| 摘要 |
PURPOSE:To detect the derailment of an unmanned carrier and the foreign matters attached on a drive mark band by comparing the output signal levels of sensors with the upper and lower levels set previously to detect said signal level exceeding the prescribed range. CONSTITUTION:The output signals of sensors 3' and 3'' are inputted to the comparators 10 and 11 respectively. The output signal of the sensor 3' is compared with the lower limit level via a comparator 4' and with the upper limit level via a comparator 5'. While the output signal of the sensor 3'' undergoes the same comparison as the sensor 3' via a comparators 4'' and 5'' respectively. In this case the upper and lower limit levels are set previously. Among the output signals of the comparators 4', 4'', 5' and 5'', the results of comparison with the lower limit level are inputted to an AND gate 7. While the results of comparison with the upper limit level are inputted to a 1st OR gate 8. The output signals of both gates 7 and 8 are inputted to a 2nd OR gate 9. The output signal of the gate 9 serves as an abnormality detecting signal. Thus the presence of the foreign matters are detected via the comparison with the upper limit level. Then the derailment of an unmanned carrier is detected via the comparison with the lower limit level respectively. |
