CN103754207A - Method for controlling double-motor electric-hydraulic composite brake system on basis of force control - Google Patents

Abstract

The invention discloses a method for controlling a double-motor electric-hydraulic composite brake system on the basis of force control. The method includes controlling a brake motor to control target torque of the brake motor so as to brake a pedal force motor under the matching effect of the pedal force motor and regenerative brake force to generate corresponding target brake force; controlling a pedal force simulating motor to control brake pedal feel provided for a driver, and braking the pedal force motor under the matching effect of the pedal force motor and regenerative brake force to generate corresponding target brake force. The brake motor and the pedal force simulating motor are controlled in a force control mode. The method for controlling the double-motor electric-hydraulic composite brake system has the advantages the double-motor electric-hydraulic composite brake system can be controlled precisely, the robustness is excellent, and the excellent brake feel can be provided for the driver on the premise that brake intension of the driver can be implemented.

Description

A kind of double-motor Electro-hydraulic brake system control method of controlling based on power

Technical field

The invention belongs to automobile technical field, relate to brake system control technology, the double-motor Electro-hydraulic brake system control method of especially controlling based on power.

Background technology

Brake system is the vital system of relevant vehicle safety performance, and the height of its performance will directly affect the driving safety performance of car load.Traditional brake system, conventionally by brake pedal, vacuum booster, master brake cylinder, ESC/ABS, brake wheel cylinder and corresponding pipeline thereof form.Whole system is comparatively complicated, and at volume, in quality and integrated level, is in a disadvantageous position.And, along with the continuous lifting of engine efficiency, its degree of vacuum that can provide to vacuum booster just more and more limited.This problem of bringing in order to make up high efficience motor, a lot of vehicles take the scheme of addition of vacuum pump to increase degree of vacuum.Yet this this scheme is an interim solution.The vacuum pump increasing has not only taken limited vehicle fore cabin space, has also increased quality and the failure risk of brake system simultaneously.This runs in the opposite direction for vehicle and lightweight and safety.Therefore, responding fast, powerful EHB just more and more receives publicity.

Mechanical electronic mode EHB has braking motor conventionally, master brake cylinder, and pressure of wheel braking cylinder control cock, pedal simulator, inefficacy standby system and associated pipe thereof form.This system is being different from now the progressively EHB of mass production, abandoned high pressure accumulator with and relevant control valve system, directly by braking motor, drive master cylinder completion system to build pressure.Compare to EHB, mechanical electronic mode EHB has been avoided adopting and has been had the high pressure accumulator of risk of leakage and relevant control cock system thereof, from cost and reliability, more goes a step further.In addition, a kind of as brake-by-wire (brake by wire), mechanical electronic mode EHB is simple in structure, can realize the brake-pressure of each wheel cylinder accurately controls, except realizing the braking anti-lock of traditional braking system, control, drive anti-skidding control, electronic braking force distributes to be controlled, outside the functions such as electronic stability control, can also be only by having write of software, emergency braking is auxiliary, braking pitch control subsystem, a series of functions such as brake disc moisture film is removed, and uphill starting is auxiliary.What is more important, due to system be decoupled system, this system can with the perfect adaptation of regenerative brake power, under the help of pedal simulator, realize that not change original brake feel be that the braking energy of prerequisite reclaims and maximizes.Therefore the employing of mechanical electronic mode EHB and the popularization safety of lifting vehicle in all directions, economy and lightweight, be to be all with a wide range of applications in conventional truck or on new energy vehicle.

Some external automobile relevant enterprises have started to drop into energetically the exploitation of mechanical electronic mode EHB.Wherein the iBooster of BOSCH company adopts turbine and worm decelerator to coordinate the form of braking motor.The e-Actuator system of HIT is to have realized mechanical electronic mode EHB by Outsourcing-type motor and ball-screw.In addition, CPG Gmbh & Co., LSP company, U.S. TRW Ltd. (US) One Space Park, Redondo Beach CA 90278 U.S.A. is main directions using mechanical electronic mode EHB as brake system future development all also, and plan to realize volume production in 10 years.

And a kind of as in mechanical electronic mode EHB of double-motor Electro-hydraulic brake system, due to its compact conformation, hydraulic pressure components and parts are less, make full use of numerous advantages such as driver pedal power, just gradually paid close attention to widely.

