CN103707870A - Method for obtaining and protecting piston position of aircraft electric brake actuator - Google Patents

Abstract

The invention relates to a method for obtaining and protecting the piston position of an aircraft electric brake actuator. According to the method, position information of a piston can be obtained in real time in the working process of an aircraft brake system, and therefore the problems that the piston easily exerts force in the reverse direction to be stuck when the actuator is in the zero alignment process and the deep skid resistance process can be effectively solved, and the strong support is provided for stable and reliable running of the aircraft electric brake system.

Description

Obtaining and guard method of a kind of piston position of Electric Brake System of Aircraft actuator

Technical field

The present invention relates to Electric Brake System of Aircraft system, be specially a kind of the obtaining and guard method of piston position of Electric Brake System of Aircraft actuator.

Background technology

Brake system is an important subsystem of aircraft, and its function is the take-off and landing safety that guarantees aircraft, and the coasting distance while shortening aircraft landing as much as possible on this basis.

Full electric brake system is the airplane brake system of new generation of competitively developing both at home and abroad, it replaces the hydraulic actuation mechanism of existing brake system by dynamo-electric actuation mechanism, control signal and power signal all pass through electrical communications, no longer need the hydraulic packages such as any conduit under fluid pressure, pump and valve.

In Electric Brake System of Aircraft system, electromechanical actuator exert oneself and the power of unloading compresses and leaves brake disc by direct motor drive piston and realizes, electrical motor adopts the brushless direct current motor with three road hall position sensors conventionally.

At present, in the relevant disclosed patent in Electric Brake System of Aircraft actuator control aspect and the paper delivered, conventionally only utilize the value of feedback of pressure sensor to carry out the control of brake weight, and this Important Parameters of the actual position of piston is not had to concern too much.Although this processing mode can realize the function of basic electric brake, be but difficult to guarantee precision and the reliability of whole brake process.

Reason is mainly manifested in following two aspects:

(1) before brake, processings of will once returning to zero of the piston of actuator, make it and brake disc between keep certain gap, about about 3mm.Due to when piston leaves brake disc, the value of feedback of pressure sensor has been zero, therefore cannot continue according to the feedback information of power, piston to be controlled effectively.This will cause piston cannot reliably be positioned to zero-bit, and piston may cannot stretch out because reverse stroke is excessive and stuck in actuator, thereby cause, brakes unsuccessfully.

(2) in brake process, when wheel enters deeply when anti-skidding, require actuator to unload fast power, making brake weight is zero, also requires piston and brake disc to be close to simultaneously, can respond fast when guaranteeing again to exert oneself.Because controller inevitably exists error to the collection of pressure sensor feedback signal, making brake weight is that zero given value is difficult to determine.If given value is bigger than normal, cannot guarantee that it is zero that actuator is exerted oneself; If less than normal, piston equally can be stuck in actuator because retreat always.

If can obtain the position of piston, not only can coordinate the feedback information of pressure sensor to complete reliably zeroing and dark anti-skidding requirement, can also process in time the failure condition on the anti-top of piston, realized the defencive function for piston.This reliable and stable operation for airplane brake system has vital effect.

Summary of the invention

The technical matters solving

For fear of the deficiencies in the prior art part, the present invention proposes a kind of the obtaining and guard method of piston position of Electric Brake System of Aircraft actuator.

Technical scheme

Obtaining and a guard method of the piston position of Electric Brake System of Aircraft actuator, is characterized in that step is as follows:

Step 1: control in the initialization of software in actuator, next hall position state table HallForward[8 while storing respectively piston forward and inverted running] and HallBackward[8], Hall counting machine HallCnt is initialized as 0, the piston position boundary limitation relational expression that storage is exerted oneself corresponding with actuator:

HallCnt _min＝f _min(F-F ₀)+N ₀，HallCnt _max＝f _max(F-F ₀)+N ₀

Function f wherein _minand f _maxaccording to actuator, exert oneself and obtain by data fitting with the test data of piston position corresponding relation, F is the Real-time Feedback value of power sensor, F ₀for the preset value for piston zeroing location, span 500N～1000N, N ₀the distance of piston and zero-bit when expression pressure reaches preset value, value is determined by experimental debugging;

Step 2: after power circuit being detected and powering on, control plunger presses to brake disc until the signal output of power sensor reaches preset value F ₀, now give Hall counting machine HallCnt assignment N ₀;

Step 3: control plunger inverted running, often through a Hall state Hall counting machine HallCnt, subtract 1, when Hall counting machine HallCnt is zero, stops motor and to the processing of returning to zero of the piston of actuator, make to keep between piston and brake disc the gap of 3mm;

