公开(公告)号：JPH07329755A

公开(公告)日：1995-12-19

申请号：JP12652794

申请日：1994-06-08

Applicant: NIPPON DENSO CO

Inventor： MATSUURA MASAHIRO ,  OCHI TSUYOSHI ,  TERAO SHUSUKE

IPC: B60T8/58 ,  B60T8/172 ,  B60T8/1764

Abstract: PURPOSE:To provide a anti-skid control device capable of preventing the lowering of the reliability of an assumed road surface frictional coefficient. CONSTITUTION:When a speed difference of DELTAV1 or more is present between a rear wheel speed VWR and a front wheel speed VWF (after time t1), the calculation of assumed road surface frictional coefficient mu is already completed when the DELTAV1 is reached. Namely, its duration, i.e., the counted value by a timer counter TKeep is a duration (after time t1) passed after the road surface frictional coefficient is assumed lastly. Thus, when the duration is a specified time T2 or longer, even if the counted value is a proper assumed road surface frictional coefficient mu when it is calculated at a time t1, a long time is passed before it is used fox anti-skid control. Therefore a road surface frictional coefficient muS as a predetermined fixed value is set in place of the road surface frictional coefficient mu when a specified time T2 is continued (at the time t2). Thus an anti-skid control on safe side is assured.

公开(公告)号：JPH07165048A

公开(公告)日：1995-06-27

申请号：JP31197493

申请日：1993-12-13

Applicant: NIPPON DENSO CO

Inventor： MATSUURA MASAHIRO ,  OCHI TSUYOSHI ,  TERAO SHUSUKE ,  TSUNO TADAAKI

IPC: B60T8/1755 ,  B60T8/172 ,  B60T8/1761 ,  B60T8/58

Abstract: PURPOSE:To facilitate the exact judgement of a running state in a device for judging the running state of a vehicle on a wheel speed difference signal by interposing a means for removing a low frequency signal component from a wheel speed difference signal between a speed difference signal forming means and a running state judging means. CONSTITUTION:Detection signals sent from electromagnetic pickup type wheel speed sensors 71 to 74 provided on each of wheels FL to RR are input into an electronic control circuit ECU, and the wheel speed signals of right and left front wheels are first obtained here, and left front wheel speed is subtracted from right front wheel speed to form right and left front wheel speed difference signal DELTAVx. Next a by-path filtering treatment is carried out to DELTAVx to remove a low frequency signal component from DELTAVx for converting it into DELTAVw. Next the obtained signal DELTAVw is compared with a set value DELTAVo, and in the case of DELTAVw>DELTAVo, a vehicle is judged to be in a turning state, and a ABS control mode is set to a turning mode. On the other hand, in the case of DELTAVw

公开(公告)号：JPH07159308A

公开(公告)日：1995-06-23

申请号：JP31045793

申请日：1993-12-10

Applicant: NIPPON DENSO CO

Inventor： MATSUURA MASAHIRO ,  MASAKI SHOICHI

IPC: G01N19/02 ,  B60R16/02 ,  B60T8/172 ,  B60T8/1763 ,  B60T8/58 ,  F02D29/02 ,  G01M17/02

Abstract: PURPOSE:To estimate a frictional coefficient between a road surface and a wheel with high accuracy by finding the average change grade of a wheel speed in which a change in the wheel speed of a front wheel and a rear wheel for a vehicle is smaller is found, comparing the change rate of a difference in the wheel speed between the front wheel and the rear wheel with a definite value, and computing the frictional coefficient on the basis of an average change grade immediately before it becomes a definite value or higher. CONSTITUTION:Speed signals from wheel speed sensors 71 to 74 are input to a processing unit ECU, and a wheel speed, an acceleration and a speed difference between a front wheel and a rear wheel are computed. Then, within a prescribed time, an average deceleration grade is computed regarding the wheel speed in which a change in the wheel speed of the front wheel and the rear wheel is smaller. The deceleration grade of the wheel speed in which a change in a speed is smaller immediately before the change rate of the integrated value of the front wheel and the rear wheel within a prescribed time exceeds a prescribed value corresponds to a vehicle-body deceleration VB. When WF and WR refer to the load of the front wheel and that of the rear wheel respectively, WB refers to the weight of a vehicle and (g) refers to the acceleration of gravity, the frictional coefficient of a road surface can be found on the basis of mu=-(VB/g)WB/(WF+WR).