Although its structure has obvious advantage compared to other mechanical electronic mode EHBs.But because it has adopted Double Motor Control pattern, it controls the corresponding increase of difficulty.In addition,, in order to make full use of the brake pedal force of chaufeur, system has been taked non-full decoupled system decoupling.Therefore, the control target of dual motors system compares to mechanical electronic mode EHB and controls from single master cylinder thrust, expands to two controls of controlling target of master cylinder thrust and brake pedal feedback force.Therefore, this control method to double-motor Electro-hydraulic brake system has proposed higher requirement.

In order to solve this control problem, be necessary to develop a kind of double-motor Electro-hydraulic brake system control method of controlling based on power, this control method adopts braking motor control logic and treadle effort simulated machine control logic to realize the independent of master cylinder thrust and brake pedal feedback force and controls, thereby meeting under the prerequisite of car load demand braking force, guaranteeing good brake pedal feel.

Summary of the invention

The object of this invention is to provide a kind of double-motor Electro-hydraulic brake system control method of controlling based on power, to overcome above-mentioned said double-motor Electro-hydraulic brake system, control the higher problem of difficulty.

For achieving the above object, solution of the present invention is:

A double-motor Electro-hydraulic brake system control method of controlling based on power, comprising:

Control braking motor: control the target moment of braking motor, thereby coordinate brake pedal force motor and regenerative brake power to produce corresponding target braking force;

Control pedal power simulated machine: control the brake pedal feel that chaufeur is provided, coordinate brake pedal force motor and regenerative brake power to produce corresponding target braking force simultaneously.

Further, for the control of braking motor, what take is power mode.

For the control of treadle effort simulated machine, what take is power mode.

By realizing the independent of master cylinder thrust and brake pedal feedback force, control, thereby meeting under the prerequisite of car load demand braking force, guarantee good brake pedal feel.

By coordinating with the communication of whole-control system VMS, realize the reasonable coupling of regenerative brake power and friction brake force, thereby realize the braking energy recovery maximization of system.

Described machine double-motor Electro-hydraulic brake system control method obtains regenerative brake power by whole-control system VMS, thereby carries out further logic judgement and arbitration.

When chaufeur, trample brake pedal and produce after corresponding brake pedal displacement, system tries hard to obtain the car load total braking force demand of target by inquiry brake pedal displacement/brake pedal; Meanwhile, whole-control system VMS considers the operational factor of vehicle, thereby determines regenerative brake power; After VMS obtains regenerative brake power by vehicle-state, VMS sends to system by the regenerative brake power of vehicle;

After system acquisition target car load total braking force demand and regenerative brake power, it is asked to poor, thereby obtain target friction brake force, system obtains the target propulsive force of braking motor and treadle effort simulated machine afterwards, thereby realizes braking procedure by electric machine controller.

System obtains target master brake cylinder thrust by following formula:

$F_{\mathrm{mc}}=\frac{F_b\&times;\mathrm{\&beta;}\&times;r_{\mathrm{wheel}}\&times;{{\mathrm{<figure-callout\; id="2"\; label="r\; mc"\; filenames="2014100083911100003DEST\_PATH\_IMAGE001.png"\; state="\{\{state\}\}">r</figure-callout>}}_{\mathrm{mc}}}^2}{4\&times;r_{\mathrm{caliper}}\&times;\mathrm{\&mu;}\&times;{r_w}^2}---\left(1\right)$

F in formula _mcfor target master brake cylinder thrust; F _bfor target friction brake force; β is brake-power balance coefficient; r _wheelfor vehicle wheel roll radius; r _mcfor master cylinder radius; r _caliperfor friction lining effective brake radius; μ is the friction coefficient between front brake plate and brake disc; r _wfor wheel cylinder radius.

After having obtained target master brake cylinder thrust, system by obtaining brake pedal force expected value from desirable brake pedal displacement/pedal is tried hard to; Afterwards, system is asked the poor braking motor target propulsive force that obtains by target master brake cylinder thrust and brake pedal force expected value, as shown in the formula:

F _bm=F _mc-F _pedal×i (2)

F in formula _mcfor master brake cylinder target propulsive force; F _bmfor target braking motor thrust; F _pedalfor brake pedal force expected value; I is brake pedal lever ratio;

F _PFE=F _pedal×i (3)

Meanwhile, system is by treadle effort simulated machine target propulsive force F _pFEsend to treadle effort simulated machine, make it result from the consistent brake pedal feedback force of required brake pedal force;

So far, system acquisition the target propulsive force of two motors, the dependent instruction of target propulsive force is sent to electric machine controller, motor controller controls corresponding motor produces target propulsive force, complete braking and treadle effort simulation, thereby realize when controlling brake fluid pressure and complete initiatively treadle effort simulation, in addition, also take into account and utilized manpower.

