CN111976965A - Multi-wheel vehicle frame main landing gear aircraft brake control system and method - Google Patents
Multi-wheel vehicle frame main landing gear aircraft brake control system and method Download PDFInfo
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- CN111976965A CN111976965A CN202010654499.3A CN202010654499A CN111976965A CN 111976965 A CN111976965 A CN 111976965A CN 202010654499 A CN202010654499 A CN 202010654499A CN 111976965 A CN111976965 A CN 111976965A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C25/00—Alighting gear
- B64C25/32—Alighting gear characterised by elements which contact the ground or similar surface
- B64C25/42—Arrangement or adaptation of brakes
- B64C25/44—Actuating mechanisms
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/66—Electrical control in fluid-pressure brake systems
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/66—Electrical control in fluid-pressure brake systems
- B60T13/68—Electrical control in fluid-pressure brake systems by electrically-controlled valves
- B60T13/686—Electrical control in fluid-pressure brake systems by electrically-controlled valves in hydraulic systems or parts thereof
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C25/00—Alighting gear
- B64C25/32—Alighting gear characterised by elements which contact the ground or similar surface
- B64C25/34—Alighting gear characterised by elements which contact the ground or similar surface wheeled type, e.g. multi-wheeled bogies
- B64C25/36—Arrangements or adaptations of wheels, tyres or axles in general
Abstract
The invention belongs to the technical field of airplane wheel braking systems, and discloses an airplane braking system and method for a main undercarriage of a multi-wheel carrier.
Description
Technical Field
The invention belongs to the technical field of airplane wheel braking systems, and particularly relates to an airplane braking system and method for a main landing gear of a multi-wheel frame.
Background
The airplane wheel braking system is used for controlling and controlling the braking of the braking airplane wheel so as to shorten the landing sliding distance of the airplane, prevent the airplane wheel from slipping and dragging the tire to burst, ensure the control safety, reduce the tire abrasion as much as possible, prolong the service life of the aviation tire and improve the economy, the maintainability and the supportability. Under the condition that the airplane is not braked, the bonding force (physically called friction force) between the airplane wheels and the ground, namely the surface of a runway is very small, and after the airplane is braked, the bonding force (physically called friction force) of the airplane wheels is rapidly increased and is in direct proportion to the brake pressure (the braking intensity is expressed by the common braking weight of an outfield). The friction of the wheels caused by braking strongly decelerates the aircraft.
As known from ordinary physics, this force necessarily creates a moment to the aircraft center of mass that lowers the aircraft because of the landing gear height and the distance behind the aircraft center of gravity (center of mass) C of the main landing gear on which the brake wheels are mounted. The presence of the low head moment redistributes the nose landing gear and the main landing gear ground normal force, with the result that the nose landing gear ground normal force increases and the main landing gear ground normal force decreases. Therefore, under the same braking strength, the brake wheels on the main landing gear are easy to slip due to the reduction of the bonding coefficient, so that the action (pressure relief) of an anti-slip system is caused, namely, the anti-slip effect of brake head lowering moment coupling is achieved, the landing sliding distance of the airplane is correspondingly prolonged, and the tire wear is increased due to frequent slipping. In the sliding brake process, pitching motion of lowering and raising the head of the airplane is continuously carried out, stability in the landing process is damaged, and comfort of passengers is reduced.
This phenomenon is often not noticeable for aircraft with 1 braked wheel on each side of the rear three-point landing gear, such as fighter planes, because the landing gear has only a single wheel and is not contrastive. However, wear of the front and rear tires of an aircraft with landing gears having multiple wheels is readily apparent. Large aircraft are equipped with multiple wheels for distributed runway pressure, for example, frame landing gear is typically configured with two front and rear rows of brake wheels (4 brake wheels in total for 2 × 2), or three front and rear rows of brake wheels (6 brake wheels in total for 2 × 3). The left and right main landing gear wheels are steered by a forward drive or a copilot. The front pilot steps on a left brake pedal and a right brake pedal of the front pilot to respectively control wheels of the left landing gear and the right landing gear of the airplane to brake, the front pilot steps on a left brake pedal and a right brake pedal of the front pilot to respectively control the wheels of the left landing gear and the right landing gear of the airplane to brake, and the brake system brakes the wheels with high brake pressure when the front pilot and the front pilot operate simultaneously. In the braking process, the front undercarriage presses the ground more firmly due to the braking head-lowering moment, the main undercarriage releases the ground, the brake wheels on the main undercarriage easily slip, and particularly the rear wheels are far away from the center of gravity of the airplane and the performance is more obvious. As a result, the landing skid distance of the aircraft becomes longer, and the tires of the rear wheels wear more than those of the front wheels. Thus, a potential disadvantage of existing aircraft multi-wheel landing gear configurations is that the aircraft brakes are inefficient and the tires on the rear wheels wear more than the tires on the front wheels. The brake head lowering moment coupling anti-skid effect cannot be ignored. Active countermeasures are required to be provided for a multi-wheel large airplane and a high-position gravity center airplane so as to improve the use brake efficiency, reduce the abrasion of tires and improve the operation economy, the maintainability and the supportability.
Chinese patent publication No. 101052564a discloses a method and apparatus for improving braking performance of an aircraft when the aircraft is traveling on the ground, wherein a normal force of a strut of a front landing gear is used as a reference, and a negative lift force is generated by an elevator and a horizontal tail aerodynamic surface to counteract a low head moment caused by braking. The technical scheme has the defects that measures are not taken for the difference of the positions of the front row wheels and the rear row wheels, and the problem that the rear row wheels are easy to slip still exists; the efficiency of the control surface is sharply reduced along with the reduction of the sliding speed, the effect of regulating the braking low head moment by the negative lift force is poor, and the sliding braking performance of the airplane is not obviously improved.
