Ultrasonic measuring system

• US 5,491,648 A
• Filed: 01/28/1994
• Issued: 02/13/1996
• Est. Priority Date: 01/29/1993
• Status: Expired due to Fees

• Current Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Original Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Inventors: Aoki, Yasuyuki, Kuzuya, Keiji, Nakahara, Naoji
• Primary Examiner(s): Ramirez, Ellis B.
• Application Number:
  US08/187,507
• Time in Patent Office: 746 Days
• Field of Search: 364/565, 364/450, 364/426.01, 364/478, 364/559, 364/449, 364/822, 280/91, 280/96, 180/142, 180/143, 342/461, 342/106, 342/107
• US Class Current: 702/143
• CPC Class Codes: G01S 15/588 measuring the velocity vector
• CPC Class Codes: G01S 15/60 wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track
• CPC Class Codes: G01S 15/87 Combinations of sonar systems

Abstract

An ultrasonic measuring system detecting state informations of a vehicle other than a vehicle speed. An ultrasonic transducer TR1 directly detects the vehicle speed. A second ultrasonic transducer and a third ultrasonic transducer are disposed respectively in front of and at a back of a rotational center of the vehicle and separated from each other at a predetermined distance. They respectively transmit ultrasonic waves at right angles to the running direction of the vehicle and respectively at second and third predefined down-angles relative to the road. A two-dimensional speed of the vehicle can be measured on the basis of the speeds obtained by the transducers TR2 and TR3.

Claims

1. An ultrasonic measuring apparatus for a vehicle comprising:

a first ultrasonic transducer for transmitting ultrasonic waves to a road forwardly of the vehicle in a running direction of the vehicle and downwardly at a first predefined down-angle relative to the road, receiving reflected waves from the road and providing a first speed vector;

a second ultrasonic transducer and a third ultrasonic transducer, disposed respectively forwardly of and rearwardly of a rotational center of the vehicle and separated from each other at a predetermined distance, for respectively transmitting ultrasonic waves toward opposite sides of the vehicle respectively and at right angles to the running direction of the vehicle and respectively at second and third predefined down-angles relative to the road and receiving reflected waves from the road to provide second and third speed vectors; and

a calculating means for calculating a two-dimensional speed of the vehicle on the basis of the speed vectors obtained by the first, second and third ultrasonic transducers.

2. An ultrasonic measuring apparatus according to claim 1, in which the second ultrasonic transducer is disposed at a first fixed distance from the rotational center while the third ultrasonic transducer is disposed at a second fixed distance from the rotational center, the rotational center being disposed on a line connecting the second and third ultrasonic transducers.

3. An ultrasonic measuring apparatus according to claim 1, in which the first ultrasonic transducer is disposed at a center in a width direction of the vehicle.

4. An ultrasonic measuring apparatus according to claim 1, in which the second and third ultrasonic transducers are disposed at a center in a width direction of the vehicle.

5. A method, used in an ultrasonic measuring system for a vehicle composed of first, second and third ultrasonic transducers, comprising the steps of:

transmitting ultrasonic waves to a road, through the first ultrasonic tranducer forwardly of the vehicle in a running direction of the vehicle and downwardly at a first predefined down-angle relative to the road, receiving reflected waves from the road and providing a first speed vector;

transmitting ultrasonic waves, through the second and third ultrasonic transducers toward opposite sides of the vehicle respectively and which are disposed respectively forwardly of and rearwardly of a rotational center of the vehicle and separated from each other at a predetermined distance, at right angles to the running direction of the vehicle and respectively downwardly at second and third predefined down-angles relative to the road, receiving reflected waves from the road and providing second and third speed vectors; and

calculating a two-dimensional speed of the vehicle on the basis of said speed vectors obtained by the first, second and third ultrasonic transducers.