US3658388A - Anti-skid device - Google Patents

Anti-skid device Download PDF

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Publication number
US3658388A
US3658388A US72256A US3658388DA US3658388A US 3658388 A US3658388 A US 3658388A US 72256 A US72256 A US 72256A US 3658388D A US3658388D A US 3658388DA US 3658388 A US3658388 A US 3658388A
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Prior art keywords
output
adder
wheel
skid device
phase
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Expired - Lifetime
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US72256A
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English (en)
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Kiyoshi Hasegawa
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Toyota Motor Corp
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Toyota Motor Corp
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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
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/17—Using electrical or electronic regulation means to control braking
    • B60T8/176—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS
    • B60T8/1763—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS responsive to the coefficient of friction between the wheels and the ground surface
    • B60T8/17633—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS responsive to the coefficient of friction between the wheels and the ground surface based on analogue circuits or digital circuits comprised of discrete electronic elements

Definitions

  • Wheels of a running Vehicle con-51am is additionally PTOVided 303 21 A 313 21 with a second order phase-lead element whose constants are 51 Int. Cl.
  • the present invention proposes a method which eliminates the aforesaid defect and provides an improved control performance by additionally providing an anti-skid device with a simple control element.
  • the result of a control is fully sufficient to meet any road surface changes so that there is no need to alter the desired value or of the slip factor and the gain K of the control system, while at the same time an excellent control performance is achieved, since the amplitude of repetitive vibrations of the wheel acceleration and deceleration is small, resulting in a short stopping distance and good riding comfortability.
  • FIG. 1 is a slip factor-braking friction-coefficient characteristic curves
  • FIG. 2 is a block diagram of a conventional for maintaining the wheel slip factor constant
  • FIG. 3 is a block diagram equivalent to the block diagram of a conventional anti-skid device for maintaining the wheel slip factor constant
  • FIG. 4 is a diagram for explaining the open-loop transfer characteristics of a block diagram equivalent to the conven tional anti-skid device for maintaining the wheel slip factor constant;
  • FIG. 5 is a block diagram of an anti-skid device according to the present invention.
  • FIGS. 6, 7, 8, and 9 are diagrams showing the tests results.
  • FIG. 1 there is illustrated by way of example a slip factor a--braking friction coefficient ,ub characteristic curve in which a solid curve is the characteristic curve on a non-slippery road surface such as a dry asphalt road surface and a one-dot chain curve is a characteristic curve on the slippery road surface such as a frozen road surface.
  • 170 is the slip factor when the braking friction coefficient assumes the maximum value pbo
  • 0c is the desired value of the control system
  • #bc is the braking friction coefficient when the slip factor is ac.
  • FIG. 2 illustrates by way of example a block diagram of a conventional anti-skid device designed to maintain the wheel slip factor constant, and symbols P, V, and Vw in the figure represent the braking pressure, vehicle speed and wheel peripheral speed, respectively.
  • a slip factor setting means consists of a scale-factor element which produces (l 00/100)! through the multiplication of the vehicle speed V by a constant (1 00/100), an adder l is a comparator which compares the slip factor setting element anti-skid device output (1 a-c/lOO-V V and the wheel peripheral speed Vw, an electro-hydraulic servo is a pressure control circuit which employs a pressurepotentiometer to feed back the braking pressure converted into an electrical signal to an adder 2 so as to provide a stable braking force proportional to the output of an integrator, and the integrator is a control element which is combined 'with the pressure control circuit to form a driving element having integral characteristic of the first order.
  • FIG. 3 illustrates in terms of the transfer functions a block diagram of a constant slip factor anti-skid device equivalent in principle to the device of FIG. 2, with the motion of the wheel being limited within the region 0 rr 0'o of the slip factorbraking friction coefficient characteristic curve.
  • a transfer function K /(l T 8) is an approximate transfer function whenthe kinetic characteristic between the wheel and the road surface is evaluated with the input to a vehicle being the braking pressure P and the output being the slip factor 0', where K, is a gain constant showing the rate of occurrence of slip factor to the braking pressure, T is a time constant which represents the delay between the application of the braking pressure and the occurrence of the slip factor and S is a Laplace 's operator.
  • transfer function .s s (1 TzS) are approximate transfer functions derived from the other components in FIG. 2, that is, the first one K ,/5 corresponds to the transfer characteristics of the integrator, the second one to that of a power amplifier, a servovalve hydraulic cylinder, a master cylinder and a brake pipe, and the third one to that of the pressure potentiometer in FIG. 2, where K,, K;,, and K, designating their respective gain constants and T designating the time constant.
  • the open-loop transfer characteristics of FIG. 3 can be represented by the curves of again characteristic G, and phase characteristics I in FIG. 4, so that when road surfaces traveled by a vehicle change within the range between a slippery road surface such as a frozen road surface and a nonslippery road surface such as a dry asphalt road surface, the gain characteristic curve represented by the G, in FIG. 4 varies within the range G, 6",, whereas there is no change its phase characteristics.
