CN103707870B - A kind of acquisition of piston position of aircraft electric brake actuator and guard method - Google Patents

Abstract

The present invention relates to a kind of acquisition and guard method of piston position of aircraft electric brake actuator; can in airplane brake system working process the location information of Real-time Obtaining piston; thus can actv. avoid actuator return to zero and dark anti-skidding time piston easily oppositely exert oneself and stuck problem, for the reliable and stable operation of Electric Brake System of Aircraft system provides strong support.

Description

A kind of acquisition of piston position of aircraft electric brake actuator and guard method

Technical field

The present invention relates to Electric Brake System of Aircraft system, be specially a kind of acquisition and guard method of piston position of aircraft electric brake actuator.

Background technology

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

All-electric braking system is the airplane brake system of new generation competitively developed 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 power of unloading compresses and leaves brake disc to realize by direct motor drive piston, electrical motor adopts the brushless direct current motor with three road hall position sensors usually.

Patent disclosed in current relevant aircraft electric brake actuator control aspect, with in the paper delivered, only utilizes the value of feedback of pressure sensor to carry out the control of brake weight usually, and pays close attention to this Important Parameters of actual position of piston is not too many.Although this processing mode can realize the function of basic electric brake, be but difficult to the precision and the reliability that ensure whole brake process.

Reason is mainly manifested in following two aspects:

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

(2) in brake process, when wheel enter dark anti-skidding time, require that actuator unloads power fast, make brake weight be zero, also require that piston and brake disc are close to simultaneously, can respond fast during to guarantee again to exert oneself.Because the collection of controller to pressure sensor feedback signal inevitably exists error, brake weight is made to be that zero given value is difficult to determine.If given value is bigger than normal, then cannot ensure that actuator is exerted oneself is zero; If less than normal, piston equally can be stuck in actuator because retreating always.

If the position of piston can be obtained, the feedback information of pressure sensor not only can be coordinated reliably to complete zeroing and deeply anti-skidding requirement, can also process in time the anti-failure condition pushed up of piston, achieve the defencive function for piston.This reliable and stable operation for airplane brake system has vital effect.

Summary of the invention

The technical matters solved

In order to avoid the deficiencies in the prior art part, the present invention proposes a kind of acquisition and guard method of piston position of aircraft electric brake actuator.

Technical scheme

The acquisition of the piston position of aircraft electric brake actuator and a guard method, is characterized in that step is as follows:

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

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

Wherein function f _minand f _maxexert oneself according to actuator and to be obtained by data fitting with the test data of piston position corresponding relation, F is the Real-time Feedback value of force snesor, F ₀for the preset value for piston zeroing location, span 500N ~ 1000N, N ₀the distance of piston and zero-bit when representing that pressure reaches preset value, value is determined by experimental debugging;

Step 2: after detecting that power circuit powers on, control plunger presses to brake disc until the signal of force snesor exports reach preset value F ₀, now give Hall counting machine HallCnt assignment N ₀;

Step 3: control plunger inverted running, often subtracts 1 through a Hall state Hall counting machine HallCnt, when Hall counting machine HallCnt is zero, stops motor and carries out zeroing process to the piston of actuator, making the gap keeping 3mm between piston and brake disc;

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

Step 5: when new state value NewState arrives, judge whether NewState equals NextState: if equal, then 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, then do not count, and the value of CurState remains unchanged;

Step 6: calculate Hall counting limit section [HallCnt in real time according to the brake weight of feedback _min, HallCnt _max];

Step 7: judge whether current Hall count value meets boundary limitation condition: if meet, then 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 force snesor Real-time Feedback value F collected, calculate the slope F' of current brake weight:

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

Wherein F (k) the force snesor sampled value that is current control period, F (k-M) for the force snesor sampled value of a front M control cycle, T be the sampling time;

Step 9: if the slope of current brake weight feedback be on the occasion of, and piston direction be negative, and judgement piston is in anti-dome-shaped state, and stopping motor being protected immediately; Otherwise piston position status is normal, is back to step 4, proceeds position calculation.

Beneficial effect

The acquisition of the piston position of a kind of aircraft electric brake actuator that the present invention proposes and guard method; can in airplane brake system working process the location information of Real-time Obtaining piston; thus can actv. avoid actuator return to zero and dark anti-skidding time 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

The acquisition of Fig. 1 piston position and guard method diagram of circuit

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

Detailed description of the invention

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 is formed primarily of the Moving plate that brakes, 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 set to 20kHz, and driving chip adopts IR2130.Control unit is powered by 28V, adopts TMS320F2812 as main control chip, utilizes the feedback signal of A and D converter to pressure sensor on its sheet to gather, utilize its trapping module to catch the three road signals that hall position sensor exports.

