GB2478368A - Anti-lock brake with piezo actuator and independent optical measurement of the instantaneous wheel velocity - Google Patents
Anti-lock brake with piezo actuator and independent optical measurement of the instantaneous wheel velocity Download PDFInfo
- Publication number
- GB2478368A GB2478368A GB1016791A GB201016791A GB2478368A GB 2478368 A GB2478368 A GB 2478368A GB 1016791 A GB1016791 A GB 1016791A GB 201016791 A GB201016791 A GB 201016791A GB 2478368 A GB2478368 A GB 2478368A
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- GB
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- Prior art keywords
- brake
- wheel
- vehicle
- slip
- much
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000005259 measurement Methods 0.000 title description 7
- 230000003287 optical effect Effects 0.000 title description 5
- 230000004044 response Effects 0.000 abstract description 10
- 230000003068 static effect Effects 0.000 abstract description 6
- 230000007704 transition Effects 0.000 abstract description 4
- 238000000827 velocimetry Methods 0.000 abstract description 2
- 230000001133 acceleration Effects 0.000 description 14
- 230000033228 biological regulation Effects 0.000 description 4
- 239000000725 suspension Substances 0.000 description 4
- 230000001427 coherent effect Effects 0.000 description 3
- 230000010354 integration Effects 0.000 description 3
- 208000003028 Stuttering Diseases 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000033001 locomotion Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 239000010426 asphalt Substances 0.000 description 1
- 238000005314 correlation function Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000036962 time dependent Effects 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
Classifications
-
- 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
- B60T8/17636—Microprocessor-based systems
-
- 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
- B60T8/1761—Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS responsive to wheel or brake dynamics, e.g. wheel slip, wheel acceleration or rate of change of brake fluid pressure
-
- 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
- B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
- B60T8/321—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration deceleration
- B60T8/329—Systems characterised by their speed sensor arrangements
-
- 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
- B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
- B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
- B60T8/36—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition including a pilot valve responding to an electromagnetic force
- B60T8/3615—Electromagnetic valves specially adapted for anti-lock brake and traction control systems
- B60T8/369—Valves using piezoelectric elements
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Fluid Mechanics (AREA)
- Electromagnetism (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Regulating Braking Force (AREA)
Abstract
A strong piezo-actuator is inserted between brake piston and back side of the brake pad and is included in a regular anti locking brake system's feedback loop normally acting only on the hydraulic brake pressure system. Furthermore a laser scanner velocimetry is proposed to achieve a more accurate measure of the vehicle speed or respectively the longitudinal and lateral (drift) speed of each wheel axis. Both concepts together should enable a feedback response time roughly of the order of 10 microseconds which is much shorter than the nowadays achievable 10 milliseconds response time of solely hydraulic brake force generating systems which should make the anti locking brake system much more effective. Upon emergency breaking a vehicle can be held much closer to the limit of the elastic slip regime of the wheel slip (static friction regime) where the highest deceleration can be reached just before the vehicle transitions into sliding friction wheel slip.
Description
Concept for a piezo-supported anti locking brake comprising a 1Otsec feedback response and an exact independent measurement of the instantaneous forward velocity of each wheel's axle
Introduction and problem:
For an anti locking brake the time constant of the braking force regulatorTs feedback control is an essential factor, as to how closely the braking force can be kept exactly at the static friction limit, i.e. just before the point where static friction would experience the transition into sliding friction and thus the friction coefficient would experience a discrete jump to a drastically lower value and thus the brake path of a vehicle, in particular a car or motorcycle or airplane, would be drastically extended. The smoother the road surface, the more critical this behaviour is and the more inaccurate this feedback control will work the longer its time constant is. This braking force point of maximum deceleration is located so to speak at the maximum of the range of the mere elastic wheel-"slip", i.e. at that point of the braking force, at which the tire rubber is maximally elastically deformed, i.e. at which the forward velocity of the wheelTs axle is already faster than the vehicle speed calculated from wheel revolutions per time and the undeformed wheel circumference, but the wheel is not yet sliding on the asphalt. In simple words, the read-out vehicle velocity from a calibrated speedometer during braking is slower than the actual forward velocity of the wheelsT axles and thus of the vehicle already in the static friction regime. The equivalent holds vice versa for acceleration phases and thus for the traction control. Once the tire rubber begins to slide, this difference in velocity between the value as read-out from the speedometer and the actual forward velocity of the wheelsT axles will discontinuously and drastically increase, until the wheels will lock up completely and the speedometer then will show zero speed of course.
