| 摘要 |
PURPOSE:To detect the travelling direction of a travelling object with higher accuracy without giving any compensation to the magnetic field with use of a compensating magnet, by magnetically shielding the residual magnetism of a magnetic substance and at the same time using a magnetic permeable material that has no magnetic saturation with the earth magnetism. CONSTITUTION:A magnetic permeable material like a silicon steel, etc. 3 that has higher permeability than a roof steel plate 4 of a car 2 functioning as the first magnetic material and has no magnetic saturation with the earth magnetism is covered at the inner side of the plate 4. an azimuth detecting sensor 1 is attached to the inside of the permeable material with a distance L secured between them. The signals detected by the sensor 1 are sent to a signal processing circuit 5 set at the inside of the car to detect the azimuth. In such way, the effect of the residual magnetism of the magnetic material is greatly reduced to the magnetism detection of the sensor 1. Furthermore the hysteresis can be reduced in the rotating direction compared with a magnetic permeable material having high permeability and the magnetic saturation. Thus the travelling direction can be detected accurately for a travelling object without giving any compensation to the magnetic field. |
