GB2368649A - Rough road detector - Google Patents
Rough road detector Download PDFInfo
- Publication number
- GB2368649A GB2368649A GB0116037A GB0116037A GB2368649A GB 2368649 A GB2368649 A GB 2368649A GB 0116037 A GB0116037 A GB 0116037A GB 0116037 A GB0116037 A GB 0116037A GB 2368649 A GB2368649 A GB 2368649A
- Authority
- GB
- United Kingdom
- Prior art keywords
- rough road
- vehicle
- acceleration sensor
- time
- acceleration
- 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.)
- Granted
Links
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
- B60T8/1755—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve
- B60T8/17554—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve specially adapted for enhancing stability around the vehicles longitudinal axle, i.e. roll-over prevention
-
- 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
- B60T8/172—Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/18—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration in two or more dimensions
-
- 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
- B60T2210/00—Detection or estimation of road or environment conditions; Detection or estimation of road shapes
- B60T2210/10—Detection or estimation of road conditions
- B60T2210/14—Rough roads, bad roads, gravel roads
Landscapes
- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Regulating Braking Force (AREA)
- Vehicle Body Suspensions (AREA)
Abstract
A system for detecting the rough road running of a vehicle or the running of a vehicle with tyre chains. An output of an acceleration sensor (Sx) for sensing an acceleration in a running direction of a vehicle and an output of an acceleration sensor (Sy) for sensing an acceleration in a lateral direction perpendicular to the running direction are time-differentiated and, when absolute values of the time-differentiated values exceed a preset value, a rough road detection signal of rough road running is generated. A vehicle stability control device inhibits a zero point correction of the lateral acceleration sensor for a time period for which the rough road decision signal is generated.
Description
1 2368649
ROUGH ROAD DETECTOR
5 The present invention relates to a rough road detector for automatically detecting a state of a vehicle, which enters to a rough road, or a state of a vehicle, which is running with tire-chains attached to wheels thereof. Further, the present invention relates to a vehicle stability control device (vehicle attitude control device), which utilizes an output of the 10 rough road detector. The rough road detector according to the present invention can be utilized in not only the vehicle stability control device but also other control devices such as a suspension control device, a brake control device, etc., of a vehicle.
15 In an electronic vehicle control device such as ABS (Antilock Brake System) or VSC (Vehicle Stability Control), there may be a case where a control logic of the electronic vehicle control device mounted on a vehicle must be changed between cases where the vehicle is running on a smooth road such as a highway road and where the vehicle is running on a rough 20 road. In order to realize such change of control logic, JP H11241853 A assigned to the assignee of this application discloses a rough road detector for automatically detecting a state of a vehicle, which utilizes an acceleration sensor and is running on a rough road. In this prior art, an
operation logic for detecting the state of the vehicle running on a rough road 25 is disclosed, in which a dispersion of an output value of the acceleration sensor is logically operated for a certain time period by an operating circuit inputted with the output of the acceleration sensor and, when the
dispersion exceeds a predetermined value, the vehicle is decided as running on a rough road. Further, JP S60-2555 15 A (refer to FIG. 4 and its description, particularly) and
JP H08-995 16 A disclose an operation logic related to a vehicle suspension control, in 5 which a state of a vehicle running on a rough road is decided by utilizing an output of an acceleration sensor mounted on the vehicle.
The inventors of the present invention had found in performing various tests as to the above mentioned prior arts that a certain time is required to detect the rough road
running condition of the vehicle. That is, it is impossible, in the prior arts, to detect the
10 rough road condition of vehicle unless a vehicle runs on the rough road along a substantial distance. Further, the present inventors had found that, when an operating logic is changed to another in order to solve this problem, it becomes possible to detect the rough road runrung condition of a vehicle more precisely and more easily. Further, during the process ofthis test, the present inventors had studied as to an optimal change 15 of control logic of VSC when the rough road running condition of the vehicle is detected. The present invention is featured by that the rough road running condition of a vehicle is detected by a time-differentiation of an output of an acceleration sensor mounted on the vehicle. This is based on the fact that a time when an output signal of 20 the acceleration sensor is changed abruptly corresponds to a time when a vehicle running on a smooth road enters to a rough road. This fact has been confirmed experimentally by the present inventors.
