JPH06329010A - Device for controlling anti-skid brake system - Google Patents

Abstract

PURPOSE:To prevent frequent generation, of skid, reduce the wear of tires, and reduce the braking distance by providing a reference skid speed setting means which variably sets the reference skid speed according to the side skid angle detected by a side skid angle detecting means. CONSTITUTION:In setting an appropriate reference skid speed Vr from the side skid angle beta, a calculation module 13 preliminarily stores the characteristic data on the relationship between various side skid angle beta and the appropriate reference skid speed Vr through the measurement by using the wheels in the form of the approximate curve 14, the map or the like. The appropriate reference skid speed Vr is calculated by the software using the digital control according to the preset schedule. A skid speed computing element 5 to compute the deviation of the skid speed to the reference skid speed Vr and a valve current controller 6 to set the current for controlling the valve of the brake, i.e., the valve current so that this deviation may be zero, i.e., the skid speed may be equal to the reference skid speed Vr, are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antiskid / brake system control device, and more particularly, it is useful for a fixed wing aircraft.

[0002]

2. Description of the Related Art FIG. 2 shows the configuration of a conventional fixed-wing aircraft braking system control device. As operation of the conventional brake system control apparatus shown in FIG. 2, reference slip velocity V _r of the maximum coefficient of friction between the wheel 1 and the road surface is obtained is constant, as shown in FIG. 3, the slip velocity V _s That airframe Only by controlling the valve control current of the brake, that is, the valve current, so that the difference between the speed and the wheel peripheral speed becomes the reference slip speed V _r ,
The brake pressure is controlled without any consideration for tire skidding.

In FIG. 3, this brake system control device includes a rotation speed sensor 2 which outputs a quasi-sine wave having a frequency proportional to the rotation speed of a wheel, which is provided on a wheel 1 of an airframe, and a frequency of this sensor output as a voltage. The F / V converter 3 for converting and outputting a signal proportional to the wheel peripheral speed, the reference speed calculator 4 for quasi-calculating the machine speed from the wheel peripheral speed, and the difference between the machine speed and the wheel peripheral speed, that is, Sliding speed reference sliding speed V
A slip speed calculator 5 for obtaining a deviation with respect to _r, so that the deviation becomes zero, that is, the slip speed V _s is a reference slip speed V
and a valve current controller 6 for setting the valve current so that _r becomes _r . Reference numerals 7 and 8 in FIG. 3 denote subtractors, and 9 denotes an amplifier. Also, S is the Laplace operator, K
₁ ~K ₉ is a constant, V _PBM if slow response of the signal for pressing the sudden pressure after brake pressure release, V _TR is the skid after brake pressure release has occurred, and continues to release the brake pressure Shows the signal for.

[0004]

[SUMMARY OF THE INVENTION Incidentally, as shown in FIG. 4, the slip rate at which the maximum friction coefficient can be obtained when skidding occurs rather than V _r, the process proceeds to V _r '. However, since the controller continues to control the slip velocity V _{s to} be V _r , when V _r > V _r ′, the unstable region (V
It means that it is controlled by _r '<V _s ). As a result, the following problems occur. (1) Skid occurs frequently. (2) Abnormal friction of the tire occurs due to skid. (3) The braking distance is increased due to skid.

An object of the present invention is to provide an anti-skid / brake system control device that solves the above-mentioned problems of the prior art.

[0006]

An anti-skid / brake system control device of the present invention that achieves the above object is a device for controlling a brake so that a difference between a body speed and a wheel peripheral speed is a reference slip speed. It is characterized by comprising a side slip angle detecting means and a reference slip speed setting means for variably setting the reference slip speed corresponding to the side slip angle detected by the side slip angle detecting means.

