PROXIMITY SENSING SYSTEMS AND METHODS

摘要

Methods, systems and device are provided for improving the range and accuracy of proximity measurement such as in ultrasonic sensing systems. In particular, the blind zone caused by reverberation signals can be reduced or eliminated by attenuating signals received during the time period corresponding to the blind zone without. In an implementation, an attenuator circuit is selected by a switch to process received signals during the blind zone time period and deselected by the switch after the time zone time period. Additionally, the accuracy and range of the measurement can be improved by varying the gain provided to the received signals based on the varying measuring distance. In an implementation, a gain-adjustable amplifier is controlled by a gain control signal to provide incremental gain as time increases.

主权项

1. An ultrasonic sensing system, comprising:
an ultrasonic transmitter configured to provide a transmission of ultrasonic signals; an ultrasonic receiver configured to receive ultrasonic signals generated as a result of the transmission including reverberation signals and echo signals; an attenuator circuit connectable to the ultrasonic receiver via a switch, the attenuator circuit operable for attenuating the received ultrasonic signals; and a microcontroller unit (MCU) configured to control the switch to electrically couple the ultrasonic receiver with the attenuator circuit during a predetermined period of time after the transmission of ultrasonic signals and electrically decouple the ultrasonic receiver from the attenuator circuit prior to and after the predetermined period of time.