SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a position indicating system aims at eliminating the measurement accuracy error that the incomplete level of optic fibre top placed the production, improves the degree of accuracy that the position was instructed.
To achieve the above object, the present invention provides an azimuth indicating system, including:
the device comprises a fiber optic gyroscope, an electronic inclinometer and an upper computer;
the optical fiber gyroscope and the electronic inclinometer are connected with the upper computer.
Optionally, the fiber optic gyroscope includes:
the optical fiber gyroscope comprises an inertial sensitive component and an information processing circuit;
the fiber optic gyroscope inertia sensitive component is connected with the input end of the information processing circuit, and the output end of the information processing circuit is connected with the upper computer.
Optionally, the system further comprises:
an electronic compass;
the electronic compass is connected with the upper computer.
Optionally, the electronic compass is a three-axis strapdown magnetic resistance type digital magnetic compass.
Optionally, the system further comprises:
a turntable;
the turntable is connected with an upper computer, the fiber-optic gyroscope is fixed on the table surface of the turntable, and the sensitive shaft of the fiber-optic gyroscope is vertical to the rotating shaft of the turntable.
Optionally, the turntable is driven by a stepping motor, and an encoder of the stepping motor is connected with the upper computer.
Optionally, the system further comprises:
a power converter;
the input end of the power converter is used for connecting an external power supply, and the output end of the power converter is respectively connected with the fiber-optic gyroscope and the electronic inclinometer.
Optionally, the fiber optic gyroscope is a single sensitive axis fiber optic gyroscope.
Compared with the prior art, the utility model the beneficial effect who exists is:
the utility model discloses an add the electron inclinometer in position indicating system, measure the horizontal inclination deviation between optic fibre top's sensitive axle place plane and the horizontal plane to send optic fibre top's measured value and horizontal inclination deviation for the host computer, the host computer can be when calculating the true north direction according to optic fibre top's measured value, revise the calculated result through the horizontal inclination deviation, obtain the accurate position of true north direction. The utility model discloses can effectively improve the degree of accuracy of position indication.
Detailed Description
In order to make the technical problem, technical solution and advantageous effects to be solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to illustrate the present invention in further detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Referring to fig. 1, it shows a schematic structural diagram of an orientation indicating system provided by an embodiment of the present invention, and the orientation indicating system includes: the device comprises an optical fiber gyroscope, an electronic inclinometer and an upper computer, wherein the optical fiber gyroscope and the electronic inclinometer are connected with the upper computer.
In the embodiment of the present invention, referring to fig. 2, the north-seeking principle of the azimuth indicating system is:
the fiber-optic gyroscope can be placed on a rotating mechanism such as a turntable and the like, the rotating mechanism drives the fiber-optic gyroscope to rotate, and a sensitive shaft (a sensitive shaft plane is formed when the sensitive shaft rotates) of the fiber-optic gyroscope is vertical to a rotating shaft of the rotating mechanism. In the ideal measuring situation, the rotating mechanismThe rotating shaft is vertical to the horizontal plane so as to ensure that the plane of the sensitive axis of the fiber-optic gyroscope is parallel to the horizontal plane. When the sensitive axis of the fiber-optic gyroscope points to a certain direction on the plane of the sensitive axis, the fiber-optic gyroscope can measure the horizontal component omega of the earth angular rate in the direction
e1The measurement is a sinusoidal signal, where the zero values correspond to the true east and the true west, the peaks correspond to the true south and north, ω
eThe rotation speed of the earth is used as the rotation speed of the earth,
the latitude of the earth. Under the condition of not considering the error of the device, if the included angle between the sensitive axis of the fiber-optic gyroscope and the due north direction is theta, the output measured value of the fiber-optic gyroscope is as follows:
further, derived to
And determining the north orientation according to the included angle theta between the sensitive axis of the fiber-optic gyroscope and the north orientation.
However, since the fiber optic gyroscope generally has a null offset, a calibration factor offset, and a random error, the actual output value of the fiber optic gyroscope is:
wherein the random error epsilon0Suppression can be achieved by filtering and lengthening the sampling time, but ultimately depends on gyro accuracy, but is limited by a scaling factor KεThe error caused by the temperature is small and can be ensured by the precision of a control device, so that the zero offset omega of the fiber-optic gyroscope caused by the temperature0The greatest impact on accuracy. In order to eliminate the influence of temperature drift, the direction indicating system of the utility model can search north through a two-position methodThe following are:
(1) the sensitive axis of the fiber-optic gyroscope points to any direction in the plane of the sensitive axis, the included angle between the direction and the due north direction is set as theta, and the output measured value of the fiber-optic gyroscope at the moment is
(2) The sensitive shaft of the fiber-optic gyroscope is rotated by 180 degrees, and the output measured value of the fiber-optic gyroscope at the moment is as follows:
(3) subtracting the measurements in the two directions yields:
it can be seen that in the third step, the zero offset ω is directly eliminated by subtracting the measured values of the fiber-optic gyroscopes in the two directions0The influence of (c).