  • the curves G, and G" are drawn for a case where the value of the ubo changes within the range of 10 times such as between 0.08 and 0.8.
  • the gain is adjusted such that the overshoot of the slip factor will be about 16 percent, that is, a good transient characteristic can be achieved when the vehicle is braked on a non-slippery road surface.
  • the phase margin becomes smaller and K4 t 3 Ti", l t Em AB, so that if the value of be is very small, as is the case on a frozen road surface, the phase margin becomes negative thereby making the system very unstable.
  • Such unstable repetitive vibrations of the wheels include vibrations attributable to the motion of the wheels entering into the range o-' o-o of the o'-p.b characteristic curve as is commonly known, in addition to the aforesaid vibrations caused by variations in the value of ubo. Explanation will be made hereunder of the case o'c o-o where the wheel motion comes into the range o' o'o without fail.
  • the desired value of the vehicle deceleration may be given as pbc 'g, the desired value of the wheel deceleration as 1- or) be -g,'and the desired value T of the wheel braking torque (proportional to the braking pressure) may be approximately expressed as T pbc 1R-W (l/R) where g is the acceleration by gravity; R is the radius of a wheel; W is the longitudinal load imposed on the wheel; and I is the moment of inertia of the wheel.
  • T represents a value which causes a slip factor o'c within the region oao, so that in order'that the wheel slip factor may be ac, it is necessary to first apply to the wheel a braking torque having a value larger than T so as to cause the motion of the wheel to fall within the region a' o'c and then to reduce the braking torque to the level of 7' Therefore, considering this fact in connection with the characteristics of the wheel motion by which once the wheel motion has entered into the region 0 0'C, even under the condition of o' oc, the reduction of braking pressure at any finite rate cannot cause the wheel peripheral speed to immediately turn towards the direction of its recovery, but it proceeds towards locking the wheel (Regarding 0', it is the direction towards the desired value), it is evident that the braking pressure reducing operation must be initiated before the slip factor 0' reaches the desired value or in order that the braking pressure and the slip factor may reach their respective desired values in an ideal manner.
  • a second order phase-lead element is indirectly provided by the composite circuit of an integrator and a phase-lead element of FIG. 5, so that the aforesaid pressure reducing operation is made possible by virtue of the predictive property of this element.
  • the acceleration and deceleration repetitive vibrations of the wheel under control represent a phenomenon characte rizing the dynamic characteristics of a control system, and thus the method of determining the constant of a compensating element with regard to such wheel vibrations constitutes a characteristic feature of the present invention.
  • the transfer function 00(8) of thesecond order phase-lead element is given by the resultant transfer function of the transfer function K IS of the integrator and the transfer function K (l T S)/(l 01 T 8) of the phase-lead compensating element and it may be expressed by the following equation:
  • the value of T is setto fallwithin the limits between (1l4rr) to (5/2'rr) times the period T of the acceleration and deceleration repetitive vibrations of the wheels under the controlled condition and the value of a is set to fall within the range between 0.1 and 0.4, while the value of K is set so that, when Kg, Ta, and a are substituted into the equations (1) and (2), w and i take such values which satisfy the relations 21r/T to 2'rr/5T and 0.1 s g l,respectively.
  • FIGS. 6 through 9 illustrate the test results, with FIGS. 6 and 7 showing the results of the running tests conducted on a non-slippery road surface and FIGS. 8 and 9 showing the results obtained on a slippery road surface.
  • These graphs illustrate the results of comparative tests conducted before and after the present invention was utilized to accomplish an improved performance.
  • the abscissae are a common time axis (T and the ordinates represent the braking pressure (P Kglcm wheel peripheral speed V... (Km/H) and .the vehicle speed V(Km/H), respectively.
  • the graphs showing the vehicle speed V, V is an imaginery curve showing the decelerating performance of the vehicle speed V obtained when wheels are locked; in one of the graphs shown in FIG. 6 which represents the wheel peripheral speed Vu, T, is
  • the desired value 00 of the slip factor is set to 20 percent
  • the gain constant K, of the integrator is set to 19.2 (volt/sec/volt)
  • the values of the gain constant K of the phase-lead compensating element, the time constant T, and a are set to 5.78 (volt/volt), 0.1 (sec) and 0.25, respectively.
  • the utilization of the present invention is effective in that an improved control performance is achieved by virtue of the fact that the control performance is not greatly influenced by road surface changes even if the desired value cc of the slip factor and the gain K of a control system are maintained constant, and hence a shorter stopping distance, a lower vibration level of the wheels during the braking operation and a comfortable ride can always be ensured.
  • An anti-skid device for vehicles comprising: a first adder for. comparing a value obtained by multiplying, through a slip factor setting means, the output of a vehicle speed detecting means by a coefficient smaller than unity and the output of a wheel peripheral speed detector; a second adder for comparing the output of a parallel combination of an integrator and a phase-lead compensating element, which are connected to the output terminal of said first adder, and the output proportional to the wheel braking pressure; and an electro-hydraulic driving element connected to the output terminal of said second adder and controlled by the output of said second adder to produce a wheel braking pressure to effect a predictive control so as to maintain the slip factor of the wheels constant.

