Vehicle system including sensor unit for detecting magnetic marker laid on a road

A sensor unit to be attached to a movable body to detect a magnetic marker, the sensor unit comprising:

• at least one magnetic sensor which measures magnetism acting from the magnetic marker;
• at least one non-contact displacement sensor which measures a displacement of the movable body relative to a surface where the magnetic marker is laid;
• and
• circuitry configured to
• acquire magnetic measurement values measured by the at least one magnetic sensor, and
• change a temporal interval for acquiring the magnetic measurement values in accordance with a displacement measurement value measured by the at least one non-contact displacement sensor.

A system to detect a magnetic marker, the system comprising:

• a movable body;
• and
• a sensor unit attached to the movable body, wherein
• the sensor unit includes
• at least one magnetic sensor which measures magnetism acting from the magnetic marker, and
• at least one non-contact displacement sensor which measures a displacement of the movable body relative to a surface where the magnetic marker is laid, wherein
• the at least one non-contact displacement sensor includes
• a light source which irradiates light onto the surface,
• an imager which captures images of the surface in synchronism with light emitting operation of the light source, and
• a circuit configured to calculate the displacement by identifying an amount of shift which results in a highest match between two temporally successive images when one of the two temporally successive images is positionally shifted by the amount of shift and compared with the other of the two temporally successive images.