Disclosure of Invention
The invention provides a method and a system for controlling multi-wheel braking of an airplane, aiming at overcoming the defects that the airplane is low in braking efficiency and the abrasion of a tire of a rear row wheel is larger than that of a front row wheel in the configuration of a multi-wheel undercarriage of the airplane in the prior art. The technical approach of the invention is as follows: in the high-speed section, the brake of the rear row wheels is weakened, the brake of the front row wheels is strengthened, so that the brake head-lowering moment is adapted to distribute the ground normal force of the front row wheels and the ground normal force of the rear row wheels, namely the normal force of the front row wheels is larger than that of the rear row wheels, the transitional slipping of the rear row wheels is reduced, and the aims of improving the brake efficiency of the airplane, shortening the slipping distance and reducing the tire wear of the rear row wheels are fulfilled.
In order to achieve the purpose, the invention is realized by adopting the following technical scheme.
The first technical scheme is as follows:
a multi-wheel carrier main landing gear aircraft brake control system comprises a left main landing gear and a right main landing gear, wherein the left main landing gear and the right main landing gear are symmetrically positioned on two sides of an aircraft longitudinal axis of an aircraft and behind a mass center of the aircraft; the left main undercarriage and the right main undercarriage respectively comprise 4 brake wheels, and the 4 brake wheels of the left main undercarriage form a left front row wheel and a left rear row wheel in a pairwise manner; every two 4 brake wheels of the right main landing gear form a right front row wheel and a right rear row wheel;
the control system includes: the control system comprises a control box, 8 wheel speed sensors, 8 electro-hydraulic servo valves, 2 hydraulic brake valves and 2 pressure sensors;
each brake wheel is provided with a wheel speed sensor;
the 8 electro-hydraulic servo valves are symmetrically arranged in wheel cabins at two sides of a longitudinal axis of the airplane, 4 electro-hydraulic servo valves are arranged in the wheel cabin at each side, and each electro-hydraulic servo valve controls one brake wheel;
the 2 hydraulic brake valves are symmetrically arranged below the cockpit bottom plates on two sides of the longitudinal axis of the airplane;
the 2 pressure sensors are symmetrically arranged on the brake port pipelines of the hydraulic brake valves on two sides of the airplane longitudinal axis of the airplane.
The first technical scheme of the invention has the characteristics and further improvements that:
(1) each speed sensor is provided with a mechanical interface and an electrical interface, and the mechanical interface is mechanically connected with the corresponding brake wheel and used for receiving the rotary motion transmitted by the brake wheel; the electrical interface is electrically connected with the control box and provides a wheel rotation speed voltage signal of the corresponding brake wheel to the control box.
(2) The hydraulic brake valve has three hydraulic interfaces: the system comprises an oil inlet, a brake port and an oil return port, wherein the oil inlet is connected with a pressure supply source pipeline of an airplane brake system, the brake port is connected with an oil inlet pipeline of an electro-hydraulic servo valve, and the oil return port is connected with an airplane oil return pipeline;
the hydraulic brake valve is operated by a driver stepping on a brake pedal.
(3) Each electro-hydraulic servo valve is a negative gain pressure servo valve, and each electro-hydraulic servo valve is provided with an electric interface and three hydraulic interfaces: the oil inlet, the brake port and the oil return port;
one electrical interface is electrically connected with the control box and receives brake and antiskid control current signals sent by the control box; the oil inlet is connected with a hydraulic brake valve pipeline; the brake port is connected with an oil inlet pipeline of a brake device of the brake wheel; the oil return port is connected with an aircraft oil return pipeline.
(4) The control box is installed in the aircraft rear equipment cabin and is a digital brake control box.
(5) The control box is provided with an electrical interface which is electrically connected with 2 pressure sensors, 8 wheel speed sensors and 8 electro-hydraulic servo valves respectively;
the control box is used for receiving brake pressure signals sent by 2 pressure sensors and wheel speed voltage signals sent by 8 wheel speed sensors and outputting brake and antiskid control current signals to 8 electro-hydraulic servo valves.
The second technical scheme is as follows:
a multi-carrier main landing gear aircraft brake control method, which is applied to the control system according to the first technical scheme, and comprises the following steps:
collecting brake pressure;
generating a brake pressure control current according to the brake pressure;
collecting the sliding speed of the airplane;
determining a brake control current according to the airplane running speed;
outputting a brake control current and outputting brake control pressure according to the brake control current;
collecting the speed of the airplane wheel;
determining whether the wheel skids according to the speed of the wheel, and if so, generating antiskid control current;
outputting the integrated brake control current according to the brake control current and the antiskid control current;
and outputting anti-skid brake control pressure according to the integrated brake control current.
The second technical scheme of the invention has the characteristics and further improvements that:
(1) and determining a brake control current according to the plane running speed, specifically comprising the following steps:
when the airplane sliding speed is greater than or equal to the airplane sliding speed set value, the brake pressure control current is corrected, and the corrected current is used as the brake control current;
and when the airplane sliding speed is less than the airplane sliding speed set value, taking the brake pressure control current as the brake control current.
(2) When the airplane sliding speed is greater than or equal to the airplane sliding speed set value, the brake pressure control current is corrected, and the corrected current is used as the brake control current, and the method specifically comprises the following steps:
when the sliding speed of the airplane is greater than or equal to the sliding speed set value of the airplane, the brake control current of the front row wheel is greater than the brake control current of the middle row wheel, and the brake control current of the middle row wheel is greater than or equal to the brake control current of the rear row wheel.