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  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Regulating Braking Force (AREA)
US72256A 1969-11-12 1970-09-15 Anti-skid device Expired - Lifetime US3658388A (en)

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JP44090697A JPS5039232B1 (en)) 1969-11-12 1969-11-12

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Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3767272A (en) * 1970-09-23 1973-10-23 Teldix Gmbh Hydraulic brake system with anti-locking control
US4022513A (en) * 1972-04-12 1977-05-10 Crane Co., Hydro-Aire Division Selective deceleration brake control system
FR2431400A1 (fr) * 1978-07-21 1980-02-15 Honda Motor Co Ltd Dispositif de freinage sans derapage
US4799161A (en) * 1985-08-14 1989-01-17 Hitachi, Ltd. Control apparatus for maintaining traction in electric rolling stock
USRE33486E (en) * 1972-04-12 1990-12-11 Hydro-Aire Div. of Crane Company Selective deceleration brake control system
US5070459A (en) * 1987-10-15 1991-12-03 Robert Bosch Gmbh Anti-blocking and/or wheel slip regulating system
US20010002529A1 (en) * 1997-11-21 2001-06-07 Charles R. Cypher Building wall for resisting lateral forces
US20050126105A1 (en) * 2003-12-12 2005-06-16 Leek William F. Corrugated shearwall
US20050258785A1 (en) * 2002-08-29 2005-11-24 Toyot Jidosha Kabushiki Kaisha Device and method for controlling prime mover
US20050284073A1 (en) * 2003-12-12 2005-12-29 Leek William F Corrugated shearwall
US20060175997A1 (en) * 2002-08-29 2006-08-10 Akira Hommi Device and method for controlling prime mover
US20080296969A1 (en) * 2003-12-04 2008-12-04 Adnan Mustapha Arrangement for Influencing the Yawing Moment
US20110238221A1 (en) * 2010-03-25 2011-09-29 Yuji Kawazu Position control device
US8112968B1 (en) 1995-12-14 2012-02-14 Simpson Strong-Tie Company, Inc. Pre-assembled internal shear panel

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4336592A (en) * 1980-06-23 1982-06-22 Goodyear Aerospace Corporation Antiskid control system for brakes which exhibit large changes in lining friction coefficient
DE3306611A1 (de) * 1983-02-25 1984-08-30 Alfred Teves Gmbh, 6000 Frankfurt Verfahren und vorrichtung zur steuerung der bremskraftverteilung

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3005139A (en) * 1960-05-19 1961-10-17 Gen Electric Servosystem lead network
US3275384A (en) * 1966-01-10 1966-09-27 Crane Co Automatic brake control system
US3362757A (en) * 1964-06-16 1968-01-09 Hispano Suiza Sa Computer controlled wheel braking system
US3401984A (en) * 1967-01-24 1968-09-17 Henriette L Williams Vehicle brake control
US3433536A (en) * 1967-10-11 1969-03-18 Gen Motors Corp Regulated anti-lock braking system
US3467443A (en) * 1967-08-17 1969-09-16 Nippon Denso Co Antiskid apparatus for automotive vehicles
US3498682A (en) * 1967-09-05 1970-03-03 Eaton Yale & Towne Braking system