Further, considering that the fiber optic gyroscope is not completely horizontally placed in actual measurement, assuming that the horizontal tilt angle deviation between the plane of the sensitive axis of the fiber optic gyroscope and the horizontal plane is α, the measurement value output by the fiber optic gyroscope can be further described as:
similarly, in the north-seeking method of two positions, the following can be derived:
according to the formula, the upper computer can accurately calculate the true north direction only by obtaining the measured values of the fiber-optic gyroscope in two directions (the difference between the two directions is 180 degrees), the measured value of the electronic inclinometer and the local latitude. The local latitude can be input to the upper computer by external personnel.
It can be seen that, the utility model discloses an add the electron inclinometer in position indicating system, measure the horizontal inclination deviation between optic fibre gyroscope's sensitive axis plane and the horizontal plane, and then send optic fibre gyroscope's measuring value and horizontal inclination deviation for the host computer, the host computer can be when calculating the true north direction according to optic fibre gyroscope's measuring value, revises the calculated result through the horizontal inclination deviation, obtains the accurate position of true north direction. The utility model discloses can effectively improve the degree of accuracy of position indication.
Optionally, as a possible implementation manner, referring to fig. 3, the fiber optic gyroscope includes:
the device comprises a fiber optic gyroscope inertia sensitive component and an information processing circuit.
The fiber optic gyroscope inertia sensitive component is connected with the input end of the information processing circuit, and the output end of the information processing circuit is connected with the upper computer.
The embodiment of the utility model provides an in, the measurement of earth rotation speed is realized to optic fibre top inertia sensing part, and information processing unit accomplishes the rich collection of optic fibre top data and signal processing, output measured value.
Optionally, as a possible implementation manner, referring to fig. 3, the system further includes:
an electronic compass.
The electronic compass is connected with the upper computer.
Optionally, as a possible implementation manner, the electronic compass is a three-axis strapdown magnetic resistance type digital magnetic compass.
The embodiment of the utility model provides an in, consider that the angular velocity of rotation of earth is minimum at the horizontal component of east and west direction, so the optic fibre top should let its sensitive axle point to just east direction or just west direction as far as possible when measuring, can improve measurement accuracy. Therefore, the embodiment of the utility model provides an electronic compass has been added in the position indicating system to roughly measure the east-west direction. The electronic compass can be a three-axis strapdown magnetic resistance type digital magnetic compass, and a hard magnetic and soft magnetic calibration algorithm is adopted, and a course angle is calculated in real time through a CPU (central processing unit), so that the electronic compass can achieve higher precision in an environment with magnetic field interference.
Optionally, as a possible implementation manner, referring to fig. 2, the system further includes:
a turntable.
The turntable is connected with an upper computer, the fiber-optic gyroscope is fixed on the table surface of the turntable, and the sensitive shaft of the fiber-optic gyroscope is vertical to the rotating shaft of the turntable.
Optionally, as a possible implementation manner, the turntable is a turntable driven by a stepping motor, and an encoder of the stepping motor is connected with the upper computer.
The embodiment of the utility model provides an in, through step motor driven revolving stage, can realize the directional accurate control of optic fibre top sensitive axle. For example, the sensitive shaft of the fiber optic gyroscope is precisely indexed by 180 degrees.
Optionally, as a possible implementation manner, referring to fig. 3, the system further includes:
a power converter.
The input end of the power converter is used for connecting an external power supply, and the output end of the power converter is respectively connected with the fiber-optic gyroscope and the electronic inclinometer.
In the embodiment of the present invention, the power converter converts the externally provided 28V dc power into ± 5V dc power to satisfy the power consumption requirements of the fiber optic gyroscope and the electronic inclinometer. In addition, when the system further comprises an electronic compass or a turntable, the power converter can also supply power to the electronic compass or the turntable.
Optionally, as a possible implementation manner, the fiber optic gyroscope is a single sensitive axis fiber optic gyroscope.
The embodiment of the utility model provides an in, adopt single sensitive axle fiber-optic gyroscope can reduce system cost.
In addition, the fiber-optic gyroscope, the electronic inclinometer, the electronic compass and the like can realize data transmission with an upper computer through an RS422 serial communication interface shown in FIG. 3.
Based on the above, the embodiment of the present invention provides a north-seeking process of an azimuth indicating system:
(1) the measuring personnel writes the local latitude value into an upper computer;
(2) adjusting the level of the fiber optic gyroscope, ensuring that the deviation of the horizontal inclination angle is less than 1 degree, and simultaneously sending a measurement result to an upper computer by the electronic inclinometer;
(3) roughly measuring by using an electronic compass for about 10S, estimating to obtain the east-righting direction, and sending the azimuth angle of the east-righting direction to an upper computer;
(4) the upper computer controls a sensitive axis of the fiber-optic gyroscope to point to the east-righting direction through the turntable, starts to statically collect data for 120s, and sends the data to the upper computer through the communication interface after the data collection is finished;
(5) the upper computer controls the sensitive shaft of the fiber-optic gyroscope to accurately rotate 180 degrees through the turntable, statically collects data for 120s, and sends the data to the upper computer through the communication interface after the data collection is finished;
(6) and the upper computer accurately determines the north direction according to the measurement data.
The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.