That is, according to a first aspect ofthe present invention, a rough road detector comprises acceleration sensors (Sx and Sy) and a logic operation circuit (DIET) inputted with outputs of the acceleration sensors (Sx and Sy), wherein the logic operation circuit (DET comprises operation means for time-differentiating the output 5 values of the acceleration sensor (Sx and Sy) and generation means for generating a rough road detection signal when the time-differentiated value of one of the outputs of the acceleration sensors exceeds a preset value (So).
Symbols in parentheses above are reference symbols used in the accompanying drawings to facilitate an understanding of a construction of the present invention.
10 However, the present invention is not limited to that construction.
The present invention provides an operating logic of a rough road detector capable of easily and precisely deciding a rough road running condition of a vehicle.
The rough road detector is capable of precisely detecting a rough road running condition of a vehicle within a short time by not providing any new hardware to the 15 rough road detector but improving an operating logic thereof.
The present invention also provides a vehicle stability control device capable of avoiding inadequate behavior of a vehicle due to running on a rough road by adequately changing the control logic thereof when the rough road running condition of the vehicle is detected.
20 The vehicle stability control device is also capable of immediately changing the control logic thereof from one control logic to another when the rough road running condition of the vehicle is detected and returning the control logic to the one control logic when the vehicle passes over the rough road and enters to a smooth road.
Although it may be possible to use a single acceleration sensor, it is preferable to utilize an acceleration sensor for sensing acceleration in a running direction, that is, forward or backward moving direction ofthe vehicle, and a lateral acceleration sensor for sensing acceleration in a lateral, that is, left and right, direction of the vehicle. In S the latter case, the operation means includes means for logically operating the output values of the two acceleration sensors to obtain timedifferentiated values thereof and the generating means for generating the rough road detection signal preferably includes means for generating the rough road detection signal when an absolute value of at least one of the time-differentiated values exceeds the preset value.
10 In a driving test of a practical vehicle, it has been found that a small variation appears in an output of an acceleration sensor mounted on the vehicle when the vehicle enters into a rough road having a substantially irregular surface. From this fact, it has been found that an entry of a vehicle to a rough road can be detected exactly by not only monitoring a magnitude of acceleration of the vehicle but also monitoring a 15 variation of the magnitude of acceleration of the vehicle, that is, monitoring a time differentiated value of an output of an acceleration sensor mounted on the vehicle.
It is general that a vehicle equipped with a VSC includes both an acceleration sensor for sensing acceleration of vehicle in a running direction thereof and an acceleration sensor for sensing acceleration of vehicle in a lateral direction, that is, a 20 direction perpendicular to the running direction ofthe vehicle. Therefore, it is possible to construct a vehicle control system, which utilizes outputs of the both acceleration sensors for rough road detection to produce a rough road detection signal when an absolute value of a time-differentiated value of at least one of the outputs of the two
acceleration sensors exceeds a preset value. Such construction of the vehicle control system is advantageous in improving the sensitivity of rough road detection.
By providing, in the vehicle control system, persistent time determining means for determining a time period to for which the state in which the absolute value of the 5 time-differentiated value exceeds the preset value persists, it is possible to prevent the rough road detection signal from being frequently ON/OFF switched. The persistent time period tOcan be optimally selected according to characteristics of a vehicle control system, which utilizes the rough road detection signal.
According to a second aspect ofthe present invention, a vehicle stability control 10 device, which utilizes the rough road detector, is featured by comprising control terminating means for terminating a portion or whole portion of the control for a time period, which is a sum of a time for which the rough road detection signal is generated continuously and a predetermined time after the generation of the rough road detection signal is terminated. It is preferable that the control terminating means includes 15 inhibiting means for inhibiting a zero point correction control ofthe lateral acceleration of the vehicle.