Step 4: when entering braking state, store the state value CurState of current hall position sensor, according to the service direction of piston, next hall position state table HallForward[8 when searching piston forward and inverted running] and HallBackward[8] known next state value is NextState

Step 5: when new state value NewState arrives, judge whether NewState equals NextState: if equal, HallCnt adds 1 or subtract 1 according to piston service direction, and the value of NewState is assigned to CurState; If be not equal to, do not count, and the value of CurState remains unchanged;

Step 6: calculate in real time the interval [HallCnt of Hall count restrictions according to the brake weight of feedback _min, HallCnt _max];

Step 7: judge whether current Hall count value meets boundary limitation condition: if meet, this location information is effective; Otherwise, if HallCnt<HallCnt _min, make HallCnt=HallCnt _min; If HallCnt>HallCnt _max, make HallCnt=HallCnt _max;

Step 8: according to the power sensor Real-time Feedback value F collecting, calculate the slope F' of current brake weight:

$F^{\&prime;}=\frac{F\left(k\right)-F(k-M)}{M\&CenterDot;T}$

The power sensor sample value that wherein F (k) is current control cycle, F (k-M) is the power sensor sample value of a front M control cycle, T is the sampling time;

Step 9: if the slope of current brake weight feedback be on the occasion of, and piston direction is for negative, judgement piston is in anti-top state, stops immediately motor protection; Otherwise piston position state is normal, is back to step 4, proceeds position calculation.

Beneficial effect

Obtaining and guard method of the piston position of a kind of Electric Brake System of Aircraft actuator that the present invention proposes; can be in airplane brake system working process the location information of Real-time Obtaining piston; thereby can actv. avoid actuator zeroing and dark when anti-skidding piston easily oppositely exert oneself and stuck problem, for the reliable and stable operation of Electric Brake System of Aircraft system provides strong support.

Accompanying drawing explanation

Obtaining and guard method diagram of circuit of Fig. 1 piston position

The structural representation of electromechanical actuator in Fig. 2 Electric Brake System of Aircraft system

Fig. 3 brushless DC motor driving controller constructional drawing

The position view of piston in Fig. 4 brake process

Force feedback signal mode chart in Fig. 5 piston zeroing process

The mode chart of the given and force-feedback response of power in the dark anti-skidding process of Fig. 6

The specific embodiment

Now in conjunction with the embodiments, the invention will be further described for accompanying drawing:

In Electric Brake System of Aircraft system, the structure of electromechanical actuator as shown in Figure 2, actuator mainly consists of brake Moving plate, brake quiet dish, piston, ball-screw, reducing gear and brushless direct current motor, the number of pole-pairs of motor is 3, and its hall position sensor is positioned at the rearward end of motor.

As shown in Figure 3, main power section adopts three-phase full-bridge inverter to the structure of brushless DC motor driving controller, and DC bus-bar voltage is 160V, and power switch pipe adopts N channel power MOS FET, and switching frequency is made as 20kHz, drives chip to adopt IR2130.Control unit is powered by 28V, adopts TMS320F2812 as main control chip, utilizes A and D converter on its sheet to gather the feedback signal of pressure sensor, utilizes its trapping module to catch hall position sensor output San road signal.

Step 1: macro definition F ₀be 800, represent when power sensor feedback value reaches 800N, to think that piston reliably contacts with brake disc; Definition N ₀be 70, representing needs 70 hall position states of inverted running to reach zero-bit after piston contacts with brake disc, between piston and brake disc, keeps the gap of 3mm left and right.All debugging is definite by experiment for two parameters.With two one dimension variable HallForward[8]=0,5,3,1,6,4,2,0} and HallBackward[8]=0,3,6,2,5, Isosorbide-5-Nitrae, the value of next hall position state when 0} storage piston forward and inverted running.Counting machine HallCnt is initialized as 0.The piston position boundary limitation relational expression that storage is exerted oneself corresponding with actuator: HallCnt _min=f _min(F-F ₀)+N ₀, HallCnt _max=f _max(F-F ₀)+N ₀.The trapping module of initialization control chip, catches hall sensor signal;

Step 2: detect after 160V powered on, control plunger presses to brake disc until the signal output of power sensor reaches predetermined value F ₀, i.e. 800N, this hour counter HallCnt assignment is N ₀, 70;

Step 3: control plunger inverted running, often through a Hall state counter HallCnt, subtract 1, until stop motor while being zero, stop motor and to the processing of returning to zero of the piston of actuator, make to keep between piston and brake disc the gap of 3mm;