Current anti lock brake regulators are realized purely hydraulic, such that the time constant of the feedback control is in the range of several 10 to 100 milliseconds. Thus it is obviously impossible, especially under the condition of black-ice or hard-packed snow (when the jump of the friction coefficient from static to sliding friction is particularly high), to maintain the feedback controlTs working point just at or just slightly before that transition as described above, where the elastic wheel slip (mere tire deformation) ends (i.e. the point of maximum braking deceleration) and the sliding wheel slip begins -the brake will thus "stutter" and there will be significant periods of time, during which the wheel will briefly lock up and the braking deceleration then will be significantly reduced due to the then much smaller sliding friction being in effect and the brake path will roughly double, as compared to the situation if the braking force could continuously be maintained at the static friction limit. Hereby it is assumed, that during each feedback control cycle, i.e. during each "stutter/cadence-pulse" the friction coefficient and thus the braking force roughly lies in the adverse sliding friction regime during half of such a cycle time.
The problem of a conventional anti-lock-brake is thus on one hand the comparatively slow feedback response time of the hydraulic anti lock braking system and on the other hand the inaccurate determination of the actual forward velocity of the wheel axis during deceleration or acceleration as well.
State of the art: Anti-lock-brakes nowadays are solely hydraulic, where, however, additional brake servo pumps put an brake fluid under excess pressure, especially to enable a traction control, but eventually, the braking force in an anti lock brake is controlled merely by opening of rapid valves which causes to release the brake force at single wheels in a pulsating manner, in order to prevent these wheels from extended locking and thus in order to achieve a left-right compensation -where the wheel with the least grip dominates though -of the braking deceleration and particularly thus to maintain the tractability of the vehicle. The response time of these valves is roughly in the millisecond range and the feedback response of the entire system is further slowed by the visco-elasticity of the brake fluid and since the system thus suffers phase shifts, the feedback response needs to have an integral gain, which causes a further retardation of the feedback response (time constant). This all sums up to quite a few 10 -100 milliseconds response time of the brake force's feedback control. "Break by wire1' -systems (EP1138564A2) are, however, already in preparation, but these concern only the side of the brake pedal, in order to eliminate the slightly disturbing vibration of the brake pedal during a braking phase when the anti-lock-brake feedback control regulation is active.
Furthermore, for measuring the actual velocity of the wheel's axle, only the usually not even calibrated speedometer and several acceleration sensors (accelerometers) are available.
Even a calibrated speedometer provides, as described above because of the "elastic wheel slip" a false (too small) value for the vehicle's velocity during braking; mathematical integration of the acceleration, which is provided by an acceleration sensor, in principle gives an exact value though, but this value is only as exact as the starting initial value as provided by the calibrated speedometer, which can only be measured accurately as long as the wheel turns (elastic and sliding) slip-free. This in turn only functions, if the wheel is momentarily almost let loose by the brake, in order to again be able to rotate slip-free momentarily, in order to again record an/another exact starting initial value for the integration of the accelerometer's signal. This release of the brake again extends the shortest achievable brake path significantly. Furthermore, even a calibrated speedometer can only be as accurate as the wheel diameter remains constant, which also is only approximately the case, since the tire rubber wears in time during driving.
Solution: Two essential changes on an anti locking break are planned in the present invention, in order to be able to reduce the braking distance significantly.
1. A measurement of the forward velocity of the 4 wheel axles shall be performed independently of the (calibrated) speedometer and independent of the acceleration sensors in the car: Underneath each of the 4 (half-) axles essentially an optical computer (laser-) mouse is to be installed, which is able to exactly record the momentary forward speed of each wheel axle. Even lateral drift can be recorded this way. The principle of operation is the recording of a 2-dimensional cross-correlation function of the minute road surface structural details which are migrating through the laser beam and cast a migrating shadow onto the detector. Repeatedly recorded is the quadrant detector signal as it varies in time during a certain time span delta t and this time-dependent signal is cross-correlated with the next signal-"train" in the consecutive time span delta t which is shifted by the infinitesimal time span 6t with respect to the first signal-"train". From the calibrated geometrical shift of the corresponding part of the distance on the road, by which the second signal-"train" has to be shifted, in order to obtain with the first signal-"train" the normalized Cross-correlation integral of almost 1 respectively to maximize the cross-correlation integral, divided by t, the instantaneous velocity can be obtained. Also a optical laser mouse primarily measures a velocity from which "only' by integration a position is computed. The optical PC-mouse has to be altered to that extent -since it cannot sit directly on the road surface -that laser diode and quadrant detector have to be mounted and adjusted, such that the signal reflected from the road surface can readily be recorded. Possibly a continuous re-adjustment is necessary, e.g. by tilting of the laser in such a way, that the quadrant detector always provides maximized sum-and minimized difference-signals. Instead of the quadrant detector also a 2-dimensional CCD-array can be read-out and then always 2 pictures between the time difference t are recorded, which are then shifted such that their cross-correlation (integral) comes to normalized 1 or is maximized respectively.