公开(公告)号：JPH0495557A

公开(公告)日：1992-03-27

申请号：JP21455690

申请日：1990-08-13

Applicant: NIPPON DENSO CO

Inventor： KISHIMOTO MASASHI ,  MASAKI SHOICHI ,  MATSUURA MASAHIRO

IPC: B60T8/32 ,  B60T8/172 ,  B60T8/1763

Abstract: PURPOSE:To improve the extent of braking efficiency by calculating an amount of minimum driving pulse width irreducibly required for selecting the setting of braking pressure on the basis of a battery supply voltage and brake fluid temperature, and setting the driving pulse width of an actuator from this minimum driving width and a slip state. CONSTITUTION:An antiskid controller is provided with an actuator A selecting the setting of braking pressure for a wheel, and it outputs a drive voltage to be impressed on the actuator A from a control means C according to a slip state detected by a slip state detecting means B. In this case, it is provided with a battery supply voltage detecting means S and a brake fluid temperature detecting means E. In addition, a minimum driving pulse width calculating means, calculating a minimum driving pulse width of the driving voltage irreducibly required for selecting the setting of braking pressure on the basis of at least either of the detected supply voltage or brake fluid temperature, is installed in this control means C, while pulse width of the driving voltage is set up by a driving pulse width setting means G on the basis of the slip state and the minimum driving pulse width.

公开(公告)号：JPH0826089A

公开(公告)日：1996-01-30

申请号：JP16702294

申请日：1994-07-19

Applicant: NIPPON DENSO CO

Inventor： MATSUURA MASAHIRO ,  OCHI TSUYOSHI ,  TERAO SHUSUKE ,  MASAKI SHOICHI

IPC: B60T8/1769 ,  B60T8/172 ,  B60T8/1763 ,  B60T8/58 ,  B60T8/66

Abstract: PURPOSE:To carry out the antiskid control suitable for the traveling road surface of a vehicle on the basis of the estimated and corrected road surface muby estimating the road surface mu without using an addition sensor such as a G sensor, and properly correcting the road surface mu according to the change in the traveling condition of the vehicle such as turn and the transfer between the road surfaces. CONSTITUTION:The car body acceleration speed in the case where the integration value SIGMADELTAVx of the wheel speed difference DELTAVx between the front and rear wheels becomes over the car body longitudinal G determined value D1 is obtained as the longitudinal G of the car body (Step 200), and the lateral G of the car body is obtained from the integration value of the speed difference between the left and right wheels and the speed sum (Step 400). The synthesized G is calculated from the longitudinal G and the lateral G (Step 118). and allowing the synthesized G to correspond to the frictional coefficient of the traveling road surface of the vehicle, the limit deceleration speed Vdown of the car body speed and the limit acceleration speed Vup are obtained from the function of the frictional coefficient of the traveling road surface.

公开(公告)号：JPH07329760A

公开(公告)日：1995-12-19

申请号：JP12525594

申请日：1994-06-07

Applicant: NIPPON DENSO CO

Inventor： MATSUURA MASAHIRO ,  TSUNO TADAAKI ,  TERAO SHUSUKE

IPC: B60T8/66 ,  B60T8/172 ,  B60T8/1763

Abstract: PURPOSE:To execute anti-skid control properly on an iced road surface by accurately detecting that a traveling is made on the iced road surface. CONSTITUTION:Because the ultimate values of an assumed vehicle deceleration at times t1, t3, and t5 are increased gradually, pressure reducing output set processing is executed for T2 time. Also, because the maximum value of a wheel acceleration GW immediately after the execution is smaller than G2, a rise variation in wheel speed VW is not produced, and it is found that a vehicle is braked on an iced road surface. Because, at a time t8a, a target body speed far iced road VSICE is set at an assumed body speed VB, and the assumed body speed VB is re-set at a high value, the wheel speed VW is lowered immediately from a set pressure reducing reference according to the assumed body speed VB, and a braking hydraulic pressure is reduced controllably from a time t9. By this, the wheel speed VW is increased until a favorable slip ratio can be achieved. Thus the iced road surface is detected accurately, anti-skid control can be made suit for the control of the vehicle on the iced road surface, and a braking distance can be minimized.

公开(公告)号：JPH07329751A

公开(公告)日：1995-12-19

申请号：JP12260694

申请日：1994-06-03

Applicant: NIPPON DENSO CO

Inventor： MATSUURA MASAHIRO ,  OCHI TSUYOSHI

IPC: G01P3/56 ,  B60T8/1755 ,  B60T8/58 ,  B62D6/00

Abstract: PURPOSE:To provide an anti-skid control device in which a stable control is possible even in an anti-skid control during turning. CONSTITUTION:When the wheel speed VW2 of a right front wheel is smaller than the wheel speed VW1 of a left front wheel and also a difference in speed between the front and rear wheels is small, it is judged that a vehicle is in turning condition at a time of t20. Also a cumulative value SIGMADELTAVX of 20 times of right and left wheel speed differences DELTAVX is calculated until the time of t21 and, when a lateral acceleration GY is obtained, the pressure reducing reference set width SRe12 of the right front and right rear wheels set at an initial pressure reducing reference set width SRe1 is expanded by an amount of a pressure reducing reference correction value DELTASRe1, as shown by dashed lines. By this, for the pressure reducing reference set width SRe12 not expanded, the wheel speed VW2 is reduced more than a pressure reducing reference at a time of t22 and the pressure reducing control of a brake pressure (brake oil pressure) is executed. Thus, when it is expanded, a brake pressure is maintained even after the time t22, and thus it is prevented for a braking distance to be extended.

