Error correction device

An error correction device (34) is provided in a work vehicle and corrects an error based on a measured value of a sensor device provided with a GNSS sensor and a gyroscope sensor, the error correction device comprising: a first acquisition unit (341) that acquires a first signal from the GNSS sensor and a second signal from the gyroscope sensor; a velocity vector acquisition unit that acquires a velocity vector of the work vehicle in an own coordinate system measured by the GNSS sensor and an angular velocity in a sensor coordinate system measured by the gyro sensor, the sensor coordinate system having three axes based on the sensor device; a second acquisition unit (343) that acquires the steering amount of the work vehicle; a set position specifying unit (344) that specifies a set position on the basis of the acquired steering amount, the set position being set at a position different from that of the sensor device in the sensor coordinate system; and a velocity vector correction unit (347) that calculates