That is, the vehicle stability control device detects an increasing acceleration in the lateral direction, that is, the left or right direction of the vehicle and brakes a portion of wheels ofthe vehicle such that the vehicle is automatically accelerated in a direction 20 opposite to the direction in which the acceleration is increased. An input signal among input signals supplied _ _
to the vehicle stability control device, which is mostly influenced when the vehicle is running on the rough road, is an output signal of the lateral acceleration sensor and such strong influence is caused mostly by that the zero point correction of the lateral acceleration sensor is not performed 5 appropriately during the rough road running of the vehicle. Since, according to the present invention in which the zero point correction control of the lateral acceleration sensor is temporarily stopped during the rough road running, it is possible to avoid the most inappropriate control, which occurs during the rough road running of the vehicle.
An embodiment of the present invention will be described with reference to the drawings, in which: FIG. 1 is a block diagram of an embodiment of the present invention; and 15 FIG. 2 is a flowchart showing an operation of the embodiment of the present invention.
A rough road detector according to an embodiment shown in FIG. 1 includes an acceleration sensor Sx mounted on a vehicle frame such that an 20 acceleration in a running direction, that is, a forward or backward running direction of a vehicle, is detected and a lateral acceleration sensor Sy also mounted on the frame such that acceleration in a lateral, that is, left or light direction of the vehicle is detected. Outputs of the acceleration sensors Sx and Sy are inputted to a logical operation circuit DET. An output of the 25 logical operation circuit DET is inputted to a vehicle stability control device VSC. In this embodiment, the logical operation circuit DET and the vehicle stability control device VSC are constructed within a single logic operation
circuit. A lateral acceleration information Sy, a vehicle speed information, a steeling information, a rotation information of respective wheels, an engine rotation information, a clutch state information and a change gear 5 information are taken in the vehicle stability control device VSC through an interface I/O. The vehicle stability control device VSC is constructed such that the latter outputs brake control signals for the respective wheels to a braking system (not shown) through the interface I/O.
Now, a control procedure for executing the rough road detection by 10 using the rough road detector constructed as mentioned above will be described. The output of the acceleration sensor Sx and the output of the lateral acceleration sensor Sy are time-differentiated, respectively, and it is decided whether or not absolute values of the time-differentiated values of the 15 outputs of the acceleration sensor Sx and Sy exceed a threshold value SO, respectively. When the absolute values are equal to or larger than the threshold value SO, the output signals of the acceleration sensor Sx and Sy become rough road detection signals. In this embodiment, the persistent time detection means comprises a low-pass filter having time constant to.
20 That is, the persistent time of the rough road is determined by passing the absolute value related to one of the acceleration sensor and not smaller than the threshold value SO through the low-pass filter. Since the logical operation circuit DET for performing the above operation is a digital circuit, the logical operation circuit DET performs a procedure similar to that in the 2B case where the output signal is passed through the low-pass filter having time constant to. When the persistent time is determined, a rough road flag indicative of the vehicle running on a rough road is raised.
The flag indicative of the vehicle running on the rough road is sent to the vehicle stability control device VCS and the zero point correcting operation of the lateral acceleration sensor Sy in the vehicle stability control device VSC is stopped during the time period for which the rough road flag 5 is raised.
The following is one of optimal examples of the preset value, which were obtained by experiments conducted for practical vehicles by the present inventors: 0.04G/O.Olsec = 4G/sec 10 where G is acceleration of gravity and the time constant to is 1 second.
The rough road detection signal of the logical operation circuit DET is taken in the vehicle stability control device VSC and the vehicle stability control device inhibits the zero point correction of the lateral acceleration sensor for the time period for which the rough road detection signal 15 continues.
As described hereinbefore, according to the present invention, it is possible to precisely detect the rough road running condition or the running with tire chains attached to the wheels, within a short time. By utilizing this detection of rough road running condition of a vehicle, it is possible to 20 prevent the vehicle stability control device from inadequately operating during the rough road running of the vehicle.
