High Intensity and Uniform Magnetic Field Sensor for Trenchless Underground Cable Detection

To solve the problems of insufficient magnetic field density and uneven magnetic field distribution when trenchless detection of underground cables is performed. This paper designs a high intensity and uniform magnetic field sensor for trenchless underground cable detection, which involves high-precision excitation schemes and interference-resistant sensor physical structures. The excitation scheme is a low-frequency triangular wave, and the physical structure of the sensor is a round coil sensor. This paper compares the magnetic field excitation capabilities of round, rectangular, and diamond-shaped coils. Simulation results show that the round coil produce stronger magnetic field strength at the same location. To quantify the uniformity of the magnetic field, this paper proposes three evaluation metrics for different spatial locations. To solve the problem of non-uniform magnetic field strength, this paper tests five different excitation signals for each of the three coils. The experimental results show that the round coil with low-frequency triangular wave excitation produces a high magnetic field strength and better uniformity.