Vehicle for evaluating properties of road surfaces

• US 4,700,223 A
• Filed: 02/24/1986
• Issued: 10/13/1987
• Est. Priority Date: 06/07/1985
• Status: Expired due to Fees

• Current Assignee: Kokusai Kogyo Company Limited (Taiheiyo Cement Corporation)
• Original Assignee: Kokusai Kogyo Company Limited (Taiheiyo Cement Corporation)
• Inventors: Shoutaro, Kato, Tetsuo, Ogiwara, Tatsuhide, Nakane
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): Kostak, Victor R.
• Application Number:
  US06/832,126
• Time in Patent Office: 596 Days
• Field of Search: 358/93, 358/103, 358/106, 358/107, 358/113, 358/108, 358/96, 358/229, 358/903, 358/97, 358/102, 356/3, 356/4, 356/8, 356/11, 356/376
• US Class Current: 348/148
• CPC Class Codes: G01B 11/2522 the position of the object changing and being recorded
• CPC Class Codes: G01C 7/04 involving a vehicle which moves along the profile to be traced

Abstract

The invention provides a vehicle for evaluating the properties of road surfaces wherein a road surface cross-section profile evaluating means, a crack-evaluating means, and a road surface longitudinal profile evaluating means are mounted on a predetermined vehicle. The measuring intervals of the respective means can be controlled in accordance with a signal from a single speedometer/range finder. Three kinds of road surface property values which are matched with each other can be obtained. Even if the evaluation system (evaluation vehicle) and the object system (road surface) have a relative speed, the road surface property values can be accurately determined irrespective of the relative speed. Therefore, accurate and reliable evaluation data can be obtained, and the vehicle can cope with high speed and heavy traffic.

Claims

1. A vehicle for evaluating the properties of road surfaces, having a single speedometer/range finder, comprising:

(a) road surface cross-section profile evaluating means, having a CCD camera which is arranged at a rear or front portion of the evaluation vehicle and sensing a beam reflected from the road surface irradiated with a fan laser beam, said CCD camera sensing the reflected beam over a predetermined period of time based on a signal from the speedometer/range finder so as to form a matrix charge distribution on a light-receiving surface thereof by integration exposure corresponding to the sensing time, the matrix charge distribution being scanned in the road surface longitudinal section direction so as to obtain a peak exposure for each scanning line, and the road surface cross-section profile being formed in accordance with the peak value;

(b) road longitudinal section profile evaluating means, having three optical level meters which are mounted at equal intervals on a vehicle base parallel to the road surface so as to be in series in the travel direction of the vehicle and to correspond to a measuring pitch (l0) interval, a road surface radiation spot diameter of said optical level meters being set to be about 1 cm, distances to the road surfaces at three points corresponding to the measuring pitch (l0) being simultaneously measured for each measuring pitch (l0) based on a signal from the speedmeter/range finder, a temporary road surface level (Yi) and a temporary horizontal distance (Xi) at each measuring point having an evaluation start point (ai) and a first measuring point (bi) as temporary coordinates being obtained based on the evaluation data at the three points, and the temporary coordinates being converted into standard coordinates from the temporary road surface level (Yi) and the temporary horizontal distance (Xi) and the altitudes at two given points among the measuring points, thereby obtaining a road surface height (Hi) and a horizontal distance (Di) at each measuring point; and

(c) crack-evaluating means having a film camera which is arranged at a front or rear portion of the evaluation vehicle such that said film camera can sense in a direction perpendicular to the road surface, and a projector for projecting light in a direction at a predetermined angle with respect to an optical axis of said film camera, said film camera being capable of sensing the road surface at a film feed speed corresponding to a vehicle speed based on a signal from the speedometer/range finder.

2. A vehicle according to claim 1, wherein, in said longitudinal section profile evaluating means, said three optical level meters can evaluate a plurality of measuring points obtained by dividing the measuring pitch (l0) based on a signal from the speedometer/range finder, an average value of the data obtained at the plurality of measuring points being obtained as evaluation data at the three points corresponding to the measuring pitch (l0).

3. A vehicle according to claim 1, wherein, in said road surface cross-section profile evaluating means, an optical filter of the same color as the laser beam is mounted on said light-receiving surface of said CCD camera.