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3005139A (en) * 1960-05-19 1961-10-17 Gen Electric Servosystem lead network
US3362757A (en) * 1964-06-16 1968-01-09 Hispano Suiza Sa Computer controlled wheel braking system
US3275384A (en) * 1966-01-10 1966-09-27 Crane Co Automatic brake control system
US3401984A (en) * 1967-01-24 1968-09-17 Henriette L Williams Vehicle brake control
US3467443A (en) * 1967-08-17 1969-09-16 Nippon Denso Co Antiskid apparatus for automotive vehicles
US3498682A (en) * 1967-09-05 1970-03-03 Eaton Yale & Towne Braking system
US3433536A (en) * 1967-10-11 1969-03-18 Gen Motors Corp Regulated anti-lock braking system

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3767272A (en) * 1970-09-23 1973-10-23 Teldix Gmbh Hydraulic brake system with anti-locking control
US4022513A (en) * 1972-04-12 1977-05-10 Crane Co., Hydro-Aire Division Selective deceleration brake control system
USRE33486E (en) * 1972-04-12 1990-12-11 Hydro-Aire Div. of Crane Company Selective deceleration brake control system
FR2431400A1 (fr) * 1978-07-21 1980-02-15 Honda Motor Co Ltd Dispositif de freinage sans derapage
US4285042A (en) * 1978-07-21 1981-08-18 Honda Giken Kogyo Kabushiki Kaisha Antiskid brake device
US4799161A (en) * 1985-08-14 1989-01-17 Hitachi, Ltd. Control apparatus for maintaining traction in electric rolling stock
US5070459A (en) * 1987-10-15 1991-12-03 Robert Bosch Gmbh Anti-blocking and/or wheel slip regulating system
US9085901B2 (en) 1995-12-14 2015-07-21 Simpson Strong-Tie Company, Inc. Pre-assembled internal shear panel
US8112968B1 (en) 1995-12-14 2012-02-14 Simpson Strong-Tie Company, Inc. Pre-assembled internal shear panel
US20010002529A1 (en) * 1997-11-21 2001-06-07 Charles R. Cypher Building wall for resisting lateral forces
US20020002806A1 (en) * 1997-11-21 2002-01-10 Simpson Strong-Tie Company, Inc. Building wall for resisting lateral forces
US8479470B2 (en) 1997-11-21 2013-07-09 Simpson Strong-Tie Company, Inc. Building wall for resisting lateral forces
US8397454B2 (en) 1997-11-21 2013-03-19 Simpson Strong-Tie Company, Inc. Building wall for resisting lateral forces
US20060175997A1 (en) * 2002-08-29 2006-08-10 Akira Hommi Device and method for controlling prime mover
US7132806B2 (en) * 2002-08-29 2006-11-07 Toyota Jidosha Kabushiki Kaisha Motor control apparatus and motor control method
US7091678B2 (en) * 2002-08-29 2006-08-15 Toyota Jidosha Kabushiki Kaisha Device and method for controlling prime mover
US20050258785A1 (en) * 2002-08-29 2005-11-24 Toyot Jidosha Kabushiki Kaisha Device and method for controlling prime mover
US20080296969A1 (en) * 2003-12-04 2008-12-04 Adnan Mustapha Arrangement for Influencing the Yawing Moment
US8955923B2 (en) * 2003-12-04 2015-02-17 Knorr-Bremse Systeme Fuer Nutzfahrzeuge Gmbh Arrangement, method and device for influencing a yawing moment in a motor vehicle
US20100275540A1 (en) * 2003-12-12 2010-11-04 Simpson Strong Tie Co., Inc. Corrugated Shearwall
US20110197544A1 (en) * 2003-12-12 2011-08-18 Simpson Strong Tie Co., Inc. Corrugated shearwall
US8281551B2 (en) 2003-12-12 2012-10-09 Simpson Strong-Tie Company, Inc. Corrugated shearwall
US20050284073A1 (en) * 2003-12-12 2005-12-29 Leek William F Corrugated shearwall
US20050126105A1 (en) * 2003-12-12 2005-06-16 Leek William F. Corrugated shearwall
US20110238221A1 (en) * 2010-03-25 2011-09-29 Yuji Kawazu Position control device
US8452425B2 (en) * 2010-03-25 2013-05-28 Okuma Corporation Position control device

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JPS5039232B1 (en)) 1975-12-15
GB1320217A (en) 1973-06-13

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