JPH0769415B2 - Direction / speed measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention uses GPS radio waves to measure the bow (nose) direction of a moving body such as a ship or an airplane, and moves in the bow (nose) direction. The present invention relates to a device for measuring speed and moving speed in a direction perpendicular to the speed.

(Prior Art) Conventionally, a gyro compass or a magnetic compass was used as a device for measuring a ship (nose) head. Since it was pointed out, it was unusable in the polar regions.

Also, as the speed measuring device, there were a Doppler log, a Doppler radar, etc., but all of them were expensive because they required a transmitter.

Furthermore, there was no device that gave both direction and speed at the same time.

(Problems to be solved by the invention) It is not effective in polar regions to use a means for detecting the rotation of the earth and the horizontal component of the earth's magnetic field to measure the direction of a moving object.
Moreover, an expensive transmitter was required for speed measurement. There was a demand for simultaneous measurement of direction and speed with high accuracy, and for an inexpensive measuring device.

(Means for Solving Problems) In the present invention, two GPS receivers receive radio waves emitted from GPS satellites to measure the heading of the bow and the moving speed in the bow direction. , A device for measuring the lateral movement speed on the bow side and the lateral movement speed on the stern side, the purpose of which is to provide the bow (nose) direction and speed at the same time without the need for an expensive transmitter, and even in polar regions. It is to realize a highly reliable and inexpensive azimuth and velocity measuring device that does not fall into the impossible of measurement. This will be described below with reference to the drawings.

(Embodiment) FIG. 1 is a block diagram of an embodiment of the present invention, in which 1 is the first
Antenna, 2 is a first GPS receiver, 3 is a calculator, 4 is a second antenna, 5 is a second GPS receiver, and 6 is a display. Here, the first antenna 1 is near the bow on the line connecting the bow and stern,
The second antennas 4 are installed near the stern, respectively.

This operation will be described next. The signals of at least four GPS satellites received by the first antenna 1 are sent to the first GPS receiver 2, and the movement speed V ₁ and movement of the first antenna 1 Measure the azimuth α. Since it is well known that many existing GPS receivers can measure the moving speed and direction of the antenna, the description is omitted here. The first GPS receiver 2 sends the measured moving speed V ₁ and moving direction α to the first input terminal of the calculator 3. At the same time, the signals of at least four GPS satellites received by the second antenna 4 are sent to the second GPS receiver 5,
The moving speed V ₄ and moving direction β of the second antenna 4 are measured. The second GPS receiver 5 sends the measured moving speed V ₄ and moving direction β to the second input terminal of the calculator 3.
The computing unit 3 calculates the moving speed V ₁ and movement direction α of the _first antenna 1 transmitted to the first input terminal and the moving speed V ₄ and movement of the second antenna 4 transmitted to the second input terminal. From heading β and heading direction θ, heading direction moving speed V _1H = V _4H , bow side lateral moving speed V _1T , stern side lateral moving speed V _4T are calculated and displayed on display 6 as numerical value or vector To do.

The calculation contents of the calculator 3 will be described with reference to FIG. From Fig. 2, V _1H and V _4H are the speeds at which the hull moves _forward ( _backward ), so V _1H = V _4H . Therefore, V ₁ cos
Since (θ−α) = V ₄ cos (θ−β) and V ₁ , α, V ₄ and β are all known, the computing unit 3 can calculate the heading θ by solving this equation. You can This θ is V _1H = V ₁ c
By substituting for os (θ−α), the moving speed in the bow direction V _1H
Is calculated. Furthermore, V _1T = V ₁ sin (θ−α), V _4T = V ₄ sin
By substituting the above θ into (θ−β), the lateral movement speed V _1T on the bow side and the lateral movement speed V _4T on the stern side can be calculated.

As described above, according to the present invention, the first and second GPs are
By performing the above-mentioned processing by the computing unit using the S receiver, the heading and speed can be calculated and displayed simultaneously without the need for a transmitter as in the past. In addition, since the earth's rotation and geomagnetism are not used, accurate measurements are possible even in polar regions.

Moreover, since it has a simple structure, there is an advantage that an inexpensive, compact, and highly reliable device can be realized. So ships, cars,
It is possible to easily measure the moving direction and speed of an aircraft or the like, and it is extremely effective especially in polar regions.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a vector diagram showing the moving direction and speed of a ship. 1,4 …… First and second antennas, 2,5 …… GPS receiver, 3 …… Computer, 6 …… Display.

Claims (1)

[Claims] 1. A first and a second GPS antenna installed on the bow and the stern near the stern respectively, and the first and second G antennas.
First, to measure the moving speed and moving direction of the first and second antennas from the GPS satellite signals received from the PS antenna
And a second GPS receiver, and moving speeds and moving directions of the first and second antennas respectively sent from the first and second GPS receivers to a heading, a moving speed in a bow direction, An azimuth / speed measuring device comprising a computing unit for calculating the lateral movement speed on the bow side and the lateral movement speed on the stern side, and a display unit for displaying such information.