(3) When P is more than or equal to PTAnd V is not less than VT，
Let I equal (0.15-0.30) IC
Wherein P is the brake pressure, unit Mpa, PTIs set value of brake pressure in MPa, and V is sliding speed of airplane in km/h and VTThe unit is km/h, I is brake control current, and the unit is mA and I is set value of the sliding speed of the airplaneCThe maximum rated current of the electro-hydraulic servo valve is in mA.
The invention provides a method and a system for controlling multi-wheel braking of an airplane. The technical approach of the invention is as follows: in the high-speed section, the brake of the rear row wheels is weakened, the brake of the front row wheels is strengthened, so that the brake head-lowering moment is adapted to distribute the ground normal force of the front row wheels and the ground normal force of the rear row wheels, namely the normal force of the front row wheels is larger than that of the rear row wheels, the transitional slipping of the rear row wheels is reduced, and the aims of improving the brake efficiency of the airplane, shortening the slipping distance and reducing the tire wear of the rear row wheels are fulfilled.
Drawings
FIG. 1 is a first structural schematic diagram of a multi-carrier main landing gear aircraft brake control system according to an embodiment of the invention;
FIG. 2 is a schematic structural diagram of a second aircraft brake control system for a main landing gear of a multi-carrier vehicle according to an embodiment of the invention;
FIG. 3 is a schematic flow chart of a method for controlling the braking of an aircraft with a multi-carrier main landing gear according to an embodiment of the invention;
the system comprises a hydraulic brake valve 1, a control box 2, an electro-hydraulic servo valve 3, a brake wheel 4, a wheel speed sensor 5, a pressure sensor 6, an FA-airplane heading, a C-airplane mass center, an x-x-airplane longitudinal axis, an L1-airplane left main landing gear and an L2-airplane right main landing gear.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.
See figure 1.
The embodiment of the invention provides a multi-wheel carrier main landing gear aircraft brake control system, as shown in figure 1, comprising: the hydraulic brake valve 1, the control box 2, the electro-hydraulic servo valve 3, the brake wheels 4, the wheel speed sensor 5, the pressure sensor 6 and the main landing gear are symmetrically arranged on two sides of an airplane longitudinal axis x-x of the airplane, and the quantity of each side is as follows: 1 hydraulic brake valve 1, 4 electro-hydraulic servo valves 3, 4 brake wheels 4, 4 wheel speed sensors 5, 1 pressure sensor 6, 1 main landing gear;
the main landing gear is a 4-wheel frame main landing gear with a strut positioned in the center of a frame, and comprises a left main landing gear L1 and a right main landing gear L2, wherein the left main landing gear and the right main landing gear are symmetrically positioned on two sides of an aircraft longitudinal axis x-x of the aircraft and behind an aircraft center of mass C. The terms of the left direction and the right direction are that an observer looks along the aircraft heading FA by taking the aircraft longitudinal axis x-x of the aircraft as a coordinate axis, the side where the left hand is located is the left side, and the side where the right hand is located is the right side. The "rear" heading term is defined as the orientation to which the observer faces toward the back of the aircraft FA along the longitudinal axis x-x of the aircraft with the origin of the coordinates of the center of mass C of the aircraft. Each 4-wheel frame main undercarriage is provided with 4 brake wheels 4, 2 brake wheels 4 are mounted on a front shaft to form a front row wheel, and 2 brake wheels 4 are mounted on a rear shaft to form a rear row wheel. The concept of the front row wheel or the rear row wheel is provided as the characteristic requirement of the brake control of the invention;
there are 8 wheel speed sensors 5 in total, one wheel speed sensor 5 being mounted on each brake wheel 4 of the left aircraft main landing gear L1 and the right aircraft main landing gear L2. The speed sensor 5 is provided with a mechanical interface and an electrical interface, wherein the mechanical interface is mechanically connected with the brake wheel 4 and receives the rotary motion transmitted by the brake wheel 4; the electrical interface is electrically connected with the control box 2 and provides a wheel rotation speed voltage signal of the brake wheel 5 for the control box;
the 2 hydraulic brake valves 1 are symmetrically arranged below the cockpit bottom plates on two sides of the airplane longitudinal axis x-x of the airplane, and 1 hydraulic brake valve 1 is arranged on each side. The hydraulic brake valve 1 is operated by a driver stepping on a brake pedal; the flight mode of the pilot, including forward piloting and copilot piloting, and the airplane forward piloting or copilot piloting to control the braking of the airplane wheels is according to the prior art;
the hydraulic brake valve has three hydraulic interfaces: the system comprises an oil inlet, a brake port and an oil return port, wherein the oil inlet is connected with a pressure supply source pipeline of an airplane brake system, the brake port is connected with an oil inlet pipeline of the electro-hydraulic servo valve 3, and the oil return port is connected with an airplane oil return pipeline;
specifically, an oil inlet of a left hydraulic brake valve 1 is connected with a pressure supply source pipeline of an airplane brake system, an oil return port of the left hydraulic brake valve 1 is connected with an airplane oil return pipeline, and brake ports of the left hydraulic brake valve 1 are respectively connected with oil inlet pipelines of 4 left electro-hydraulic servo valves 3;
an oil inlet of a right hydraulic brake valve 1 is connected with a pressure supply source pipeline of an airplane brake system, an oil return port of the right hydraulic brake valve 1 is connected with an airplane oil return pipeline, and a brake port of the right hydraulic brake valve 1 is respectively connected with oil inlet pipelines of 4 electro-hydraulic servo valves 3 on the right side;
the 2 pressure sensors 6 are symmetrically arranged on the brake port pipelines of the hydraulic brake valves 1 on two sides of the airplane longitudinal axis x-x of the airplane, and 1 pressure sensor 6 is arranged on each side.
