CN101975573A - Electromagnetic induction north seeker - Google Patents

Abstract

The invention relates to an electromagnetic induction north seeker comprising a coil (1), a winding post (2) and a driving motor (3), wherein the coil (1) is wound around the winding post (2), an axial direction of the winding post (2) is perpendicular to a rotary axial direction of the driving motor (3), induced electromotive force signals generated by the coil (1) are led out by a conducting wire (4), and both ends of the winding post (2) are connected with a magnetic detecting panel (5). The electromagnetic induction north seeker is characterized in that an included angle of the axial direction of the winding post (2) and the earth magnetic north can be determined by uniformly rotating the driving motor (3) and measuring induced electromotive force generated by the coil (1). The electromagnetic induction north seeker is a quick directional device which has simple structure and high accuracy.

Description

A kind of electromagnetic induction is sought northern instrument

Technical field

The present invention relates to a kind ofly, have specific use aspect directed and the navigation, but also can be widely used in the measurement of engineering and mechanical tilt variation based on the northern instrument of seeking of electromagnetic induction principle.

Background technology

Refer to that north and orientation are research topics that relates generally in engineering and the scientific research, as the aspects such as measurement of navigation and engineering and mechanical tilt variation.It is several that present traditional orientation method has compass, gyroscope type to seek northern instrument and GPS orientation method etc.Traditional compass is simple in structure, it is convenient to use, but precision is low, a little less than the antijamming capability; Gyroscope type is sought northern instrument precision height, but configuration complexity, cost height, seek north the time long; The GPS orientation method uses simple, but system is huge, dependence is stronger.Refer to that at present north and directed engineering, particularly military project slewing and navigation field press for high-precision rapid north-seeking instrument, so develop and new and effectively seek northern instrument and just become the technical matters that many correlation engineering field presses for solution.

The invention provides a kind of high-precision rapid north-seeking instrument, be a kind of north finding device based on electromagnetic induction principle.Electromagnetic induction is sought northern instrument by coil, wrapping post, and drive motor is formed, and coil is around in the wrapping post periphery, the axial rotary that is axially perpendicular to drive motor of wrapping post, and the two ends of wrapping post are connected with the magnetic detection panel.Seek northern instrument when electromagnetic induction and place the terrestrial magnetic field, and at the uniform velocity during rotary drive motor, according to Faraday's electromagnetic induction law, the coil two ends produce induction electromotive force.Under rotating conditions at the uniform velocity, the size of induction electromotive force and wrapping post axially are sine function with the angle of earth magnetic north and concern.When coil axes when parallel with earth magnetic north direction, the induction electromotive force that the coil two ends produce is zero, and the time dependent slope maximum of sine function at this moment, therefore by determining that induction electromotive force is zero position and the direction that can determine earth magnetic north.It is a kind of high precision slewing device simple in structure that a kind of electromagnetic induction provided by the invention is sought northern instrument.Because magnetic declination is the function of measurement point longitude and latitude, therefore combine with the GPS location technology, electromagnetic induction seek northern instrument can provide a kind of high precision seek fast geographic north to device.

Summary of the invention

Principle of the present invention is based on Faraday's electromagnetic induction law.As shown in Figure 1, electromagnetic induction is sought northern instrument and is made up ofcoil 1, wrappingpost 2,drive motor 3,coil 1 is around in wrappingpost 2 peripheries, the axial rotary that is axially perpendicular to drivemotor 3 of wrappingpost 2, the induced electromotive force signal thatcoil 1 produces is drawn bylead 4, and the two ends of wrappingpost 2 are connected with magnetic detection panel 5.The earth is a big magnet.The fundamental of terrestrial magnetic field F as shown in Figure 2, its vertical component is Z; Horizontal component is H; East and West direction and north-south component are respectively Y and X; Magnetic declination is D; Magnetic dip is I.

Seek northern instrument when electromagnetic induction and place the terrestrial magnetic field, and at the uniform velocity during rotary drive motor, according to Faraday's electromagnetic induction law, the coil two ends produce induction electromotive force.Under rotating conditions at the uniform velocity, the size of induction electromotive force and coil axes are the sine function relation to the angle with earth magnetic north.The principle of work that electromagnetic induction is sought northern instrument is consistent with the principle of generator.Compare the magnetic field that the terrestrial magnetic field produces corresponding to permanent magnet in the generator with generator.If the angular velocity of rotation ofdrive motor 3 is ω, the number of turn of coil is N, and the area ofmagnetic detection panel 5 is A, and magnetic induction density is B (B=μ H, μ are magnetic permeability).Induction electromotive force u thatcoil 1 two ends produce and the pass of time t are:

u＝NBA?sin(ωt+δ)＝k?sin(ωt+δ)，

δ is an initial phase in the formula, and k (k=NBA) is the amplitude of induction electromotive force.Giving under the condition of fixed angular speed, the amplitude k of induction electromotive force is proportional to turn number N, the area A ofmagnetic detection panel 5, magnetic induction density B.Therefore wrappingpost 2 andmagnetic detection panel 5 should be selected the high ferromagnetic material of magnetic permeability (Fe, Co, Ni metal and its alloy).Electromagnetic induction is sought the northern speed of seeking of northern instrument and is determined by the angular velocity omega of drive motor 3.The induction electromotive force value in some cycles of discrete sampling also can be determined the phase function f (t) in the following formula, that is:

f(t)＝ωt+δ。

Phase function f (t) represents the angle of the axial n of t wrapping post and earth magnetic H sometime, as shown in Figure 3.When phase function f (t) satisfies condition:

f(t)＝2jπ，

(j=0,1,2,3 ...) interval scale is parallel with earth magnetic north direction at the axial n of thisposition wrapping post 2, so north orientation that the present invention seeks is a magnetic north H direction.Earth magnetic north direction and geographic north between angle be called magnetic declination.Magnetic declination D is the function of measurement point longitude and latitude in the geomagnetic field elements shown in Figure 2.The longitude and latitude of measurement point can be determined by the GPS technology.Therefore combine with the GPS location technology, electromagnetic induction seek northern instrument provide a kind of high precision seek fast geographic north to device.