公开(公告)号：JPH07329756A

公开(公告)日：1995-12-19

申请号：JP12765994

申请日：1994-06-09

Applicant: NIPPON DENSO CO

Inventor： MATSUURA MASAHIRO ,  OCHI TSUYOSHI ,  TERAO SHUSUKE

IPC: B60T8/58 ,  B60T8/172 ,  B60T8/1764

Abstract: PURPOSE:To incorporate into an anti-skid control by obtaining a gentle variation of road surface frictional coefficient accurately and prematurely during the anti-skid control. CONSTITUTION:When T1 has passed for a pressure boosting control, the integrated value of an assumed vehicle speed-wheel speed SIGMADELTAVW is equal or more than DELTAV1, and T2 has passed in a condition that an assumed body acceleration GB is approx. VDOWN (t3), an assumed road surface frictional coefficient muis increased by a specified value mu1, and a deviation between the assumed road surface frictional coefficient mu and actual road surface frictional coefficient is corrected. Also an assumed body speed VB is corrected downward, anc a specified area (pressure reducing reference speed shown by chain double-dashed line) set according to the assumed body speed VB is corrected downward automatically. By this, the pressure boosting control of braking pressure is continued. However, unless the assumed body speed VB is corrected, a wheel speed VW lowers more than a pressure reducing reference speed at a time t4, pressure reducing control is entered, and a braking distance is unnecessarily extended. This device prevents such an event.

公开(公告)号：JPH07315194A

公开(公告)日：1995-12-05

申请号：JP11548794

申请日：1994-05-27

Applicant: NIPPON DENSO CO

Inventor： MATSUURA MASAHIRO ,  OCHI TSUYOSHI ,  TERAO SHUSUKE

IPC: B60T8/58 ,  B60T8/172 ,  B60T8/1764

Abstract: PURPOSE:To precisely grasp the change of a road surface friction coefficient during nonskid control and reflect it to the control. CONSTITUTION:Even if pressure intensification control of brake hudraulic pressure by nonskid control is carried out in the case of changing from a low friction coefficient to a high friction coefficient at a time t2, wheel velocity VW does not start lowering, and accordingly, the pressure intensification control is not readily finished. Consequently, in the case when the pressure intensification control continues for a specified period of time (t1-t3), the pressure intensification control which is quicker than ever is carried out for a specified period of time (t3-t4). In the case when decompression control is not started within a specified period of time (t3-t5) by this quick pressure intensification, it is cleared that a vehicle is moved to a road surface of the high friction coefficient high enough not to drop the wheel velocity VW even by the quick pressure intensification, and a specified high road surface friction coefficient muHi is set for an estimated road surface friction coefficient mu. Consequently, estimated car velocity VB shows behavior almost to actual car velocity, and thereafter, favourable nonskid control continues.

公开(公告)号：JPH07165047A

公开(公告)日：1995-06-27

申请号：JP31197393

申请日：1993-12-13

Applicant: NIPPON DENSO CO

Inventor： MATSUURA MASAHIRO ,  OCHI TSUYOSHI ,  TERAO SHUSUKE ,  TSUNO TADAAKI

IPC: B60T8/1755 ,  B60T8/172 ,  B60T8/1764 ,  B60T8/58

Abstract: PURPOSE:To accurately judge the turning state of a vehicle for improving the control ability of ABS control and TRC control by judging whether the vehicle is in the turning state or not on speed difference between two right and left wheels and that between two front and rear wheels. CONSTITUTION:A turning state judging device has a wheel speed detecting means M1 to detect each of the wheel speeds of the right and left front and rear wheels, and a right and left wheel speed difference computing means M2 computes a speed difference between the right and left wheels on each wheel speed detected by the wheel speed detecting means M1, and the front and rear wheel speed difference computing means M3 computes a speed difference between the front and rear wheels on each wheel speed detected by the wheel speed detecting means M1. A turning state judging means M4 judges whether a vehicle is in a turning state or not on the computed speed difference between the right and left wheels and that between the front and rear wheels. Namely, for instance in the case where both the speed difference between the right and left wheels and that between the front and rear wheels are more than a set value, the vehicle is judged to be in the turning state.