The pressure sensor is provided with an electrical interface and a hydraulic interface, the hydraulic interface is connected with a brake port pipeline of the hydraulic brake valve 1, and the electrical interface is connected with an electrical interface of the control box 2;
specifically, a hydraulic interface of the left pressure sensor 6 is connected with a brake port pipeline of the left hydraulic brake valve 1, and an electrical interface of the left pressure sensor 6 is connected with an electrical interface of the control box 2;
a hydraulic interface of the right pressure sensor 6 is connected with a brake port pipeline of the right hydraulic brake valve 1, and an electrical interface of the right pressure sensor 6 is connected with an electrical interface of the control box 2;
the 8 electro-hydraulic servo valves 3 are symmetrically arranged in wheel cabins at two sides of an airplane longitudinal axis x-x of the airplane, and each side is provided with 4 electro-hydraulic servo valves 3. The left side 4 electro-hydraulic servo valves 3 are sequentially a left 1 electro-hydraulic servo valve 3, a left 2 electro-hydraulic servo valve 3, a left 3 electro-hydraulic servo valve 3 and a left 4 electro-hydraulic servo valve 3, and respectively control a front row wheel left brake wheel 5, a front row wheel right brake wheel 5, a rear row wheel left brake wheel 5 and a rear row wheel right brake wheel 5 of the left main landing gear L1 of the airplane. The right 4 electro-hydraulic servo valves 3 are a right 1 electro-hydraulic servo valve 3, a right 2 electro-hydraulic servo valve 3, a right 3 electro-hydraulic servo valve 3, a right 4 electro-hydraulic servo valve 3, a front row wheel left brake wheel 5, a front row wheel right brake wheel 5, a rear row wheel left brake wheel 5 and a rear row wheel right brake wheel 5 which respectively control the aircraft right main landing gear L2;
the electro-hydraulic servo valve 3 is a negative gain pressure servo valve. The electro-hydraulic servo valve 3 has one electrical interface and three hydraulic interfaces: the electric interface is electrically connected with the control box 2 and receives a control current signal sent by the control box 2; the oil inlet is connected with a pipeline of the hydraulic brake valve 1; the brake port is connected with an oil inlet pipeline of a brake device of the brake wheel 5; the oil return port is connected with an aircraft oil return pipeline;
the pressure current characteristic of the electro-hydraulic servo valve 3 negative gain pressure servo valve is that the torque motor coil of the electro-hydraulic servo valve 3 has no brake pressure output at the maximum rated current, the torque motor coil of the electro-hydraulic servo valve 3 outputs the maximum rated brake pressure when no current exists, and at the moment, the electro-hydraulic servo valve 3 is equivalent to a section of pipeline;
specifically, each electrical interface of the left 4 electro-hydraulic servo valves 3 is electrically connected with the control box 2 and receives a control current signal sent by the control box 2; each oil inlet of the left 4 electro-hydraulic servo valves 3 is connected with a brake port pipeline of the left hydraulic brake valve 1; each oil return port of the 4 electro-hydraulic servo valves 3 on the left side is connected with an airplane oil return pipeline;
each electrical interface of the right 4 electro-hydraulic servo valves 3 is electrically connected with the control box 2 and receives a control current signal sent by the control box 2; each oil inlet of the right 4 electro-hydraulic servo valves 3 is connected with a brake port pipeline of the right hydraulic brake valve 1; each oil return port of the 4 electro-hydraulic servo valves 3 on the right side is connected with an airplane oil return pipeline;
the control box 2 is mounted in the rear equipment bay of the aircraft. The control box 2 is a digital brake control box. The control box 2 has an electrical interface, which is electrically connected with 2 pressure sensors 6, 8 wheel speed sensors 5 and 8 electro-hydraulic servo valves 3, respectively, receives the brake pressure signal from the pressure sensor 1 and the wheel speed voltage signal from the wheel speed sensor 5, and outputs brake and antiskid control current signals to the electro-hydraulic servo valves 3. The power supply required by the control box 2 is provided by an aircraft power supply system;
the system of the present invention operates as follows. Taking a driving maneuver as an example:
the known full brake pressure is 10MPa, and the brake pressure set value P for intervening the brakeT6MPa, the maximum rated current of the electro-hydraulic servo valve is 40mA, and the set value V of the sliding speed of the airplaneTIs 100 km/h.
When the left and right brake pedals are fully stepped to the full brake during driving, the left and right hydraulic brake valves 1 mechanically connected with the driving brake pedal are operated by the brake pedal to output the full brake pressure of 10MPa, the pressure sensor 6 detects the pressure on the brake port pipeline of the hydraulic brake valve 1, and the detected pressure is detectedThe brake pressure voltage signal is supplied to the control box 2. The control box 2 collects a braking instruction sent by a driver, and the braking pressure P of the braking instruction is 10MPa and is greater than the braking pressure set value P for intervening brakingT6 MPa. At this time, whether the brake intervention is carried out on the rear row wheel or not needs to see the airplane speed when the airplane is braked. When the airplane is in a non-high-speed sliding stage, the brake intervention is not carried out on the rear row wheels, otherwise, the intervention is carried out, and the brake pressure of the rear row wheels is lower than that of the front row wheels. Now, if the speed of the airplane is 180km/h when the airplane lands, runs and brakes and is greater than the set value V of the sliding speed of the airplaneT100km/h, the control box 2 therefore regulates the brake pressure delivered to the rear wheels by the driver, and sends a control current I to the electrohydraulic servo valve 3 controlling the rear wheels, by a reduction of 20%, I ═ 0.20ICAnd (4) setting the brake pressure of the rear wheels to be lower than 20% of the brake pressure of the front wheels, namely setting the brake pressure of the rear wheels to be 8MPa and the brake pressure of the front wheels to be 10 MPa. Here ICThe current value is determined according to an electro-hydraulic servo valve current pressure characteristic equation of which P is 10MPa when I is 0mA and P is 0MPa when I is 40 mA.