Description of drawings

Below in conjunction with accompanying drawing the present invention is described in further detail:

Fig. 1 seeks the structural representation of northern instrument for electromagnetic induction;

Fig. 2 is the fundamental synoptic diagram of terrestrial magnetic field;

Fig. 3 is that the angle of the axial n of wrapping post and magnetic field of the earth H concerns synoptic diagram under the condition of constant angular velocity of rotation;

Fig. 4 is the position in A-A reference direction,hole 6 and the axial synoptic diagram that concerns at initial time of wrappingpost 2;

Fig. 5 seeks the northern instrument and the synoptic diagram that concerns around Z-spindle motor driven in rotation for the induction of X-axle and Y-direction of principal axis two-dimensional electromagnetic;

Fig. 6 respond to for two-dimensional electromagnetic under the constant angular velocity of rotation condition of 100 (degree/seconds) that the signal seek northern instrument is exported and with the relation of magnetic north.

Specific embodiment

Electromagnetic induction is sought northern instrument and is made up ofcoil 1, wrappingpost 2,drive motor 3,coil 1 is around in wrappingpost 2 peripheries, the axial rotary that is axially perpendicular to drivemotor 3 of wrappingpost 2, the induced electromotive force signal thatcoil 1 produces is drawn bylead 4, and the two ends of wrappingpost 2 are connected with magnetic detection panel 5.Wrappingpost 2 andmagnetic detection panel 5 select for use ferromagnetic material to make.Drive motor 3 is permanent magnet DC motor or stepper motor.Two coil winding are individually fixed in orthogonal both direction and seek northern instrument perpendicular to the axial rotary formation two-dimensional electromagnetic induction of drive motor.Because the function of seeking northern instrument is determined the angle of a certain reference direction and north orientation often, therefore must at first determine the initial angle of axial and this reference direction of wrapping post 2.As shown in Figure 4, establishing reference direction is the A-A direction.The position ininitial position hole 6 is located on thedrive motor 3 and is in the axial of wrapping post 2.Whenmotor 3 at the uniform velocity rotated, the reference position oflocation hole 6 was by photoelectric device or hall device control.When wrappingpost 2 be axially perpendicular to the A-A direction time, the logical light oflocation hole 6 are accepted light intensity signal by photosensitive components and parts, and get and be time zero this moment.Ifmotor 3 at the uniform velocity rotates with angular velocity omega, the axial n of wrappingpost 2 is parallel with earth magnetic north direction when the time is t, and at this moment the angle of A-A direction and magnetic north direction is pi/2-ω t, with geographic north to angle be pi/2-ω t+D.

Two coil winding are individually fixed in orthogonal both direction and seek northern instrument perpendicular to the axial rotary formation two-dimensional electromagnetic induction of drive motor.If two coil winding are individually fixed in orthogonal X-axle and Y-direction of principal axis, motor is around the rotation of Z-axle, and as shown in Figure 5, then phase differential is a pi/2 between the sine function of the electromotive force of X-axle and Y-direction of principal axis coil winding.Adopt two-dimensional electromagnetic induction gyroscope,, and rotate with constant speed, then when output signal value is zero after the deduction zero-bit, represent the axially parallel of this winding with the terrestrial magnetic field around the Z-axle if two-dimensional electromagnetic is responded to gyroscope by motor-driven.Fig. 6 is for being under the condition of 100 (degree/seconds) at angular velocity, the signal of electromagnetic induction gyroscope X-axle and Y-axle export and with the relation of terrestrial magnetic field direction.When a certain winding output valve was zero, the output amplitude of another vertical with it winding was maximum.Electromagnetic induction is sought the northern speed of seeking of northern instrument and is determined by the angular velocity omega of drive motor 3.The induction electromotive force value in some cycles of discrete sampling and can determine phase function f (t), further determine thus winding axially and the angle of terrestrial magnetic field, so electromagnetic induction to seek northern instrument be a kind of high precision slewing device simple in structure.

Claims (5)

1. an electromagnetic induction is sought northern instrument, it is characterized in that: seek northern instrument by coil (1), wrapping post (2), drive motor (3) is formed, coil (1) is around in wrapping post (2) periphery, the axial rotary that is axially perpendicular to drive motor (3) of wrapping post (2), the induced electromotive force signal that coil (1) produces is drawn by lead (4), and the two ends of wrapping post (2) are connected with magnetic detection panel (5).

2. a kind of electromagnetic induction as claimed in claim 1 is sought northern instrument, it is characterized in that: two coil winding (2) are individually fixed in orthogonal both direction and seek northern instrument perpendicular to the axial rotary formation two-dimensional electromagnetic induction of drive motor (3).

3. a kind of electromagnetic induction as claimed in claim 1 is sought northern instrument, it is characterized in that: wrapping post (2) and magnetic detection panel (5) select for use ferromagnetic material to make.

4. a kind of electromagnetic induction as claimed in claim 1 is sought northern instrument, it is characterized in that: the reference position in the initial position hole (6) of being opened on drive motor (3) is by photoelectric device or hall device control.

5. a kind of electromagnetic induction as claimed in claim 1 is sought northern instrument, it is characterized in that: drive motor (3) is permanent magnet DC motor or stepper motor.

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