for automobile drive axle, it is characterised in that described poor square is helped Power steering includes four kinds of mode of operations：Energy saver mode, balanced mode, performance mode and automatic mode；

The energy saver mode comprises the following steps：

Step 102, if current vehicle speed is not equal to zero, judge whether current vehicle speed exceedes speed setting value；

Step 104, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and the speed, Calculate the target moment difference of left and right wheelses (13)；

Step 105, believed according to the wheel speed information, the battery voltage information, the battery current information, the battery SOC Breath, the first stand-by motor rotating speed and the second stand-by motor rotating speed, calculate first stand-by motor (1) or described First moment of resistance of the second stand-by motor (2)；First moment of resistance is that the stand-by motor can be provided under current working Maximum resistance square；

Step 106, judge whether to need the brake operation, that is, judge whether the target moment difference is more than described first The moment of resistance；

Step 107, if necessary to the brake operation, i.e., described target moment difference is more than first moment of resistance, now The moment of resistance that the stand-by motor of only control drive axle side is provided as generator operation can not make both sides driving moment (13) moment difference is equal to the target moment difference, then calculates first brake (9) or the second brake (10) braking moment；

Step 108, the stand-by motor is as generator operation, while the brake, realizes poor square power-assisted steering, and There is provided for driver and preferably turn to feel, the moment of resistance that now stand-by motor applies to semiaxis (12) is the described first resistance Torque；

Step 109, if not needing the brake operation, i.e., described target moment difference is less than or equal to first resistance Square, the moment of resistance that now stand-by motor of only control drive axle side is provided as generator operation can drive both sides The moment difference of wheel (13) is equal to the target moment difference, then calculates first stand-by motor (1) or described second The moment of resistance of stand-by motor (2)；

Step 110, the stand-by motor realizes poor square power-assisted steering, and provide preferably for driver as generator operation Turn to feel；

Step 111, if current vehicle speed exceedes speed setting value, the electromagnetic clutch separation, it is to avoid the stand-by motor Fast idle；

Step 113, if the poor square servo steering system is not powered off, the stand-by motor is stopped, while described Brake discharges；

The balanced mode comprises the following steps：

Step 202, if current vehicle speed is not equal to zero, judge whether current vehicle speed exceedes speed setting value；

Step 204, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and the speed, Calculate the target moment difference of left and right wheelses (13)；

Step 205, the moment of resistance or driving moment of first stand-by motor (1) and second stand-by motor (2) are calculated, And the moment of resistance and driving moment approximately equal；

Step 206, the stand-by motor of both sides works simultaneously, and stand-by motor described in side is as generator operation, while separately Stand-by motor described in side applies the moment of resistance and driving moment to both sides semiaxis (12) respectively as electric motor operation, and it is poor to realize Square power-assisted steering, and provide preferably steering feel for driver；

Step 207, if current vehicle speed exceedes speed setting value, the electromagnetic clutch separation, it is to avoid the stand-by motor Fast idle；

The performance mode comprises the following steps：

Step 302, if current vehicle speed is not equal to zero, judge whether current vehicle speed exceedes speed setting value；

Step 304, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and the speed, Calculate the target moment difference of left and right wheelses (13)；

Step 305, believed according to the wheel speed information, the battery voltage information, the battery current information, the battery SOC Breath, the first stand-by motor rotating speed and the second stand-by motor rotating speed, calculate first stand-by motor (1) or described The First Driving Force square of second stand-by motor (2)；First Driving Force square institute's energy under current working for the stand-by motor The maximum drive torque of offer；

Step 306, judge whether to need stand-by motor described in both sides to work simultaneously, that is, judge whether the target moment difference is big In the First Driving Force square；

Step 307, worked simultaneously if necessary to stand-by motor described in both sides, i.e., described target moment difference is more than described first and driven Kinetic moment, the driving moment that now stand-by motor of only control drive axle side is provided as electric motor operation can not make two The moment difference of side driving moment (13) is equal to the target moment difference, then calculates the resistance of stand-by motor described in opposite side Square；

Step 308, the stand-by motor of both sides works simultaneously, and stand-by motor described in side is as generator operation, while separately Stand-by motor described in side applies the moment of resistance and driving moment to both sides semiaxis (12) respectively as electric motor operation, and it is poor to realize Square power-assisted steering, and provide preferably steering feel, the driving that now stand-by motor applies to semiaxis (12) for driver Torque is the First Driving Force square；

Step 309, if do not need stand-by motor described in both sides to work simultaneously, i.e., described target moment difference is less than or equal to described First Driving Force square, the driving moment that now stand-by motor of only control drive axle side is provided as electric motor operation can So that the moment difference of both sides driving moment (13) is equal to the target moment difference, then first stand-by motor is calculated (1) or second stand-by motor (2) driving moment；

Step 310, the stand-by motor realizes poor square power-assisted steering, and provide preferably for driver as electric motor operation Turn to feel；

Step 311, if current vehicle speed exceedes speed setting value, the electromagnetic clutch separation, it is to avoid the stand-by motor Fast idle；

The automatic mode comprises the following steps：

Step 402, if current vehicle speed is not equal to zero, judge whether current vehicle speed exceedes speed setting value；

Step 404, according to the steering wheel angle information, the steering-wheel torque information, the wheel speed information and the speed, Calculate the target moment difference of left and right wheelses (13)；

Step 405, the moment of resistance or driving moment of first stand-by motor (1) and second stand-by motor (2) are calculated With first brake (9) and the braking moment of the second brake (10), result of calculation should ensure that vehicle security, Comfortableness, control stability and dynamic property；

Step 406, the stand-by motor work, the brake, are efficiently saved in the guarantee poor square servo steering system On the premise of energy, poor square power-assisted steering is realized, and preferably steering feel is provided for driver；

Step 407, if current vehicle speed exceedes speed setting value, the electromagnetic clutch separation, it is to avoid the stand-by motor Fast idle；

Step 409, if the poor square servo steering system is not powered off, the stand-by motor is stopped, while described Brake discharges.