Method and apparatus for guided parking of a vehicle using ultrasonic position detection
First Claim
1. A method of positioning a vehicle within a defined space comprising the steps of:
- providing an ultrasonic sensor fixed at a predetermined reference location;
emitting ultrasonic energy signals within the defined space at periodic predetermined intervals and receiving echoes reflected by the vehicle while ignoring ultrasonic reflection artifacts from irrelevant off-axis objects close to the sensor;
sensing the proximity of the vehicle relative to the sensor as the vehicle enters the defined space; and
using the sensed proximity, indicating to a driver of the vehicle the proximity of the vehicle to the reference location thereby enabling the driver of the vehicle to position the vehicle within the defined space.
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Accused Products
Abstract
A sensing and indicating device is mounted at a fixed location and uses transmitted and reflected acoustic or electrical energy to determine the distance between the sensor and an approaching vehicle. The sensor provides visual and/or audible indication of the distance between the vehicle and the sensor. The driver of the vehicle uses that displayed or audible information to locate the vehicle within a defined space or envelope, e.g., within a garage. The sensor and indicator may also be located laterally with respect to the vehicle so that the distance between the vehicle side and the sensor can be determined whereby the vehicle can be located laterally within the defined space or envelope. The device remains active at all times, precluding any need for manual intervention to activate it, without compromising power consumption. A distance dependent means for dynamic desensitization of the receiver subsystem is provided so as to ignore reflection artifacts from irrelevant off-axis objects close to the sensor and to avoid false triggering due to ringing within the sensor. The distance dependence of the desensitization is implemented by using an exponentially decaying reference signal as a dynamic detection amplitude threshold for comparison against the amplitude of received echo signals for a predetermined period of time after exciting the sensor with a transmit pulse. Shortened transmit excitation burst times are also used when measuring at close ranges to reduce sensor ring time.
38 Citations
14 Claims
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1. A method of positioning a vehicle within a defined space comprising the steps of:
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providing an ultrasonic sensor fixed at a predetermined reference location; emitting ultrasonic energy signals within the defined space at periodic predetermined intervals and receiving echoes reflected by the vehicle while ignoring ultrasonic reflection artifacts from irrelevant off-axis objects close to the sensor; sensing the proximity of the vehicle relative to the sensor as the vehicle enters the defined space; and using the sensed proximity, indicating to a driver of the vehicle the proximity of the vehicle to the reference location thereby enabling the driver of the vehicle to position the vehicle within the defined space. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. In a system for aiding positioning of a vehicle, said system using transmitted and reflected acoustic or electrical energy to determine a distance between a sensor and an approaching vehicle, a method for mitigating false responses comprising:
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comparing signal amplitudes of echoes as received against a dynamically changing reference signal voltage which decreases exponentially over time to a predetermined threshold value; and
,ignoring said received echoes if the signal amplitude thereof is less than the reference signal voltage.
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Specification