According to an aspect of the present invention, a kind of double-motor Electro-hydraulic brake system control method of controlling based on power is provided, comprise: braking motor control logic, for controlling the target moment of braking motor, thereby coordinate brake pedal force motor and regenerative brake power to produce corresponding target braking force; Treadle effort simulated machine control logic for controlling the brake pedal feel that chaufeur is provided, coordinates brake pedal force motor and regenerative brake power to produce corresponding target braking force simultaneously.

Preferably, described machine double-motor Electro-hydraulic brake system control method obtains regenerative brake power by whole-control system (VMS), thereby carries out further logic judgement and arbitration.

The present invention adopts braking motor control logic and treadle effort simulated machine control logic to realize the independent of master cylinder thrust and brake pedal feedback force and controls, thereby is meeting under the prerequisite of car load demand braking force, guarantees good brake pedal feel.

Accompanying drawing explanation

Fig. 1 is according to the sketch of the double-motor Electro-hydraulic brake system control method of controlling based on power of one exemplary embodiment of the present invention;

Fig. 2 is the sketch of the double-motor Electro-hydraulic brake system control method system based on power control according to the utilization of one exemplary embodiment of the present invention;

Fig. 3 is that the maximum regeneration braking force arriving involved in the present invention is with the variation diagram of the speed of a motor vehicle.

The specific embodiment

Below in conjunction with accompanying drawing illustrated embodiment, the present invention is further illustrated.

When chaufeur, trample brake pedal and produce after corresponding brake pedal displacement, system tries hard to obtain the car load total braking force demand of target by inquiry brake pedal displacement/brake pedal.Meanwhile, VMS obtains maximum regeneration braking force by the driving states of vehicle.Maximum regeneration braking force with the variation of the speed of a motor vehicle as shown in Figure 3.When vehicle travels with the low-down speed of a motor vehicle, because the moment of electrical motor when the low speed has unsettled feature, there is a lot of fluctuations.Therefore, when vehicle is in utmost point lower-speed state lower time, regenerative brake is not worked conventionally, and the braking of vehicle is all completed by traditional hydraulic brake system.And when vehicle is during in lower-speed state, due to lower at the work efficiency of this work area motor, conventionally only has 50% left and right.The heating of the regeneration brake system of therefore, working in this work area is very serious.Therefore, the regenerative braking moment in this regional work is limited.When vehicle is during in middling speed, because the current limit of electric machine controller is limited in below a constant maximum torque line regenerative braking moment.And when vehicle is during in high speed, the maximum braking force of regenerative brake is limited in again below controller maximum power line.Finally, regenerative braking moment is limited in certain speed of a motor vehicle by the highest motor speed.In addition regenerative brake power value and other vehicle parameters, as on-vehicle battery SOC value etc. also has impact to the maximum regeneration braking force of vehicle, system will consider the operational factor of vehicle, thereby determines regenerative brake power.After VMS obtains regenerative brake power by vehicle-state, VMS sends to system by the regenerative brake power of vehicle.

After system acquisition target car load total braking force demand and regenerative brake power, it is asked to poor, thereby obtain target friction brake force.System obtains target master brake cylinder thrust by following formula afterwards:

$F_{\mathrm{mc}}=\frac{F_b\&times;\mathrm{\&beta;}\&times;r_{\mathrm{wheel}}\&times;{{\mathrm{<figure-callout\; id="2"\; label="r\; wc"\; filenames="2014100083911100003DEST\_PATH\_IMAGE001.png"\; state="\{\{state\}\}">r</figure-callout>}}_{\mathrm{wc}}}^2}{4\&times;r_{\mathrm{caliper}}\&times;\mathrm{\&mu;}\&times;{r_w}^2}---\left(1\right)$

F in formula _mcfor target master brake cylinder thrust; F _bfor target friction brake force; β is brake-power balance coefficient; r _wheelfor vehicle wheel roll radius; r _mcfor master cylinder radius; r _caliperfor friction lining effective brake radius; μ is the friction coefficient between front brake plate and brake disc; r _wfor wheel cylinder radius.

After having obtained target master brake cylinder thrust, system by having obtained brake pedal force expected value from desirable brake pedal displacement/pedal is tried hard to.Afterwards, system is asked the poor braking motor target propulsive force that obtains by target master brake cylinder thrust and brake pedal force expected value, as shown in the formula:

F _bm=F _mc-F _pedal×i (2)

F in formula _mcfor master brake cylinder target propulsive force; F _bmfor target braking motor thrust; F _pedalfor brake pedal force expected value; I is brake pedal lever ratio.

