Obstacle detection method and system, particularly for systems for assisting the parking of vehicles

• US 20060087414A1
• Filed: 09/15/2005
• Published: 04/27/2006
• Est. Priority Date: 09/24/2004
• Status: Active Grant

• Current Assignee: META Systems (Siemens AG)
• Original Assignee: META Systems (Siemens AG)
• Inventors: Simonazzi, Giuseppe
• Granted Patent: US 7,385,487 B2
• Time in Patent Office: Days
• US Class Current: 340/435
• CPC Class Codes: G01S 15/931 of land vehicles
• CPC Class Codes: G01S 2015/932 for parking operations

Abstract

An obstacle detection system, particularly for assisting car parking that comprises a control unit and a plurality of sensors, which comprise emitters-receivers for emitting an ultrasonic signal and for receiving an echo signal reflected by at least one obstacle and an evaluator for the parametric evaluation of the received echo signals, the evaluator comprising a polling module suitable to determine, for each sensing, the number of times for which the received signals are repeated and to reject the signals that are repeated for a number of times that is lower than a preset number.

Claims

1. An obstacle detection system, comprising a control unit and a plurality of sensors, said sensors comprising:

signal emission means for emitting an ultrasonic signal and for receiving an echo signal reflected by at least one obstacle; and

parametric evaluation means for parametric evaluation of said received echo signal, said parametric evaluation means for parametric evaluation including polling means suitable to determine, for each sensing cycle, a number of times for which received signals are repeated and to reject signals that are repeated for a number of times that is lower than a preset number.

2. The obstacle detection system of claim 1, wherein said parametric evaluation means further comprise power driving means suitable to drive a power radiated by said signal emission means.

3. The obstacle detection system of claim 2, wherein said parametric evaluation means further comprise comparison means suitable to compare said echo signals received from said signal emission means with threshold values.

4. The obstacle detection system of claim 1, wherein said control unit is suitable to manage said sensors according to an order of priority.

5. The obstacle detection system of claim 4, comprising a single bus, said sensors being connected to said control unit by way of said single bus.

6. The obstacle detection system of claim 4, wherein said parametric evaluation means are suitable to determine values detected by said plurality of sensors that indicate, for each sensor, a distance between a respective sensor and the obstacle detected by the respective sensor.

7. The obstacle detection system of claim 6, wherein said control unit comprises memory means for storing said values that indicate the distance between said plurality of sensors and the detected obstacle.

8. The obstacle detection system of claim 7, wherein said order of priority for management of said plurality of sensors is determined according to said values that indicate the distance between said plurality of sensors and the detected obstacle.

9. An obstacle detection method, comprising the steps of:

a) for each sensor that belongs to an activation cycle, determining a power to be radiated, emitting corresponding ultrasound signals, and receiving echo signals reflected by at least one obstacle;

b) depending on the echo signals received, determining distances of corresponding sensors from the obstacle and amplifying the received echo signals according to corresponding distances;

c) selecting threshold values with which signals amplified according to said distances determined in step b) are to be compared; and

;

d) determining, at each sensing cycle, a number of times for which signals that exceed a respective selected threshold value are repeated, and, if said number is higher than a preset value, generating a warning signal.

10. The obstacle detection method of claim 9, further comprising the steps of:

e) determining an order of priority of the sensors according to the distances determined in step b);

f) determining an activation sequence of the sensors according to the order of priority determined in step e); and

g) adapting a sensing cycle of the sensors according to an activation sequence determined in step f).

11. The obstacle detection method of claim 10, wherein the sensing cycle adapted in step g) excludes, for a preset number of cycles that is greater than zero, sensors that in step a) have not received an echo signal.

12. The obstacle detection method of claim 11, wherein said step e) of determining the order of priority comprises the steps of:

associating with each sensor a value of the distance from the obstacle detected by the sensor;

determining a value that corresponds to a minimum detected distance and replacing said determined value with a value equal to a sum of said minimum distance value and of a priority threshold value; and

assigning to the sensor that detected said minimum distance a priority status.

13. The obstacle detection method of claim 12, wherein said step e) for determining the order of priority further comprises the steps that consist in:

at each sensing cycle, determining whether at least one of the detected distances is shorter than the sum of the minimum distance value and the priority threshold value; and

assigning to the sensor that detected said shorted distance a priority status in addition to sensors that already have a priority status.

14. The obstacle detection method of claim 13, wherein the sensing cycle adapted in step g) provides for the more frequent activation of the sensors having a priority status with respect to the sensors that do not have a priority status.