Claims (6)
1. A rough road detector comprising at least one acceleration sensor and a logical operation Cil'CUit supplied with an output of said acceleration sensor, 5 said logical operation circuit including means for timedifferentiating the output value of said acceleration sensor and means for generating a rough road detection signal when the time-differentiated value exceeds a preset value.
2. A rough road detector as claimed in claim 1, wherein said rough road 10 detector includes a first acceleration sensor for sensing acceleration of the vehicle in a vehicle running direction and a second acceleration sensor for sensing acceleration of the vehicle in a direction perpendicular to the vehicle running direction, said logical operation circuit includes means for time- differentiating output values of said respective first and second 15 acceleration sensors and said means for generating includes means for generating the rough road detection signal when an absolute value of at least one of the time-differentiated values exceeds the present value.
3. A detector as claimed in claim 1 or claim 2, wherein said logical operation circuit includes persistent time determination means for 20 generating the rough road detection signal when a time period for which the absolute value of the time-differentiated value exceeds the preset value becomes equal to a predetermined time to.
4. A rough road detector substantially as hereinbefore described with reference to the accompanying drawings.
5 5. A vehicle stability control device comprising a rough road detector as claimed in any of the preceding claims and means for terminating a portion or a whole portion
of the control operation for a time period for which the rough road detection signal is kept generated.
6. A vehicle stability control device as claimed in claim 5, further comprising means for inhibiting a zero point correcting control of said second acceleration sensor 5 in the control operation, which is terminated by said means for terminating.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000206761A JP2002019601A (en) | 2000-07-07 | 2000-07-07 | Rough road judging device |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB0116037D0 GB0116037D0 (en) | 2001-08-22 |
| GB2368649A true GB2368649A (en) | 2002-05-08 |
| GB2368649B GB2368649B (en) | 2004-05-12 |
Family
ID=18703641
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0116037A Expired - Fee Related GB2368649B (en) | 2000-07-07 | 2001-06-29 | Rough road detector |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP2002019601A (en) |
| DE (1) | DE10133168A1 (en) |
| GB (1) | GB2368649B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8405522B2 (en) | 2010-09-30 | 2013-03-26 | Ford Global Technologies, Llc | Lane departure haptic warning with compensation for road-caused vibration |
| US10744983B2 (en) * | 2016-04-22 | 2020-08-18 | Nissin Kogyo Co, Ltd. | Brake fluid pressure control device for vehicle |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005100206A (en) * | 2003-09-26 | 2005-04-14 | Toyota Motor Corp | Vehicle information processing apparatus, vehicle information processing method, and vehicle information processing system |
| DE10356378A1 (en) * | 2003-12-03 | 2005-06-30 | Continental Aktiengesellschaft | Method for controlling the function of an electronic driving stability program for a motor vehicle |
| KR100987076B1 (en) | 2005-09-08 | 2010-10-11 | 주식회사 만도 | Rough road detection method of vehicle stability control system |
| JP4415959B2 (en) * | 2006-03-15 | 2010-02-17 | トヨタ自動車株式会社 | Brake control device |