F _PFE=F _pedal×i (3)

Meanwhile, system is by treadle effort simulated machine target propulsive force F _pFEsend to treadle effort simulated machine, make it result from the consistent brake pedal feedback force of required brake pedal force.

As, when obtaining target friction brake force F _b=5000N, brake-power balance coefficient β=0.7, vehicle wheel roll radius r _wheel=0.25m, master cylinder radius r _mc=11.1mm, friction lining effective brake radius r _caliper=0.1m, coefficientoffrictionμ=0.4 between front brake plate and brake disc, is wheel cylinder radius r _w=26mm.Through type (1) calculates F _mc=996N.Meanwhile, pedal displacement sensor obtains chaufeur brake pedal displacement S _pedal=30mm, tries hard to obtain brake pedal expected value F by desirable brake pedal displacement/pedal _pedal=50N.Be equipped with moving foot pedal lever than i=4, through type (2) obtains F _bm=796N, through type (3) obtains F _pFE=200N.

So far, system acquisition the target propulsive force of two motors, the dependent instruction of target propulsive force is sent to electric machine controller, motor controller controls corresponding motor produces target propulsive force, completes braking and treadle effort and simulates.Thereby realize when controlling brake fluid pressure and complete initiatively treadle effort simulation, in addition, also take into account and utilized manpower.

Fig. 1 shows according to the sketch of the double-motor Electro-hydraulic brake system control method of controlling based on power of one exemplary embodiment of the present invention.

Fig. 2 shows the sketch of the double-motor Electro-hydraulic brake system control method system of controlling based on power according to the utilization of one exemplary embodiment of the present invention.

As shown in Figure 1, the double-motor Electro-hydraulic brake system control method that should control based on power mainly comprises: braking motor control logic, for controlling the target moment of braking motor, thereby coordinate brake pedal force motor and regenerative brake power to produce corresponding target braking force; Treadle effort simulated machine control logic for controlling the brake pedal feel that chaufeur is provided, coordinates brake pedal force motor and regenerative brake power to produce corresponding target braking force simultaneously.

During normal work, chaufeur operates brake pedal according to vehicle condition and road conditions, system receives the displacement signal of brake pedal by brake pedal displacement pickup, from VMS, obtain regenerative brake power value and other vehicle parameters simultaneously, as after on-vehicle battery SOC value etc., by the above-mentioned double-motor Electro-hydraulic brake system control method of controlling based on power, obtain relevant braking motor target propulsive force and treadle effort simulated machine target propulsive force.In the process that obtains braking motor target propulsive force, need to consider the motor regenerative braking moment restriction shown in Fig. 3.Maximum regeneration braking force with the variation of the speed of a motor vehicle as shown in Figure 3.When vehicle travels with the low-down speed of a motor vehicle, because the moment of electrical motor when the low speed has unsettled feature, there is a lot of fluctuations.Therefore, when vehicle is in utmost point lower-speed state lower time, regenerative brake is not worked conventionally, and the braking of vehicle is all completed by traditional hydraulic brake system.And when vehicle is during in lower-speed state, due to lower at the work efficiency of this work area motor, conventionally only has 50% left and right.The heating of the regeneration brake system of therefore, working in this work area is very serious.Therefore, the regenerative braking moment in this regional work is limited.When vehicle is during in middling speed, because the current limit of electric machine controller is limited in below a constant maximum torque line regenerative braking moment.And when vehicle is during in high speed, the maximum braking force of regenerative brake is limited in again below controller maximum power line.Finally, regenerative braking moment is limited in certain speed of a motor vehicle by the highest motor speed.Obtain after braking motor target propulsive force, as above routine described F _bm=796N, as shown in Figure 2, brake system controller will drive order to send to electric machine controller 25 accordingly, and then drive braking motor 2.Braking motor 2 obtains the speed reduction gearing 3 that hydraulic braking order rear drive motor drives, and drives afterwards push rod 20, thereby promotes master brake cylinder 11.In the cylinder of master brake cylinder, conventionally there are two pistons: the first brake piston and the second brake piston.The first brake piston and the second brake piston are divided into two hydraulic cavities of hydraulic isolation each other by hydraulic actuating cylinder: the first hydraulic cavities and the second hydraulic cavities.The first hydraulic cavities and the second hydraulic cavities are connected to ABS/ESC by two hydraulic tubings respectively.Therefore, after promotion master brake cylinder, brake wheel cylinder produces corresponding hydraulic braking force.

