Automatic gain control circuit of multistage high dynamic range used in ultrasonic distance measurement

Abstract

The invention relates to an automatic gain control circuit of multistage high dynamic range used in an ultrasonic distance measurement, which comprises n stages of sequentially and serially connected amplifying circuits; the input terminal of a first stage is connected with an input signal; the nth output forms an output signal which goes through sequentially a serially connected sampling circuit, a PID circuit and an amplitude limiter circuit, and then is respectively connected with each technotron; and the signal input terminal of the PID circuit is also connected with a given circuit. Each stage of amplifying circuit comprises an operational amplifier, non-inverting input terminals and inverting input terminals of all the operational amplifiers are respectively connected with the drain electrode of one technotron, the source electrode of each technotron is grounded, the grid electrode of the technotron connected with the inverting input terminal of the operational amplifier is connected with the output terminal of the amplitude limiter circuit, and the grid electrode of the technotron connected with the non-inverting input terminal of the operational amplifier is grounded. The control circuit can lead the amplification times to be stabilized in a given value. Simultaneously, the dynamic range is improved by adopting multistage amplification, and the gain is controlled by adopting a voltage controlled resistor so as to lead the gain to be stepless adjustable.

Description

technical field [0001] The invention relates to an echo signal automatic control technology of an ultrasonic ranging system. In particular, it relates to a multi-stage high dynamic range automatic gain control circuit for ultrasonic distance measurement, which is suitable for distance measurement based on ultrasound in industrial sites, and can also be used for real-time obstacle avoidance of mobile robots or autonomous vehicle navigation. Background technique [0002] In the air medium, the sound wave is affected by reflection, scattering, absorption and other factors along its propagation path, and its intensity will rapidly attenuate with the increase of the propagation distance. Therefore, when the obstacle is far away from the ultrasonic transducer, the echo signal is very weak, and when the obstacle is close to the ultrasonic transducer, the echo signal amplitude is large. The fluctuation of the echo signal amplitude will affect the reception and subsequent processing ...

AI Technical Summary

Problems solved by technology

Since the ultrasonic signal is affected by many factors when propagating in the air, the automatic gain control circuit designed by traditional methods has certain limitations.

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