JP2729730B

PURPOSE:To reduce the size of a magnetic sensor by detecting two components, in the vertical direction and in the horizontal direction, of a magnetic field generated by an alternating current flowing through a cable so as to calculate the cable position. CONSTITUTION:Three magnetic sensors 4x-4z are provided in the axial directions of xyz co-ordinates fixed to a robot in such a manner that the optimum sensitivity direction agrees with the x-axis in the case of the sensor 4x, y-axis in the case of the sensor 4y and z-axis directing downward in the vertical direction in the case of sensor 4z, respectively, and installed close to each other. A magnetic sensor container 4a for storing the sensors 4x-4z is suspended from a robot through a universal joint. In a signal processing means 9, the respective signals ix-iz and i1, i2 output from a filter block 9a are amplified by a signal amplifying block 9b, and then operated according to a designated expression by an arithmetic block 9c to calculate an angle theta in the horizontal direction and an angle phi in the vertical direction that show the attitude of a robot to a submarine cable, and geomagnetic orientation beta.