Step 4: when entering braking state, first store the state value CurState of current hall position sensor, according to the service direction of piston, by the HallForward[8 that tables look-up] and HallBackward[8] known next state value is NextState;

Step 5: when new state value NewState arrives, judge whether NewState equates with NextState.If equate, HallCnt adds 1 or subtract 1 according to piston direction, and the value of NewState is assigned to CurState; If unequal, do not count, and the value of CurState remains unchanged;

Step 6: calculate corresponding piston position boundary limitation interval [HallCntmin, HallCntmax] according to force feedback value;

Step 7: the piston position for obtaining, judges whether to meet boundary limitation condition.If meet, this location information is effective; Otherwise, if HallCnt<HallCntmin makes HallCnt=HallCntmin; If HallCnt>HallCntmax, makes HallCnt=HallCntmax;

Step 8: the slope F' that calculates force feedback signal according to the sampled value of power sensor:

$F^{\&prime;}=\frac{F\left(k\right)-F(k-M)}{M\&CenterDot;T}$

The power sensor sample value that wherein F (k) is current control cycle, F (k-M) is the power sensor sample value of a front M control cycle, and the sampling time, T was set to 2.5ms, and the sampling interval M of a slope of every calculating is 10;

Step 9: if slope be on the occasion of, and piston direction is for negative, judges that piston is in anti-top state, stops immediately motor protection.Otherwise, show that piston position state is normal, turn back to step 4, proceed position calculation.

Tool of the present invention has the following advantages:

(1) only utilize hall position sensor and the pressure sensor of system itself, without other displacement pickups, just can obtain more exactly the position of piston, as shown in Figure 4;

(2) to out of control by piston and anti-top that cause situation can be protected in time;

(3) realize accurately, reliably the zeroing of piston, as shown in Figure 5;

(4) the piston position information obtaining coordinates with power sensor can meet dark property indices when anti-skidding well, as shown in Figure 6.

Claims (1)

1. obtaining and a guard method of the piston position of Electric Brake System of Aircraft actuator, is characterized in that step is as follows:

Step 1: control in the initialization of software in actuator, next hall position state table HallForward[8 while storing respectively piston forward and inverted running] and HallBackward[8], Hall counting machine HallCnt is initialized as 0, the piston position boundary limitation relational expression that storage is exerted oneself corresponding with actuator:

HallCnt _min＝f _min(F-F ₀)+N ₀，HallCnt _max＝f _max(F-F ₀)+N ₀

Function f wherein _minand f _maxaccording to actuator, exert oneself and obtain by data fitting with the test data of piston position corresponding relation, F is the Real-time Feedback value of power sensor, F ₀for the preset value for piston zeroing location, span 500N～1000N, N ₀the distance of piston and zero-bit when expression pressure reaches preset value, value is determined by experimental debugging;

Step 2: after power circuit being detected and powering on, control plunger presses to brake disc until the signal output of power sensor reaches preset value F ₀, now give Hall counting machine HallCnt assignment N ₀;

Step 3: control plunger inverted running, often through a Hall state Hall counting machine HallCnt, subtract 1, when Hall counting machine HallCnt is zero, stops motor and to the processing of returning to zero of the piston of actuator, make to keep between piston and brake disc the gap of 3mm;

Step 4: when entering braking state, store the state value CurState of current hall position sensor, according to the service direction of piston, next hall position state table HallForward[8 when searching piston forward and inverted running] and HallBackward[8] known next state value is NextState

Step 5: when new state value NewState arrives, judge whether NewState equals NextState: if equal, HallCnt adds 1 or subtract 1 according to piston service direction, and the value of NewState is assigned to CurState; If be not equal to, do not count, and the value of CurState remains unchanged;

Step 6: calculate in real time the interval [HallCnt of Hall count restrictions according to the brake weight of feedback _min, HallCnt _max];

Step 7: judge whether current Hall count value meets boundary limitation condition: if meet, this location information is effective; Otherwise, if HallCnt<HallCnt _min, make HallCnt=HallCnt _min; If HallCnt>HallCnt _max, make HallCnt=HallCnt _max;

Step 8: according to the power sensor Real-time Feedback value F collecting, calculate the slope F' of current brake weight:

$F^{\&prime;}=\frac{F\left(k\right)-F(k-M)}{M\&CenterDot;T}$

The power sensor sample value that wherein F (k) is current control cycle, F (k-M) is the power sensor sample value of a front M control cycle, T is the sampling time;

Step 9: if the slope of current brake weight feedback be on the occasion of, and piston direction is for negative, judgement piston is in anti-top state, stops immediately motor protection; Otherwise piston position state is normal, is back to step 4, proceeds position calculation.

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