Crawler vehicle with automatic probe normalization

A magnetic robotic crawler vehicle for traversing a surface, comprising:

• a chassis;
• a plurality of wheels mounted to the chassis and configured to traverse the surface during normal operation of the vehicle, the plurality of wheels including:
• two magnetic drive wheels, wherein the drive wheels are spaced apart in a lateral direction and rotate about a rotational axis and wherein the drive wheels are configured to be driven independently, thereby driving and steering the vehicle along the surface, and wherein a longitudinal axis of the vehicle extends perpendicularly to the lateral, rotational axis in a front and back direction and through the midpoint between the two drive wheels, and
• a stabilizing wheel, wherein the stabilizing wheel is spaced apart from the two magnetic drive wheels in the longitudinal direction and configured to roll along the surface;
• a sensor probe assembly supported by the chassis, wherein the sensor probe assembly comprises:
• a dry coupled wheel probe having a probe wheel rotating about a fixed probe transducer shaft, wherein the probe wheel is configured to passively roll generally in a direction of travel of the vehicle along the surface, and wherein a probe transducer within the probe transducer shaft is configured to measure characteristics of the surface at the prescribed angle, and wherein the sensor probe assembly is mounted to the chassis such that the probe transducer is positioned at the midpoint between the two drive wheels;
• and
• a probe normalization mechanism coupled to the sensor probe assembly, the probe normalization mechanism being configured to maintain at least the probe transducer of the sensor probe assembly at a prescribed angle relative to the surface during normal operation of the vehicle as a function of a curvature of the surface.