Step 1: macro definition F ₀be 800, represent and think piston and brake disc reliable contacts when force snesor value of feedback reaches 800N; Definition N ₀be 70, represent that piston needs inverted running 70 hall position states to reach zero-bit after contacting with brake disc, namely between piston and brake disc, keep the gap of about 3mm.Two parameters are debugged all by experiment and are determined.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, 0} stores the value of next hall position state when piston forward and inverted running.Counting machine HallCnt is initialized as 0.Store the piston position boundary limitation relational expression of exerting 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: after detecting that 160V has powered on, control plunger presses to brake disc until the signal of force snesor exports reach predetermined value F ₀, i.e. 800N, this hour counter HallCnt assignment is N ₀, namely 70;

Step 3: control plunger inverted running, often subtracts 1 through a Hall state counter HallCnt, until stop motor when being zero, stops motor and carries out zeroing process to the piston of actuator, making the gap keeping 3mm between piston and brake disc;

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

Step 5: when new state value NewState arrives, judge that whether NewState is equal with NextState.If equal, then HallCnt adds 1 or subtract 1 according to piston direction, and the value of NewState is assigned to CurState; If unequal, then 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: for the piston position obtained, judge whether to meet boundary limitation condition.If meet, then this location information is effective; Otherwise, if HallCnt<HallCntmin, make HallCnt=HallCntmin; If HallCnt>HallCntmax, make HallCnt=HallCntmax;

Step 8: the slope F' calculating force feedback signal according to the sampled value of force snesor:

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

Wherein F (k) the force snesor sampled value that is current control period, F (k-M) is the force snesor sampled value of a front M control cycle, and the sampling time, T was set to 2.5ms, and the sampling interval M often calculating a slope is 10;

Step 9: if slope be on the occasion of, and piston direction is negative, judges that piston is in anti-dome-shaped state, stops motor protecting immediately.Otherwise, show that piston position status 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 the need to other displacement pickups, just can obtain the position of piston more exactly, as shown in Figure 4;

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

(3) zeroing of piston accurately, is reliably realized, as shown in Figure 5;

(4) the piston position information obtained coordinate with force snesor can meet well dark anti-skidding time property indices, as shown in Figure 6.

Claims (1)

1. the acquisition of the piston position of aircraft electric brake actuator and a guard method, is characterized in that step is as follows:

Step 1: in the initialization of actuator control software design, next hall position state table HallForward [8] and HallBackward [8] when storage piston forward and inverted running respectively, described HallForward [8] and HallBackward [8] is one dimension variable HallForward [8]={ 0,5,3,1,6,4,2,0} and HallBackward [8]={ 0,3,6,2,5, Isosorbide-5-Nitrae, 0}, Hall counting machine HallCnt is initialized as 0, stores the piston position boundary limitation relational expression of exerting oneself corresponding with actuator:

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

Wherein function f _minand f _maxexert oneself according to actuator and to be obtained by data fitting with the test data of piston position corresponding relation, F is the Real-time Feedback value of force snesor, F ₀for the preset value for piston zeroing location, span 500N ~ 1000N, N ₀the distance of piston and zero-bit when representing that pressure reaches preset value, value is determined by experimental debugging;

Step 2: after detecting that power circuit powers on, control plunger presses to brake disc until the signal of force snesor exports reach preset value F ₀, now give Hall counting machine HallCnt assignment N ₀;

Step 3: control plunger inverted running, often subtracts 1 through a Hall state Hall counting machine HallCnt, when Hall counting machine HallCnt is zero, stops motor and carries out zeroing process to the piston of actuator, making the gap keeping 3mm between piston and brake disc;

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

Step 5: when new state value NewState arrives, judge whether NewState equals NextState: if equal, then 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, then do not count, and the value of CurState remains unchanged;

Step 6: calculate Hall counting limit section [HallCnt in real time according to the brake weight of feedback _min, HallCnt _max];

Step 7: judge whether current Hall count value meets boundary limitation condition: if meet, then 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 force snesor Real-time Feedback value F collected, calculate the slope F' of current brake weight:

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

Wherein F (k) the force snesor sampled value that is current control period, F (k-M) for the force snesor sampled value of a front M control cycle, T be the sampling time;

Step 9: if the slope of current brake weight feedback be on the occasion of, and piston direction be negative, and judgement piston is in anti-dome-shaped state, and stopping motor being protected immediately; Otherwise piston position status is normal, is back to step 4, proceeds position calculation.