| 摘要 |
PURPOSE:To detect an own vessel speed of a vessel by use of an underwater detecting device, by shifting one of ultrasonic receiving information which is stored alternately, detecting coincidence with the other, and deciding the vessel speed in accordance with the maximum number of times of coincidence. CONSTITUTION:Digital distance information against an underwater object on the course of its own vessel, based on ultrasonic reception is stored in shift registers 14A, 14B alternately through a buffer memory 9 and is read out simultaneously. One of this register 14A or 14B is shift-controlled by a shift pulse from a shift pulse generator 29 controlled by a CPU3. Subsequently, outputs from the registers 14A, 14B are AND-processed by an AND gate 26, coincidence is detected, the number of times of coincidence is counted by a counter 28, and from a control output, etc. to the circuit 29 corresponding to displacement corresponding to a vessel speed in case when the number of times of coincidence is maximum, the CPU3 operates and calculates a vessel speed. Accordingly, a vessel speed of its own vessel can be detected by jointly using an underwater detecting device without using a device of a complicated constitution. |