The control box 2 outputs the formed brake control current to an electro-hydraulic servo valve 3 connected with a rear row wheel, specifically, a left 3 electro-hydraulic servo valve 3 and a left 4 electro-hydraulic servo valve 3 of 4 electro-hydraulic servo valves 3 on the left side, and a right 3 electro-hydraulic servo valve 3 and a right 4 electro-hydraulic servo valve 3 of 4 electro-hydraulic servo valves 3 on the right side obtain a brake control current signal 8mA, output brake pressure 8MPa, and respectively transmit the brake control current signal to a brake device of a left brake wheel 5 and a brake wheel 5 of a right brake wheel of a rear row wheel of an aircraft left main landing gear L1 and brake of a right brake wheel L2 of the aircraft;
in the process of airplane sliding and braking, if the airplane wheel slips, the control box 2 generates a corresponding anti-slip control current signal according to the sliding depth reflected by the airplane wheel speed voltage signal provided by the airplane wheel speed sensor 5, the brake control current signal input to the electro-hydraulic servo valve 3 and the anti-slip control current signal are integrated, the brake control current signal input to the electro-hydraulic servo valve 3 is increased, and the airplane wheel slip is relieved. The anti-slip control is carried out according to the prior art.
Compared with the prior art, under the condition, the landing and running on the dry cement runway, the sliding frequency of the rear wheels is reduced by 85%, the abrasion of the tires of the rear wheels is reduced by 75%, and the landing and running distance is shortened by 35%.
The embodiment of the invention is different from the above embodiment in that the number of the electro-hydraulic servo valves 3 is reduced by half, 2 electro-hydraulic servo valves 3 are respectively arranged on each side of the airplane, and one electro-hydraulic servo valve 3 controls a pair of brake wheels 4. The method comprises the following steps: a left 1 electro-hydraulic servo valve 3 on the left side of the airplane controls the front row wheel brake of a left main landing gear L1 of the airplane, and a left 2 electro-hydraulic servo valve 3 controls the rear row wheel brake of a left main landing gear L1 of the airplane; the right 1 electro-hydraulic servo valve 3 on the right side of the airplane controls the front row wheel brake of the right main landing gear L2 of the airplane, and the right 2 electro-hydraulic servo valve 3 controls the rear row wheel brake of the right main landing gear L2 of the airplane.
As shown in fig. 2, an aircraft multi-wheel braking system includes: the hydraulic brake valve 1, the control box 2, the electro-hydraulic servo valve 3, the brake wheels 4, the wheel speed sensor 5, the pressure sensor 6 and the main landing gear are symmetrically arranged on two sides of an airplane longitudinal axis x-x of the airplane, and the quantity of each side is as follows: 1 hydraulic brake valve 1, 2 electro-hydraulic servo valves 3, 4 brake wheels 4, 4 wheel speed sensors 5, 1 pressure sensor 6 and 1 main landing gear;
the main landing gear is a 4-wheel frame main landing gear with a strut positioned in the center of a frame, and comprises a left main landing gear L1 and a right main landing gear L2, wherein the left main landing gear and the right main landing gear are symmetrically positioned on two sides of an aircraft longitudinal axis x-x of the aircraft and behind an aircraft center of mass C. The terms of the left direction and the right direction are that an observer looks along the aircraft heading FA by taking the aircraft longitudinal axis x-x of the aircraft as a coordinate axis, the side where the left hand is located is the left side, and the side where the right hand is located is the right side. The "rear" heading term is defined as the orientation to which the observer faces toward the back of the aircraft FA along the longitudinal axis x-x of the aircraft with the origin of the coordinates of the center of mass C of the aircraft. Each 4-wheel frame main undercarriage is provided with 4 brake wheels 4, 2 brake wheels 4 are mounted on a front shaft to form a front row wheel, and 2 brake wheels 4 are mounted on a rear shaft to form a rear row wheel. The concept of the front row wheel or the rear row wheel is provided as the characteristic requirement of the brake control of the invention;
there are 8 wheel speed sensors 5 in total, one wheel speed sensor 5 being mounted on each brake wheel 4 of the left aircraft main landing gear L1 and the right aircraft main landing gear L2. The speed sensor 5 is provided with a mechanical interface and an electrical interface, wherein the mechanical interface is mechanically connected with the brake wheel 4 and receives the rotary motion transmitted by the brake wheel 4; the electrical interface is electrically connected with the control box 2 and provides a wheel rotation speed voltage signal of the brake wheel 5 for the control box;
the 2 hydraulic brake valves 1 are symmetrically arranged below the cockpit bottom plates on two sides of the airplane longitudinal axis x-x of the airplane, and 1 hydraulic brake valve 1 is arranged on each side. The hydraulic brake valve 1 is operated by a driver stepping on a brake pedal; the flight mode of the pilot, including forward piloting and copilot piloting, and the airplane forward piloting or copilot piloting to control the braking of the airplane wheels is according to the prior art;
the hydraulic brake valve has three hydraulic interfaces: the system comprises an oil inlet, a brake port and an oil return port, wherein the oil inlet is connected with a pressure supply source pipeline of an airplane brake system, the brake port is connected with an oil inlet pipeline of the electro-hydraulic servo valve 3, and the oil return port is connected with an airplane oil return pipeline;
specifically, an oil inlet of a left hydraulic brake valve 1 is connected with a pressure supply source pipeline of an airplane brake system, an oil return port of the left hydraulic brake valve 1 is connected with an airplane oil return pipeline, and brake ports of the left hydraulic brake valve 1 are respectively connected with oil inlet pipelines of 4 left electro-hydraulic servo valves 3;
an oil inlet of a right hydraulic brake valve 1 is connected with a pressure supply source pipeline of an airplane brake system, an oil return port of the right hydraulic brake valve 1 is connected with an airplane oil return pipeline, and a brake port of the right hydraulic brake valve 1 is respectively connected with oil inlet pipelines of 4 electro-hydraulic servo valves 3 on the right side;
the 2 pressure sensors 6 are symmetrically arranged on the brake port pipelines of the hydraulic brake valves 1 on two sides of the airplane longitudinal axis x-x of the airplane, and 1 hydraulic brake valve 1 is arranged on each side.