Instead of the cross-correlation of a quadrant detector signal also a 2-dimensional CCD-array can be used, in which all pixel detectors are connected in parallel and the frequency of a point shadow, i.e. a scatterer on the road surface, migrating across the CCD-array illuminated by the reflection from the road surface provides a signal proportional to the velocity of the vehicle. This frequency multiplied with the separation of the middle points of the pixels just results in the speed of the vehicle at a laser beam reflected vertically from the road surface. In principle, a complete 2-dimensional array would not be needed, one linear CCD-array in direction of the vehicle heading and another one perpendicular would be sufficient. Thereby, the size of the arrays has to be chosen such that the pixel distance roughly equals the size of the expected point shadow in the laser speckle spot on the detector. The array length has to be as large, as the expected mean separations of the point shadows caused by the road surface structures in the reflected laser speckle spot. Intelligent computer software could even solve the problem, if for instance two road surface structural details are migrating simultaneously through the CCD-array -in that case a roughly doubled frequency component would also be measured, which would initially lead to a falsely doubled vehicle speed, but for instance through real-time software-comparison with the speedometer and combined with the said cross-correlation method of above, the computer would recognize immediately this measurement error of a factor of 2, since the speedometer aberration is not that large.
For simplicity, initially customary but expensive commercial heterodyne laser surface velocimeter (Polytek Waldbronn, see also DD232360A1 and DE102008038642A1) shall be employed for the accurate vehicle velocity measurement, which somewhat more simply can reach the here required velocity and accuracy ranges.
Also the wheel circumferential speed shall be determined via such a laser scanning system for enhancing the accuracy of the wheel slip feedback control/regulation, for instance by means of a laser in the wheel house which scans the tire on its upper side, in order to eliminate the errors of the (calibrated) speedometer measurement due to varying wheel circumferences (different tires/rims, worn tires etc.).
The anti-locking-brake computer also will compare the that way measured wheel axle velocity relative to the road surface with the speedometer or with the equivalently optically measured wheel circumferential speed respectively, and at that brake force magnitude point, where the difference will begin to rise very steeply (or where its derivative will steeply, almost discontinuously jump up respectively, i.e. at that point at which the "elastic wheel slip1' will begin to transition into the sliding wheel slip, the computer will reduce the braking force until this difference will return to linear behavior with brake force magnitude again or until its derivative will have a plateau again respectively -but all this in the presently invented concept much faster and much more accurately than a solely hydraulic system Alternatively at each wheel suspension a x-y-z acceleration sensor is mounted, which upon braking measures the negative acceleration at each wheel, upon increasing the vehicle speed of course measures the positive accelerations. Hereby, the anti locking brake feedback control responds that way, that the deceleration in driving heading direction x is always kept as close as possible at its maximum value at each wheel, where for maintaining tractability of course that wheel dominates which is braking/decelerating the least. In a turn, however, the negative lateral acceleration is maximized, whenever the longitudinal deceleration in heading direction cannot be maximized. That means, in a turn, the feedback regulator will gradually release the break, either if the deceleration in heading direction x moves over its maximum value (and decreases again) or (logical or) the deceleration in lateral direction y. In the vertical z-direction, also the acceleration as well as the tilt of the wheel suspension is recorded, in order to achieve a "look-ahead-gain" for the digital feedback control, since at higher dynamical pressure of the wheel onto the road also higher braking decelerations are to be expected.