| FR2923012B1 (en) * | 2007-10-31 | 2009-11-20 | Peugeot Citroen Automobiles Sa | METHOD FOR DETERMINING A PROBABILITY OF PRESENCE OF SNOW CHAINS ON THE WHEELS OF A MOTOR VEHICLE, METHOD FOR LIMITING THE WHEEL STROKE OF A VEHICLE USING THE PREVIOUS METHOD AND SYSTEM FOR IMPLEMENTING THE SAME |
| JP5092818B2 (en) * | 2008-03-12 | 2012-12-05 | 日産自動車株式会社 | Vehicle travel control device |
| DE102015104379A1 (en) * | 2015-03-24 | 2016-09-29 | Jungheinrich Aktiengesellschaft | Truck with a controller and operating procedures for a truck |
| CN110689717A (en) * | 2018-07-05 | 2020-01-14 | 上海博泰悦臻网络技术服务有限公司 | Method for adjusting driving behavior and vehicle |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5619407A (en) * | 1979-07-27 | 1981-02-24 | Hino Motors Ltd | Recorder for car |
| US4657280A (en) * | 1983-10-27 | 1987-04-14 | Honda Giken Kogyo Kabushiki Kaisha | System for controlling the damping rate of a vehicle suspension |
| US5173858A (en) * | 1989-12-19 | 1992-12-22 | Mitsubishi Denki K.K. | Suspension control system for enhancing response characteristics of a vehicle body |
| US5375872A (en) * | 1991-05-17 | 1994-12-27 | Mitsubishi Denki Kabushiki Kaisha | Suspension control device |
| JP2001063544A (en) * | 1999-08-27 | 2001-03-13 | Hino Motors Ltd | Bad road judging device |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60244666A (en) * | 1984-05-21 | 1985-12-04 | Nissan Motor Co Ltd | Anti-skid controller |
| JP2669687B2 (en) * | 1989-04-11 | 1997-10-29 | 富士通テン株式会社 | Acceleration sensor abnormality detection device of anti-skid control device with acceleration sensor |
| JP2652984B2 (en) * | 1990-10-30 | 1997-09-10 | 三菱自動車工業株式会社 | Anti-skid brake control method |
| JP3019466B2 (en) * | 1991-04-25 | 2000-03-13 | トヨタ自動車株式会社 | Road friction coefficient detector |
| JPH06107202A (en) * | 1992-09-25 | 1994-04-19 | Mazda Motor Corp | Rear wheel steering device for vehicle |
| JPH07137624A (en) * | 1993-11-15 | 1995-05-30 | Nissan Motor Co Ltd | Antiskid control device |
| JPH09243346A (en) * | 1996-03-12 | 1997-09-19 | Unisia Jecs Corp | Road surface condition detecting device |
| JP3479210B2 (en) * | 1997-12-23 | 2003-12-15 | アイシン精機株式会社 | Unpaved road determination device, and anti-skid control device including the unpaved road determination device |
| JP3572920B2 (en) * | 1997-12-26 | 2004-10-06 | 三菱自動車工業株式会社 | Road surface friction coefficient estimation device for vehicles |
-
2000
- 2000-07-07 JP JP2000206761A patent/JP2002019601A/en active Pending
-
2001
- 2001-06-29 GB GB0116037A patent/GB2368649B/en not_active Expired - Fee Related
- 2001-07-07 DE DE2001133168 patent/DE10133168A1/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5619407A (en) * | 1979-07-27 | 1981-02-24 | Hino Motors Ltd | Recorder for car |
| US4657280A (en) * | 1983-10-27 | 1987-04-14 | Honda Giken Kogyo Kabushiki Kaisha | System for controlling the damping rate of a vehicle suspension |
| US5173858A (en) * | 1989-12-19 | 1992-12-22 | Mitsubishi Denki K.K. | Suspension control system for enhancing response characteristics of a vehicle body |
| US5375872A (en) * | 1991-05-17 | 1994-12-27 | Mitsubishi Denki Kabushiki Kaisha | Suspension control device |
| JP2001063544A (en) * | 1999-08-27 | 2001-03-13 | Hino Motors Ltd | Bad road judging device |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8405522B2 (en) | 2010-09-30 | 2013-03-26 | Ford Global Technologies, Llc | Lane departure haptic warning with compensation for road-caused vibration |
| US10744983B2 (en) * | 2016-04-22 | 2020-08-18 | Nissin Kogyo Co, Ltd. | Brake fluid pressure control device for vehicle |
Also Published As
| Publication number | Publication date |
|---|---|
| DE10133168A1 (en) | 2002-01-17 |
| GB2368649B (en) | 2004-05-12 |
| JP2002019601A (en) | 2002-01-23 |
| GB0116037D0 (en) | 2001-08-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20080629 |