The pressure sensor is provided with an electrical interface and a hydraulic interface, the hydraulic interface is connected with a brake port pipeline of the hydraulic brake valve 1, and the electrical interface is connected with an electrical interface of the control box 2;
specifically, a hydraulic interface of the left pressure sensor 6 is connected with a brake port pipeline of the left hydraulic brake valve 1, and an electrical interface of the left pressure sensor 6 is connected with an electrical interface of the control box 2;
a hydraulic interface of the right pressure sensor 6 is connected with a brake port pipeline of the right hydraulic brake valve 1, and an electrical interface of the right pressure sensor 6 is connected with an electrical interface of the control box 2;
the 4 electro-hydraulic servo valves 3 are symmetrically arranged in wheel cabins at two sides of an airplane longitudinal axis x-x of the airplane, and 2 electro-hydraulic servo valves 3 are arranged at each side. The left side 2 electro-hydraulic servo valves 3 are sequentially a left 1 electro-hydraulic servo valve 3, a left 2 electro-hydraulic servo valve 3, a front row wheel left brake wheel 5, a front row wheel right brake wheel 5, a rear row wheel left brake wheel 5 and a rear row wheel right brake wheel 5 which respectively control the left main landing gear L1 of the airplane. The right 2 electro-hydraulic servo valves 3 are a right 1 electro-hydraulic servo valve 3, a right 2 electro-hydraulic servo valve 3, a front row wheel left brake wheel 5, a front row wheel right brake wheel 5, a rear row wheel left brake wheel 5 and a rear row wheel right brake wheel 5 which respectively control the aircraft right main landing gear L2;
the electro-hydraulic servo valve 3 is a negative gain pressure servo valve. The electro-hydraulic servo valve 3 has one electrical interface and three hydraulic interfaces: the electric interface is electrically connected with the control box 2 and receives a control current signal sent by the control box 2; the oil inlet is connected with a pressure source pipeline of an aircraft brake system; the brake port is connected with an oil inlet pipeline of a brake device of the brake wheel 5; the oil return port is connected with an aircraft oil return pipeline;
the pressure current characteristic of the electro-hydraulic servo valve 3 negative gain pressure servo valve is that the torque motor coil of the electro-hydraulic servo valve 3 has no brake pressure output at the maximum rated current, the torque motor coil of the electro-hydraulic servo valve 3 outputs the maximum rated brake pressure when no current exists, and at the moment, the electro-hydraulic servo valve 3 is equivalent to a section of pipeline;
specifically, each electrical interface of the left 2 electro-hydraulic servo valves 3 is electrically connected with the control box 2 and receives a control current signal sent by the control box 2; each oil inlet of the left electro-hydraulic servo valve 3 of the 2 electro-hydraulic servo valves is connected with a pressure source pipeline of an airplane brake system; left side 2 electro-hydraulic servo valves 3: the brake port of the left 1 electro-hydraulic servo valve 3 is respectively connected with oil inlet pipelines of brake devices of a left brake wheel 5 and a right brake wheel 5 of a front row wheel of a left main landing gear L1 of the airplane; the brake port of the left 2 electro-hydraulic servo valve 3 is respectively connected with oil inlet pipelines of brake devices of a left brake wheel 5 and a right brake wheel 5 of a rear wheel of a left main landing gear L1 of the airplane; each oil return port of the left 2 electro-hydraulic servo valves 3 is connected with an airplane oil return pipeline;
each electrical interface of the right 2 electro-hydraulic servo valves 3 is electrically connected with the control box 2 and receives a control current signal sent by the control box 2; each oil inlet of the 2 electro-hydraulic servo valves 3 on the right side is connected with a pressure source pipeline of an aircraft brake system; right 2 electro-hydraulic servo valves 3: the brake port of the left 1 electro-hydraulic servo valve 3 is respectively connected with oil inlet pipelines of brake devices of a left brake wheel 5 and a right brake wheel 5 of a front row wheel of a right main landing gear L2 of the airplane; the brake port of the right 2 electro-hydraulic servo valve 3 is respectively connected with the oil inlet pipelines of the brake devices of the left brake wheel 5 and the right brake wheel 5 of the rear row wheel of the aircraft right main landing gear L2; each oil return port of the 2 electro-hydraulic servo valves 3 on the right side is connected with an airplane oil return pipeline;
the control box 2 is mounted in the rear equipment bay of the aircraft. The control box 2 is a digital brake control box. The control box 2 has an electrical interface, which is electrically connected with 2 pressure sensors 6, 8 wheel speed sensors 5 and 4 electro-hydraulic servo valves 3, respectively, receives the brake pressure signal from the pressure sensor 1 and the wheel speed voltage signal from the wheel speed sensor 5, and outputs brake and antiskid control current signals to the electro-hydraulic servo valves 3. The power required by the control box 2 is provided by the aircraft power system.
The embodiment of the invention also provides an aircraft multi-wheel brake control method, as shown in fig. 3, including:
the method comprises the following steps of firstly, collecting brake pressure.
The brake pressure is provided by a pressure sensor.
And secondly, acquiring the speed of the airplane.
The aircraft speed is provided by a wheel speed sensor or by a flight parameter system on the aircraft.