[0007]

In general, the relationship between the friction coefficient between the wheel and the road surface and the sliding speed is as shown in FIG. 3, and a certain sliding speed V _r
Is the maximum friction coefficient μmax. If this is related to the sideslip angle β of the machine body, that is, the angle β formed by the machine body X-axis (the direction in which the wheels are going to advance) and the machine body speed vector, the maximum friction coefficient μ′max is calculated as shown in FIG. Sliding speed V
change to _r ′. That is, when β = 0, the maximum friction coefficient μ
The slip velocity at which max was obtained was V _r , but β = β
_{When 1} ≠ 0, it changes to V _r ′. Therefore, by detecting the sideslip angle β and setting the reference slip speed from V _r to V _r ′, it is possible to perform control that always captures the maximum friction coefficient even when the sideslip angle β changes, and is stable. Since it is controlled in the area, frequent skids can be prevented. This reduces tire wear and braking distance.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. FIG. 1 shows an embodiment of an antiskid / brake system controller for a fixed-wing aircraft to which the present invention is applied.
In FIG. 1, a portion 10 surrounded by an alternate long and short dash line is a main portion for realizing the present invention, and in this embodiment, a control rule based on digital control rather than analog control is applied. That is, in this embodiment, the sideslip angle β is set to INS (Inertial Navigatio).
n Set: Inertial navigation device) and other sensors 11 installed on the fuselage
The side slip angle calculation module 12 calculates from this output information, and the reference slip speed calculation module 13 calculates an appropriate reference slip speed V _r from this side slip angle β, and the slip speed becomes V _r with this set value. Brake control.

When INS is used as the sensor 11,
The calculation module 12 receives the angle signals of the aircraft's pitch angle, roll angle, heading angle, and the INS velocity signal in the inertial coordinate system from the INS, and calculates the aircraft body weight velocity based on these information. From the X and Y components of, the angle β formed by the aircraft X axis (the direction in which the wheel is going to advance) and the aircraft velocity vector is determined as the sideslip angle. In addition,
The sensor 11 may be any sensor capable of outputting a signal necessary for calculating the sideslip angle β such as INS.

From this sideslip angle β, an appropriate reference slip velocity V
_When setting _r , the calculation module 13 measures the characteristic data of the relationship between the various sideslip angles β and the appropriate reference slip speed V _r using wheels in advance and holds them in the form of an approximate curve 14 or a map. Then, according to a preset schedule, an appropriate reference slip speed V _r is calculated on software by using digital control.

The reference slip velocity V _r thus obtained
The brake control using is similar to that of the conventional art shown in FIG. An F / V converter 3 for converting a frequency into a voltage and outputting a signal proportional to the wheel peripheral speed, a reference speed calculator 4 for quasi-calculating the vehicle speed from the wheel peripheral speed, and a reference slip speed for the slip speed. slip speed calculator 5 for obtaining the deviation with respect to V _r, as so that slip velocity deviation becomes zero is the reference slip velocity V _r, valve current control for setting a valve control current or valve current brake And a container 6. Reference numerals 7 and 8 in FIG. 1 denote subtractors,
Reference numeral 9 represents an amplifier. Also, S is a Laplace operator, K ₁ ~
K ₉ is a constant, V _PBM is a slow response signal for pressing abrupt pressure after the brake pressure is released, and V _TR is for continuously releasing the brake pressure when a skid is generated even after the brake pressure is released. Indicates a signal. Further, Lead in the controller 6 indicates that the brake pressure is released quickly.

[0012]

According to the present invention, since an appropriate reference slip speed is set according to the sideslip angle, the following effects can be obtained in a braking system for a fixed wing aircraft or the like. (1) Since the control in the unstable region is avoided, it is possible to prevent the frequent occurrence of skids. (2) As a result, local friction of the tire can be reduced. (3) Further, even when skidding occurs, the maximum friction coefficient can always be obtained, so that the braking distance can be shortened.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a conventional example.

FIG. 3 is a diagram showing a relationship between a friction coefficient and a sliding speed.

FIG. 4 is a diagram showing a relationship between a friction coefficient and a sliding speed in consideration of skidding.

[Explanation of symbols]

 1 Wheel 2 Wheel Speed Sensor 3 F / V Converter 4 Reference Speed Calculator 5 Sliding Speed Calculator 6 Valve Current Controller 7, 8 Subtractor 9 Amplifier 11 Sideslip Angle Detection Sensor 12 Sideslip Angle Calculation Module 13 Reference Slip Speed Calculation module

Claims (1)

[Claims] 1. A device for controlling a brake so that a difference between a body speed and a wheel peripheral speed becomes a reference slip speed, a sideslip angle detecting means, and a sideslip angle detected by the sideslip angle detecting means. An anti-skid / brake system control device comprising: a reference slip speed setting means for variably setting the reference slip speed.