Alternatively, each of the 4 wheel suspensions possesses in x-and y-direction an additional counter bearing which ends into a piezoelectric pressure sensor (similar to a wheel balancing machine), which records the longitudinal and lateral acceleration forces; advantage would be a shorter response time as compared to the x-y-micro-electromechanical acceleration sensor. In z-direction again a acceleration sensor combined with a tilt sensor would be installed, in order to equivalently through a "look-ahead-gain" be able to further reduce the time constant of the feedback control.
For all velocimetry coherent or non-coherent illumination sources, instead of a visible laser, also -coherent or non-coherent -UV, visible, infrared, microwave or even ultrasound radiation sources can be used alternatively, which might be necessary as the undercarriage of the car might become covered with dirt from the road.
2. Between brake piston and back side of the brake pad a piezo-actuator disk or layer shall be introduced, which performs a fine and minute movement and fast braking force regulation. Such a piezo can generate the necessary force of kilo-Newton and over a Iim range of motion time constants of lOi.isec can be achieved. This fast and sensitive regulation shall additionally support the "normal" hydraulic anti-locking-brake and shall maintain the wheel deceleration much more accurate at the upper limit of the elastic wheel-slip. It is hereby noted, that two coupled feedback loops (hydraulic and piezo-mechanic brake force, the manipulated variable), which are acting upon and are regulating the same control parameter (i.e. the elastic wheel slip), are very difficult to master and have to be adjusted very precisely.
3. For the experienced driver, the slow and rougher hydraulic regulating anti-locking feedback control should have the option to be turned off, such that the driver himself can maintain the hydraulic braking force very close within the optimal regime just using the brake pedal or lever, now only supported by the piezo-anti-locking brake system, which can regulate much faster, than it ever would be possible with the foot on the brake pedal, or much faster than also a brake by wire system could ever realize with solely hydraulic brakes.
4. The same system can of course just like the normal anti lock brake system be used, in order to realize an electronic lane departure warning system and a traction control.
Especially the independent exact optical measurement of the forward and sideways velocity of the 4 wheel suspensions is of great advantage besides the faster brake force control at the single wheels.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1103641A GB2478423A (en) | 2010-03-04 | 2011-03-03 | Anti-lock brake with piezo actuator and independent optical measurement of the instantaneous wheel velocity |
DE102011013153A DE102011013153A1 (en) | 2010-03-04 | 2011-03-03 | Concept for a piezo-assisted anti-lock braking system brake with very fast control response with independent measurement of the current wheel speed |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102010010482A DE102010010482A1 (en) | 2010-02-22 | 2010-03-04 | Piezo-mechanical braking force controller for car, has thermal and electrical isolating pane including sapphire and inserted between brake lining-side electrode layer of piezo-pane and back part of brake lining |
Publications (2)
Publication Number | Publication Date |
---|---|
GB201016791D0 GB201016791D0 (en) | 2010-11-17 |
GB2478368A true GB2478368A (en) | 2011-09-07 |
Family
ID=43243573
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1016791A Withdrawn GB2478368A (en) | 2010-03-04 | 2010-10-06 | Anti-lock brake with piezo actuator and independent optical measurement of the instantaneous wheel velocity |
GB1103641A Withdrawn GB2478423A (en) | 2010-03-04 | 2011-03-03 | Anti-lock brake with piezo actuator and independent optical measurement of the instantaneous wheel velocity |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1103641A Withdrawn GB2478423A (en) | 2010-03-04 | 2011-03-03 | Anti-lock brake with piezo actuator and independent optical measurement of the instantaneous wheel velocity |