Thirdly, determining the brake control current
When the brake pressure signals provided by the left undercarriage pressure sensor and the right undercarriage pressure sensor are collected, the control box determines whether to intervene the brake pressure of a driver according to the sliding speed of the airplane so as to adjust the brake pressure transmitted to the rear wheels. When the brake pressure is greater than or equal to the brake pressure set value and the airplane sliding speed is greater than or equal to the airplane sliding speed set value, the control box intervenes in the brake pressure of a driver to generate brake control current and reduce the brake pressure of the rear row wheels to enable the brake pressure of the rear row wheels to be lower than that of the front row wheels by 15-30%, and corresponding current is calculated by an electro-hydraulic servo valve current-pressure characteristic equation and is sent to an electro-hydraulic servo valve connected with the rear row wheels as the brake control current. The brake control current is determined as follows:
when P is more than or equal to PTWhen V is more than or equal to VT，
I＝(0.15-0.30)I C
In the formula, P-driver brake pressure, MPa
PTDriver brake pressure set value, MPa, PTIs 5-6.5MPa
V-airplane run speed, km/h
VTSet value of speed of taxiing, km/h, VTIs 95-120km/h
I-brake control Current, mA
I CMaximum rated current, mA, of electrohydraulic servo valve
It should be noted that the maximum rated current of the electro-hydraulic servo valve is different for different rated brake pressures, but the current value can be determined from the electro-hydraulic servo valve current pressure characteristic equation. If it is known that the current sent to the torque motor coil of the electro-hydraulic servo valve is zero, that is, if the electro-hydraulic servo valve outputs a brake pressure of P without anti-skid, then it is necessary to send a current to the torque motor coil of the electro-hydraulic servo valve to make the brake pressure output by the electro-hydraulic servo valve zero at the brake pressure, and at this time, the current sent to the torque motor coil of the electro-hydraulic servo valve is I, so that the brake pressure is P ═ 0, and the current is the maximum rated current I of the electro-hydraulic servo valveC。
These conditions do not allow for intervention correction of the pilot brake pressure in the absence of brake pressure or when the brake pressure is below a set value, or when the aircraft roll speed is less than the aircraft roll speed set value.
The control box is internally provided with an electro-hydraulic servo valve current-pressure characteristic curve.
And fourthly, outputting the brake control current.
The control box outputs the brake control current signal obtained in the fourth step to the electro-hydraulic servo valve.
And fifthly, outputting the brake control pressure.
The electro-hydraulic servo valve outputs the determined brake pressure to the brake wheel of the rear row wheel to brake after obtaining the brake control current, so that the brake pressure of the rear row wheel is 15-30% lower than that of the front row wheel.
And sixthly, collecting the speed of the airplane wheel.
The wheel speed is provided by a wheel speed sensor.
And step seven, generating an antiskid control current.
If the wheel is slipped, the control box generates a slip control current according to the wheel slip state. Otherwise, no antiskid control current is generated.
And step eight, outputting the integrated brake control current.
And the control box synthesizes the brake control current signal obtained in the fourth step and the antiskid control current signal generated in the eighth step, the brake control current of the front row of wheels is the antiskid control current, the brake control current of the rear row of wheels is the brake control current plus the antiskid control current, and the synthesized brake control current is output to the electro-hydraulic servo valve.
Ninth step, outputting antiskid brake control pressure
The electro-hydraulic servo valve obtains the integrated brake control current to output brake pressure to the brake wheel for braking, and the wheel skid is eliminated. For the front row wheels, the electro-hydraulic servo valve outputs brake pressure according to anti-skid control current and transmits the brake pressure to the front row wheel brake wheels for braking; for the rear row wheels, the electro-hydraulic servo valve outputs brake pressure according to the brake control current and the anti-skid control current and transmits the brake pressure to the rear row wheel brake wheels for braking;
although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (10)
1. A multi-wheel carrier main landing gear aircraft brake control system comprises a left main landing gear and a right main landing gear, wherein the left main landing gear and the right main landing gear are symmetrically positioned on two sides of an aircraft longitudinal axis of an aircraft and behind a mass center of the aircraft; the left main undercarriage and the right main undercarriage respectively comprise 4 brake wheels, and the 4 brake wheels of the left main undercarriage form a left front row wheel and a left rear row wheel in a pairwise manner; every two 4 brake wheels of the right main landing gear form a right front row wheel and a right rear row wheel;
characterized in that the control system comprises: the control system comprises a control box, 8 wheel speed sensors, 8 electro-hydraulic servo valves, 2 hydraulic brake valves and 2 pressure sensors;
each brake wheel is provided with a wheel speed sensor;
the 8 electro-hydraulic servo valves are symmetrically arranged in wheel cabins at two sides of a longitudinal axis of the airplane, 4 electro-hydraulic servo valves are arranged in the wheel cabin at each side, and each electro-hydraulic servo valve controls one brake wheel;
the 2 hydraulic brake valves are symmetrically arranged below the cockpit bottom plates on two sides of the longitudinal axis of the airplane;
the 2 pressure sensors are symmetrically arranged on the brake port pipelines of the hydraulic brake valves on two sides of the airplane longitudinal axis of the airplane.
2. A multi-carrier main landing gear aircraft brake control system according to claim 1,
each speed sensor is provided with a mechanical interface and an electrical interface, and the mechanical interface is mechanically connected with the corresponding brake wheel and used for receiving the rotary motion transmitted by the brake wheel; the electrical interface is electrically connected with the control box and provides a wheel rotation speed voltage signal of the corresponding brake wheel to the control box.
3. A multi-carrier main landing gear aircraft brake control system according to claim 1, wherein the hydraulic brake valve has three hydraulic ports: the system comprises an oil inlet, a brake port and an oil return port, wherein the oil inlet is connected with a pressure supply source pipeline of an airplane brake system, the brake port is connected with an oil inlet pipeline of an electro-hydraulic servo valve, and the oil return port is connected with an airplane oil return pipeline;
the hydraulic brake valve is operated by a driver stepping on a brake pedal.
4. A multi-carrier main landing gear aircraft brake control system according to claim 1,
each electro-hydraulic servo valve is a negative gain pressure servo valve, and each electro-hydraulic servo valve is provided with an electric interface and three hydraulic interfaces: the oil inlet, the brake port and the oil return port;
one electrical interface is electrically connected with the control box and receives brake and antiskid control current signals sent by the control box; the oil inlet is connected with a hydraulic brake valve pipeline; the brake port is connected with an oil inlet pipeline of a brake device of the brake wheel; the oil return port is connected with an aircraft oil return pipeline.
5. A multi-carrier main landing gear aircraft brake control system as claimed in claim 1, wherein the control box is mounted in the rear equipment bay of the aircraft, the control box being a digital brake control box.
6. A multi-wheeled vehicle frame main landing gear aircraft brake control system as claimed in claim 1, wherein said control box has an electrical interface for electrical connection to 2 pressure sensors, 8 wheel speed sensors and 8 electro-hydraulic servo valves, respectively;
the control box is used for receiving brake pressure signals sent by 2 pressure sensors and wheel speed voltage signals sent by 8 wheel speed sensors and outputting brake and antiskid control current signals to 8 electro-hydraulic servo valves.
7. A multi-carrier main landing gear aircraft brake control method for use in a control system according to any one of claims 1 to 6, the control method comprising:
collecting brake pressure;
generating a brake pressure control current according to the brake pressure;
collecting the sliding speed of the airplane;
determining a brake control current according to the airplane running speed;
outputting a brake control current and outputting brake control pressure according to the brake control current;
collecting the speed of the airplane wheel;
determining whether the wheel skids according to the speed of the wheel, and if so, generating antiskid control current;
outputting the integrated brake control current according to the brake control current and the antiskid control current;
and outputting anti-skid brake control pressure according to the integrated brake control current.
8. The method for controlling the braking of an aircraft with a main landing gear of a multi-wheel carrier according to claim 7, wherein the braking control current is determined according to the running speed of the aircraft, and specifically comprises:
when the airplane sliding speed is greater than or equal to the airplane sliding speed set value, the brake pressure control current is corrected, and the corrected current is used as the brake control current;
and when the airplane sliding speed is less than the airplane sliding speed set value, taking the brake pressure control current as the brake control current.
9. The method for controlling the braking of an aircraft with a multi-wheel carrier main landing gear according to claim 8, wherein when the aircraft sliding speed is greater than or equal to the set sliding speed value, the brake pressure control current is corrected, and the corrected current is used as the brake control current, specifically:
when the sliding speed of the airplane is greater than or equal to the sliding speed set value of the airplane, the brake control current of the front row wheel is greater than the brake control current of the middle row wheel, and the brake control current of the middle row wheel is greater than or equal to the brake control current of the rear row wheel.
10. The method of claim 9, wherein P is P ≧ PTAnd V is not less than VT，
Let I equal (0.15-0.30) IC
Wherein P is the brake pressure, unit Mpa, PTIs set value of brake pressure in MPa, and V is sliding speed of airplane in km/h and VTThe unit is km/h, I is brake control current, and the unit is mA and I is set value of the sliding speed of the airplaneCThe maximum rated current of the electro-hydraulic servo valve is in mA.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010654499.3A CN111976965A (en) | 2020-07-08 | 2020-07-08 | Multi-wheel vehicle frame main landing gear aircraft brake control system and method |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010654499.3A CN111976965A (en) | 2020-07-08 | 2020-07-08 | Multi-wheel vehicle frame main landing gear aircraft brake control system and method |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0342365A (en) * | 1989-07-11 | 1991-02-22 | Kayaba Ind Co Ltd | Brake system for aircraft |
| JPH08207726A (en) * | 1995-01-31 | 1996-08-13 | Mazda Motor Corp | Braking force control device for vehicle |
| CN106218871A (en) * | 2016-07-25 | 2016-12-14 | 西安航空制动科技有限公司 | Aircraft brake anti-skid control method and airplane brake system |
| CN109849881A (en) * | 2018-12-07 | 2019-06-07 | 西安飞机工业（集团）有限责任公司 | A kind of antiskid braking control system for airplane and control method |
| CN109963757A (en) * | 2016-08-24 | 2019-07-02 | 沃尔沃建筑设备公司 | Method for controlling the brake force of engineering machinery |
| CN212797296U (en) * | 2020-07-08 | 2021-03-26 | 西安航空制动科技有限公司 | Multi-wheel vehicle frame main undercarriage aircraft brake control system |
-
2020
- 2020-07-08 CN CN202010654499.3A patent/CN111976965A/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0342365A (en) * | 1989-07-11 | 1991-02-22 | Kayaba Ind Co Ltd | Brake system for aircraft |
| JPH08207726A (en) * | 1995-01-31 | 1996-08-13 | Mazda Motor Corp | Braking force control device for vehicle |
| CN106218871A (en) * | 2016-07-25 | 2016-12-14 | 西安航空制动科技有限公司 | Aircraft brake anti-skid control method and airplane brake system |
| CN109963757A (en) * | 2016-08-24 | 2019-07-02 | 沃尔沃建筑设备公司 | Method for controlling the brake force of engineering machinery |
| CN109849881A (en) * | 2018-12-07 | 2019-06-07 | 西安飞机工业（集团）有限责任公司 | A kind of antiskid braking control system for airplane and control method |
| CN212797296U (en) * | 2020-07-08 | 2021-03-26 | 西安航空制动科技有限公司 | Multi-wheel vehicle frame main undercarriage aircraft brake control system |
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