Application Cases

Experiment Name: Hardware Implementation of Pipeline Positioning System

Experiment Description:
A feasibility study on a PCM-based pipeline positioning system was conducted: A function generator was used to produce multi-frequency currents at 4 Hz, 8 Hz, and 72 Hz, and the signals were output to the Aigtek ATA-308B power amplifier. After adjusting the RMS value of the output current to 1 A, the current was transmitted through shielded cables to a pipeline model to simulate real-world pipeline inspection conditions. After setting up the experimental platform, the magnetometer probe was kept perpendicular to the ground around the pipeline. The horizontal distance, vertical distance, and horizontal angle between the magnetometer probe and the pipeline model were adjusted and measured using a tape measure. Subsequently, the relationship between the measurement results at different positions and the actual conditions was recorded.

Research Direction: Nondestructive Testing of Pipelines

Test Equipment:
ATA-308 power amplifier, function signal generator, digital multimeter, oscilloscope, etc.

Experimental Procedure:
During the experiment, the probe remained perpendicular to the ground, while the horizontal distance, vertical distance, and horizontal angle between the probe and the pipeline were varied. The probe detected the magnetic field signals emitted by the pipeline. The signals were filtered and amplified by the signal processing circuit and then transmitted to the STM32F429 embedded processor to calculate the precise three-dimensional position.

The processed pipeline positioning results were displayed on an LCD. The angle, vertical distance, and horizontal distance of the magnetometer probe relative to the pipeline model were dynamically adjusted, and the readings on the LCD screen were recorded.

Experimental Results:
After testing, the average errors and linearity indicators for the horizontal angle, vertical distance, and horizontal distance measurements were satisfactory. The R² values for horizontal and vertical distance measurements were greater than 0.99, and the R² value for horizontal angle measurement was also greater than 0.99. In terms of measurement errors, the average error for horizontal angle was 2.51°, the average error for horizontal distance was 2.19 cm, and the average error for vertical height was 2.01 cm. These experiments validated the feasibility of the pipeline positioning system from an experimental perspective, laying the groundwork for subsequent testing in real-world environments.

Recommended Power Amplifier: ATA-308C

Figure: Specifications of the ATA-308C Power Amplifier