Obtain after treadle effort simulated machine target propulsive force, as above routine described F _pFE=200N, brake system controller will drive order to send to electric machine controller 25 accordingly, and then drive treadle effort simulated machine 22.Treadle effort simulated machine 22 obtains the speed reduction gearing that hydraulic braking order rear drive motor drives, and promotes afterwards brake pedal 21 and produces corresponding brake pedal feel.

The above-mentioned description to embodiment is can understand and apply the invention for ease of those skilled in the art.Person skilled in the art obviously can easily make various modifications to these embodiment, and General Principle described herein is applied in other embodiment and needn't passes through performing creative labour.Therefore, the invention is not restricted to the embodiments described, and those skilled in the art are according to announcement of the present invention, and not departing from the improvement that category of the present invention makes and revise all should be within protection scope of the present invention.

Claims (9)

1. a double-motor Electro-hydraulic brake system control method of controlling based on power, is characterized in that: comprising:

Control braking motor: control the target moment of braking motor, thereby coordinate brake pedal force motor and regenerative brake power to produce corresponding target braking force;

Control pedal power simulated machine: control the brake pedal feel that chaufeur is provided, coordinate brake pedal force motor and regenerative brake power to produce corresponding target braking force simultaneously.

2. the method for claim 1, is characterized in that: for the control of braking motor, what take is power mode.

3. the method for claim 1, is characterized in that: for the control of treadle effort simulated machine, what take is power mode.

4. method as claimed in claim 2 or claim 3, is characterized in that: by realizing the independent of master cylinder thrust and brake pedal feedback force, control, thereby meeting under the prerequisite of car load demand braking force, guarantee good brake pedal feel.

5. method as claimed in claim 4, is characterized in that: by coordinating with the communication of whole-control system VMS, realize the reasonable coupling of regenerative brake power and friction brake force, thereby realize the braking energy recovery maximization of system.

6. method as claimed in claim 5, is characterized in that: described machine double-motor Electro-hydraulic brake system control method obtains regenerative brake power by whole-control system VMS, thereby carries out further logic judgement and arbitration.

7. method as claimed in claim 6, is characterized in that: when chaufeur, trample brake pedal and produce after corresponding brake pedal displacement, system tries hard to obtain the car load total braking force demand of target by inquiry brake pedal displacement/brake pedal; Meanwhile, whole-control system VMS considers the operational factor of vehicle, thereby determines regenerative brake power; After VMS obtains regenerative brake power by vehicle-state, VMS sends to system by the regenerative brake power of vehicle;

After system acquisition target car load total braking force demand and regenerative brake power, it is asked to poor, thereby obtain target friction brake force, system obtains the target propulsive force of braking motor and treadle effort simulated machine afterwards, thereby realizes braking procedure by electric machine controller.

8. method as claimed in claim 7, is characterized in that: system obtains target master brake cylinder thrust by following formula:

$F_{\mathrm{mc}}=\frac{F_b\&times;\mathrm{\&beta;}\&times;r_{\mathrm{wheel}}\&times;{r_{\mathrm{mc}}}^2}{4\&times;r_{\mathrm{caliper}}\&times;\mathrm{\&mu;}\&times;{r_w}^2}---\left(1\right)$

F in formula _mcfor target master brake cylinder thrust; F _bfor target friction brake force; β is brake-power balance coefficient; r _wheelfor vehicle wheel roll radius; r _mcfor master cylinder radius; r _caliperfor friction lining effective brake radius; μ is the friction coefficient between front brake plate and brake disc; r _wfor wheel cylinder radius.

9. method as claimed in claim 8, is characterized in that: after having obtained target master brake cylinder thrust, system by obtaining brake pedal force expected value from desirable brake pedal displacement/pedal is tried hard to; Afterwards, system is asked the poor braking motor target propulsive force that obtains by target master brake cylinder thrust and brake pedal force expected value, as shown in the formula:

F _bm=F _mc-F _pedal×i (2)

F in formula _mcfor master brake cylinder target propulsive force; F _bmfor target braking motor thrust; F _pedalfor brake pedal force expected value; I is brake pedal lever ratio;

F _PFE=F _pedal×i (3)

Meanwhile, system is by treadle effort simulated machine target propulsive force F _pFEsend to treadle effort simulated machine, make it result from the consistent brake pedal feedback force of required brake pedal force;

So far, system acquisition the target propulsive force of two motors, the dependent instruction of target propulsive force is sent to electric machine controller, motor controller controls corresponding motor produces target propulsive force, complete braking and treadle effort simulation, thereby when realizing control brake fluid pressure, complete initiatively treadle effort simulation.

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