Country Status (2)
Country | Link |
---|---|
DE (1) | DE102011013153A1 (en) |
GB (2) | GB2478368A (en) |
Families Citing this family (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ITTO20130307A1 (en) | 2013-04-17 | 2014-10-18 | Itt Italia Srl | METHOD TO REALIZE A BRAKE ELEMENT, IN PARTICULAR A BRAKE PAD, SENSORIZED, SENSORED BRAKE PAD, VEHICLE BRAKE SYSTEM AND ASSOCIATED METHOD |
CN106662181B (en) | 2014-09-08 | 2020-01-17 | 意大利Itt有限责任公司 | Method for producing a sensor-equipped brake element, in particular a brake pad, and sensor-equipped brake pad obtained thereby |
US9939035B2 (en) | 2015-05-28 | 2018-04-10 | Itt Italia S.R.L. | Smart braking devices, systems, and methods |
ITUB20153709A1 (en) | 2015-09-17 | 2017-03-17 | Itt Italia Srl | DATA ANALYSIS AND MANAGEMENT DEVICE GENERATED BY A SENSORIZED BRAKE SYSTEM FOR VEHICLES |
ITUB20153706A1 (en) | 2015-09-17 | 2017-03-17 | Itt Italia Srl | BRAKING DEVICE FOR HEAVY VEHICLE AND METHOD OF PREVENTING BRAKE OVERHEATING IN A HEAVY VEHICLE |
ITUA20161336A1 (en) | 2016-03-03 | 2017-09-03 | Itt Italia Srl | DEVICE AND METHOD FOR IMPROVING THE PERFORMANCE OF A VEHICLE ANTI-LOCK AND ANTI-SLIP SYSTEM |
IT201600077944A1 (en) | 2016-07-25 | 2018-01-25 | Itt Italia Srl | DEVICE FOR DETECTION OF RESIDUAL BRAKING TORQUE IN A VEHICLE EQUIPPED WITH DISC BRAKES |
CN106208805B (en) * | 2016-08-16 | 2017-12-22 | 南京航空航天大学 | A kind of electrodeless deceleration device and its method of work |
IT201900015839A1 (en) | 2019-09-06 | 2021-03-06 | Itt Italia Srl | BRAKE PAD FOR VEHICLES AND ITS PRODUCTION PROCESS |
EP4086125A1 (en) * | 2021-05-06 | 2022-11-09 | Safran Landing Systems UK Ltd | Anti-lock braking system |
US20240241003A1 (en) | 2021-05-25 | 2024-07-18 | Itt Italia S.R.L. | A method and a device for estimating residual torque between the braked and braking elements of a vehicle |
CN114802153B (en) * | 2022-03-04 | 2023-08-01 | 湖北国际物流机场有限公司 | Emergency braking method and system for pilot vehicle of unmanned airplane at airport |
CN116279353B (en) * | 2023-05-18 | 2023-08-04 | 厦门金龙汽车新能源科技有限公司 | Control method for matching regenerative braking and braking anti-lock braking system of pure electric bus |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4705323A (en) * | 1985-06-14 | 1987-11-10 | Nippondenso Co., Ltd. | Brake control apparatus for vehicle |
US5067778A (en) * | 1990-11-19 | 1991-11-26 | Testardi David A | High performance anti-lock brake system for original equipment and after-market applications |
US6213564B1 (en) * | 1997-04-15 | 2001-04-10 | Face International Corp | Anti-lock brake system with piezoelectric brake actuator |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DD232360A1 (en) | 1984-07-13 | 1986-01-22 | Maxhuette Unterwellenborn | ARRANGEMENT FOR CONTACTLESS MEASUREMENT OF THE SPEED AND LENGTH OF MOVING SOLID BODIES |
DE10015714A1 (en) | 2000-03-29 | 2001-10-04 | Bayerische Motoren Werke Ag | Electromechanical vehicle braking system |
AU2003282387A1 (en) * | 2002-11-18 | 2004-06-15 | Nsk Ltd. | Axle unit with slip sensor and slip measurement method |
DE102008038642A1 (en) | 2007-08-16 | 2009-02-19 | Continental Teves Ag & Co. Ohg | System and method for stabilizing a motor vehicle |
-
2010
- 2010-10-06 GB GB1016791A patent/GB2478368A/en not_active Withdrawn
-
2011
- 2011-03-03 GB GB1103641A patent/GB2478423A/en not_active Withdrawn
- 2011-03-03 DE DE102011013153A patent/DE102011013153A1/en not_active Withdrawn
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4705323A (en) * | 1985-06-14 | 1987-11-10 | Nippondenso Co., Ltd. | Brake control apparatus for vehicle |
US5067778A (en) * | 1990-11-19 | 1991-11-26 | Testardi David A | High performance anti-lock brake system for original equipment and after-market applications |
US6213564B1 (en) * | 1997-04-15 | 2001-04-10 | Face International Corp | Anti-lock brake system with piezoelectric brake actuator |
Also Published As
Publication number | Publication date |
---|---|
GB201103641D0 (en) | 2011-04-13 |
DE102011013153A8 (en) | 2012-10-25 |
DE102011013153A1 (en) | 2012-03-29 |
GB201016791D0 (en) | 2010-11-17 |
GB2478423A (en) | 2011-09-07 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |