Road surface detecting device for vehicle

• US 4,837,727 A
• Filed: 03/03/1986
• Issued: 06/06/1989
• Est. Priority Date: 03/04/1985
• Status: Expired due to Fees

• Current Assignee: Nippon Soken, Inc.
• Original Assignee: Nippon Soken, Inc.
• Inventors: Ina, Toshikazu, Tashiro, Syuzaburou, Kawai, Hisasi
• Primary Examiner(s): Chin, Gary
• Application Number:
  US06/835,883
• Time in Patent Office: 1,191 Days
• Field of Search: 364/550, 364/426, 364/551, 364/424, 364/565, 73/146, 73/105, 280/707, 33/551
• US Class Current: 702/167
• CPC Class Codes: B60G 17/019 characterised by the type of sensor or the arrangement thereof B60G17/01941 takes precedence
• CPC Class Codes: B60G 2500/10 Damping action or damper
• CPC Class Codes: B60G 2600/02 Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
• CPC Class Codes: B60T 2210/14 Rough roads, bad roads, gravel roads
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: F02D 2200/702 Road conditions
• CPC Class Codes: G01B 7/28 for measuring contours or curvatures

Abstract

A road surface detecting device has a rotary sensor for detecting the passage of teeth formed in an outer surface of a circular plate at regular intervals, which is connected to an axle of a vehicle and rotates thereabout, and generates an output signal pulsing every time when said teeth pass the rotary sensor. The output signal is inputted to a microcomputer. The microcomputer calculates period variations of the pulsing output signal and an average value of a predetermined number of the period variations. When the average value is not less than a predetermined value, the road surface is determined as being in a bad condition and when the average value is less than the predetermined value, the road surface is determined as being in a good condition; when the average value is less than the predetermined value and the most recently calculating period variation is not less than a predetermined period variation, the road surface is determined as being a rough area on a good road.

Claims

1. A road surface detecting device for detecting a condition of a road surface on which a vehicle runs, comprising:

(1) speed detecting means for detecting a speed of the vehicle at regular intervals of time;

(2) speed variation calculating means, coupled to said speed detecting means, for repeatedly calculating a speed variation between successively detected speeds of the vehicle;

(3) deviation calculating means for calculating a deviation between a predetermined number of said speed variations; and

(4) determining means for;

(a) determining the road surface as a bad condition when said deviation is not less than a predetermined value, and determining the road surface as a good condition when said deviation is less than said predetermined value and (b) determining the road surface as a rough area on a good road when said deviation is less than said predetermined value and a newest speed variation which has been most recently calculated is not less than a predetermined speed variation.

2. A road surface detecting device for detecting a condition of a road surface on which a vehicle runs, comprising:

(1) speed detecting means for detecting a speed of the vehicle at regular intervals of time;

(2) speed variation calculating means, coupled to said speed detecting means, for repeatedly calculating a speed variation between successively detected speeds of the vehicle;

(3) deviation calculating means for calculating a deviation between a predetermined number of said speed variations; and

(4) determining means for;

(a) determining the road surface as being a bad condition when said deviation is not less than a predetermined value, and determining the road surface as a good condition when said deviation is less than said predetermined value and (b) determining the road surface as a rough area on a good road when said deviation is less than said predetermined value, and a value obtained by dividing a newest speed variation, which has been most recently calculated, by said deviation is not less than a second predetermined value.

3. A road surface detecting device for a vehicle including a circular plate coupled to an axle of the vehicle to rotate with said axle, with a plurality of teeth around an outer periphery thereof, comprising:

(1) rotary sensor means, for detecting a passage of said teeth and outputting an output signal which has a transition in state every time one tooth passes said sensor means;

(2) variation calculating means for calculating a variation of a time between said transition in state of said output signal;

(3) deviation calculating means for calculating a deviation between successive ones of said variations calculated by said variation calculating means, wherein each said variation is a time difference between an integer number of complete rotations of said circular plate; and

(4) determining means for determining a road surface as a bad condition when the deviation is not less than a predetermined value and determining said road surface as a good condition when the variation is less than the predetermined value,

wherein said determining means determines the road surface as a rough area on a good road when said deviation is less than the predetermined value and a newest variation, which has been most recently calculated, is not less than a predetermined variation.

4. A road surface detecting device according to claim 3, wherein said deviation calculating means includes means for calculating an average value of said variations, and said determining means determines the road surface as said bad condition when the average value is not less than a predetermined average value and determines the road surface as said good condition when the average value is less than the predetermined average value.

5. An apparatus as in claim 3 wherein said deviation is a from the group consisting of an average of a plurality of said period variations and a standard deviation of said plurality of said period variations.

6. A device as in claim 3, said road surface detecting device further comprising said circular plate.

7. A road surface detecting device for a vehicle including a circular plate coupled to an axle of the vehicle to rotate with said axle, with a plurality of teeth around an outer periphery thereof, comprising:

(1) rotary sensor means, for detecting a passage of said teeth and outputting an output signal which has a transition in state every time one tooth passes said sensor means;

(2) variation calculating means for calculating a variation of a time between said transition in state of said output signal;

(3) deviation calculating means for calculating a deviation between successive ones of said variations calculated by said variation calculating means, wherein each said variation is a time difference between an integer number of complete rotations of said circular plate; and

(4) determining means for determining a road surface as a bad condition when the deviation is not less than a predetermined value and determining said road surface as a good condition when the variation is less than the predetermined value,

wherein said determining means determines the road surface as a rough area on a good road when both of (a) said deviation is less than the predetermined value and (b) a value obtained by dividing a newest variation, which has been most recently calculated, by said deviation, is not less than a second predetermined value.

8. A road surface detecting device for a vehicle comprising:

(1) speed detecting means for detecting a speed of the vehicle at regular intervals of distance;

(2) speed variation calculating means for repeatedly calculating a speed variation between successively detected speeds of the vehicle;

(3) average value calculating means for calculating an average value of a predetermined number of the calculated speed variations;

(4) frequency detecting means for detecting a number of times that said average value exceeds a predetermined average value in a predetermined travel distance; and

(5) determining means for determining a road surface as a bad condition when said number of times is not less than a predetermined number and determining the road surface as a good condition when said number of times is less than the predetermined number,

wherein said determining means determines the road surface as a rough area on a good road when said number of times is less than the predetermined value and a newest speed variation, which has been most recently calculated, is not less than a predetermined speed variation.

9. A road surface detecting device for a vehicle comprising:

(1) speed detecting means for detecting a speed of the vehicle at regular intervals of distance;

(2) speed variation calculating means for repeatedly calculating a speed variation between successively detected speeds of the vehicle;

(3) average value calculating means for calculating an average value of a predetermined number of the calculated speed variations;

(4) frequency detecting means for detecting a number of times that said average value exceeds a predetermined average value in a predetermined travel distance; and

(5) determining means for determining a road surface as a bad condition when said number of times is not less than a predetermined number and determining the road surface as a good condition when said number of times is less than the predetermined number,

wherein said determining means determines the road surface as a rough area on a good road when said number of times is less than a first predetermined value, and a value obtained by dividing the newest speed variation, which has been most recently calculated, by the average value, is not less than a second predetermined value.

10. A road surface detecting device for a vehicle including a circular plate connected to an axle of the vehicle so as to rotate about said axle, said circular plate having a plurality of teeth formed around an outer periphery thereof at regular intervals, comprising:

(1) a rotary sensor for detecting the passage of said teeth and outputting an output signal having a plurality of pulses, one pulse every time one tooth passes said rotary sensor;

(2) period variation calculating means for repeatedly calculating a variation of each period between said pulses of the output signal of said rotary sensor;

(3) average value calculating means for receiving a plurality of said variations, for an integer number of complete rotations of said circular plate, and for calculating an average value of the variations obtained in said integer number of complete rotations of said circular plate;

(4) frequency detecting means for detecting a number of times that said average value exceeds a predetermined average value in a predetermined running distance; and

(5) determining means for determining a road surface as a bad condition when said number of times is not less than a predetermined value and determining a road surface as a good condition when said number of times is less than the predetermined value,

wherein said determining means determines the road surface as a rough area on good roads when said number of times is less than a predetermined value and a newest period variation which has been most recently calculated is not less than a predetermined period variation.

11. A road surface detecting device for a vehicle including a circular plate connected to an axle of the vehicle so as to rotate about said axle, said circular plate having a plurality of teeth formed around an outer periphery thereof at regular intervals, comprising:

(1) a rotary sensor for detecting the passage of said teeth and outputting an output signal having a plurality of pulses, one pulse every time one tooth passes said rotary sensor;

(2) period variation calculating means for repeatedly calculating a variation of each period between said pulses of the output signal of said rotary sensor;

(3) average value calculating means for receiving a plurality of said variations, for an integer number of complete rotations of said circular plate, and for calculating an average value of the variations obtained in said integer number of complete rotations of said circular plate;

(4) frequency detecting means for detecting a number of times that said average value exceeds a predetermined average value in a predetermined running distance; and

(5) determining means for determining a road surface as a bad condition when said number of times is not less than a predetermined value and determining a road surface as a good condition when said number of times is less than the predetermined value,

wherein said determining means determines the road surface as a rough area on a good road when said number of times is less than a predetermined value and a value obtained by dividing a newest period variation which has been most recently calculated by the average value, is not less than a second predetermined value.

12. A road surface detecting device for detecting a condition of a road surface on which a vehicle runs, comprising:

(1) speed detecting means for detecting a plurality of indications related to speed of the vehicle, at least one indication being detected at regular intervals of time;

(2) speed variation calculating means for repeatedly calculating a speed variation between successively detected ones of said indications;

(3)deviation calculating means for calculating a deviation between a predetermined number of said speed variations; and

(4) determining means for determining the road surface as rough area on a good road when the deviation is less than a predetermined deviation and a newest calculated speed variation between a newest detected speed and its preceding detected speed is not less than a predetermined speed variation.

13. An apparatus as in claim 12 wherein said deviation is a calculation from the group consisting of (a) an average of a plurality of said variations and (b) a standard deviation of said plurality of variations.

14. A road surface detecting device for detecting a condition of a road surface on which a vehicle runs, comprising:

(1) speed detecting means for detecting an indication related to speed of the vehicle at regular intervals of time;

(2) speed variation calculating means for repeatedly calculating a speed variation between successively detected indications;

(3) deviation calculating means for calculating a deviation relation between a predetermined number of said speed variations; and

(4) determining means for determining the road surface as a rough area on a good road when the deviation is less than a predetermined deviation and a value obtained by dividing a newest calculated speed variation between a newest detected speed and its preceding detected speed by the calculated deviation is not less than a predetermined value.

15. An apparatus as in claim 14 wherein said deviation is a calculation from the group consisting of (a) an average of a plurality of said variations and (b) a standard deviation of said plurality of variations.

16. A road condition detecting device for detecting a condition of a road surface on which a vehicle is running, comprising:

means for detecting indications related to speed of said vehicle at first predetermined intervals of time; and

processing means for;

(1) determining accelerating of said vehicle based on said indications related to speed of said vehicle, said accelerations being determined at second intervals of time;

(2) calculating a deviation between a plurality of said accelerations, said deviation being a calculation from the group consisting of an average or a standard deviation of said plurality of accelerations;

(3) determining if a value indicative of said deviation is less than a predetermined threshold;

(4) determining if the most recently calculated acceleration is less than an acceleration threshold;

(5) determining said road which is being traversed as a rough spot on a good road when said deviation is less than said predetermined threshold and said most recently calculated acceleration is greater than said acceleration threshold;

(6) determining said road as a good road if said deviation is less than said predetermined threshold and said most recently calculated acceleration is less than said acceleration threshold; and

(7) determining said road as a bad road when said deviation is greater than said predetermined threshold.

17. A method for detecting a condition of a road surface, comprising the steps of:

detecting indications related to a speed of said vehicle at first regular intervals;

determining accelerations of said vehicle from ones of said indications related to speed of said vehicle at second regular intervals;

determining a deviation between a plurality of said accelerations;

determining if said deviation is less than a predetermined threshold;

determining if a most recently determined one of said accelerations is less than an acceleration threshold;

determining said road as a rough spot on a good road if said one of said accelerations is greater than said acceleration threshold and said deviation is less than said predetermined threshold;

determining said road as a good road if said deviation is less than said predetermined threshold and said acceleration is less than said acceleration threshold; and

determining said road as a bad road if said deviation is greater than said predetermined threshold.

18. A method as in claim 17 wherein said deviation is calculated as one of average or standard deviation of said plurality of accelerations.