The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 02, 1987
Filed:
Nov. 20, 1985
John J Sallas, Plano, TX (US);
Toby R Trevino, Garland, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A vibrator seismic source has a sweep generator for providing a pilot signal and sensors for generating a feedback signal representative of the force imparted to the ground by the vibrator pad. Circuitry is incorporated for separating the fundamental signal from the feedback signal and for separating the distortion from the feedback signal. Means are provided for generating a control signal for controlling the action of the vibrator means. Included are means for reducing the amplitude of the pilot signal a designated amount, determined by the distortion, and means for algebraically summing the reduced amplitude pilot signal and the fundamental signal to provide an error signal. The error signal is input to a loop filter to perform real time correction of the control signal. The reduced amplitude pilot signal is input to means for adjusting the control signal for trends in the distortion. Additionally, the control system employs a phase detector circuit that outputs any phase difference between the feedback and pilot signals. The phase difference is applied to the control signal to shift the feedback signal phase to correspond to the pilot signal.