CN102662401A - Electromagnetic sensing tracking based navigation system - Google Patents

Abstract

The invention relates to an electromagnetic sensing tracking based navigation system which is mounted on an automatic navigation vehicle and comprises a sensor unit, a microprocessor, a servo steering engine, a steering engine and an external support. The servo steering engine is arranged on the automatic navigation vehicle and is connected with the sensor unit through the external support. The microprocessor is respectively connected with the servo steering engine and the sensor unit, and the steering engine is connected with the server steering engine. The sensor unit senses the current environment information of the automatic navigation cart and transmits the same to the microprocessor. The microprocessor transmits controls signals to the servo steering engine according to the acquired environment information. The servo steering engine controls the external support to steer so that the sensor unit can be always at the reference position. The steering engine controls steering of front wheels according to angle of the servo steering engine and navigation is completed. Compared with the prior art, the electromagnetic sensing tracking based navigation system has the advantages that running efficiency of an AGV (automatic guided vehicle) on the complicated path can be improved, and the like.

Description

A kind of navigational system based on the electromagnetic induction tracking

Technical field

The present invention relates to a kind of navigational system of automatic navigation vehicle, especially relate to a kind of navigational system based on the electromagnetic induction tracking.

Background technology

Automatic navigation vehicle (Automated Guided Vehicles; AGV) be called automatic guided vehicle again; Coming across the 1950's the earliest, is a kind of unpiloted intelligent haulage equipment of robotization, belongs to mobile robot system; Can go along predefined path, be the visual plant of modernized industrial automatic material flow system.Moreover, in military affairs and hazardous area, serve as that other detections and dismounting equipment are inherited in the basis with the automatic driving of AGV, can be used for the battlefield removal of mines, position investigation and hazardous environment operation.

AGV mainly contains oriented module, walking module, and orientation sensor, microprocessor, communication device, shifting apparatus and accumulator are formed.Wherein, orientation sensor is the key modules of perception path among the AGV, control walking path, and its sensitivity and dirigibility have determined the work efficiency of AGV dolly to a great extent.At present, guiding sensing mode commonly used is generally laser navigation mode, ultrasound wave navigation mode, vision guided navigation mode (being the CCD sensing mode) and electromagnetic induction navigate mode.

Electromagnetic induction tracking mode is applied to a lot of occasions owing to its high precision, high stability and the influence that is not subject to surrounding environment object and light.Under traditional electromagnetism tracking mode, sensor is fixed on the AGV dolly vehicle body, and its navigation can only lack dirigibility in strict accordance with fixing reference path walking; At pahtfinder hard is under many bends tracking situation, and the trolley travelling path is that reference path is long, and the speed of travel is slow.

Summary of the invention

The object of the invention is exactly the navigational system based on the electromagnetic induction tracking that the operational efficiency of a kind of AGV of raising under pahtfinder hard is provided for the defective that overcomes above-mentioned prior art existence.

The object of the invention can be realized through following technical scheme:

A kind of navigational system based on the electromagnetic induction tracking; This system is installed on the automatic navigation vehicle; Described navigational system comprises sensor groups, microprocessor, servo steering wheel, steering engine and outside support, and described servo steering wheel is located on the automatic navigation vehicle, and described servo steering wheel is connected with sensor groups through outside support; Described microprocessor is connected with servo steering wheel and sensor groups respectively, and described steering engine is connected with servo steering wheel;

The current environmental information of sensor groups induction automatic navigation vehicle; And this environmental information transferred to microprocessor; Microprocessor transmits control signal to servo steering wheel according to the environmental information that obtains; Servo steering wheel control support turns to and makes sensor groups be in the reference position always, and steering engine is according to the motion of servo steering wheel corner control automatic navigation vehicle.

Described sensor groups is formed by connecting through internal stent sensors A, sensor B, sensor C, sensor D and sensor E; Described sensor B, sensors A and sensor C are connected in turn on the internal stent equidistantly; Described sensor D is connected with sensor B; Described sensor E is connected with sensor C, and described sensor D, sensor E are symmetrical set, and all becomes the angle theta setting with the vertical line of sensors A, sensor B, sensor C place straight line.

Described θ satisfies 0 °＜θ≤20 °.

Described sensors A, sensor B, sensor C, sensor D and sensor E include telefault.

Compared with prior art; The present invention proposes a kind of new navigational system based on the electromagnetic induction tracking through adopting special sensor installation method; Through the sensor groups formed by five sensors device as signals collecting; And sensor D becomes angle to be not more than 20 ° with E with the vertical line of sensors A, B, C place straight line, and such setting can be with the accurate compensating potential difference of the difference in signal strength sampled value E of sensor D and E _Ab, particularly when bend, improved the operational efficiency of AGV more.

Description of drawings

Fig. 1 is installed on the structural representation on the AGV for navigational system of the present invention;

Fig. 2 is the relative position synoptic diagram of five sensors of sensor groups of the present invention;

Fig. 3 is electric potential difference E _dFuntcional relationship with position x;

Fig. 4 is the relation of bend situation sensor groups axis and guide line;

Fig. 5 is servo steering wheel corner and AGV front wheel angle corresponding relation.

Embodiment

Below in conjunction with accompanying drawing and specific embodiment the present invention is elaborated.

Embodiment

Like Fig. 1-shown in Figure 2; A kind of navigational system based on the electromagnetic induction tracking, this system is installed on the automatic navigation vehicle AGV, and described navigational system comprises sensor groups, microprocessor, servo steering wheel S0, steering engine and outside support; Described servo steering wheel is located on the automatic navigation vehicle; Described servo steering wheel is connected with sensor groups through outside support, and described microprocessor is connected with servo steering wheel and sensor groups respectively, and described steering engine is connected with servo steering wheel.The principle of work of above-mentioned navigational system is: the current environmental information of sensor groups induction automatic navigation vehicle; And this environmental information transferred to microprocessor; Microprocessor transmits control signal to servo steering wheel according to the environmental information that obtains; Servo steering wheel control support turns to and makes sensor groups be in the reference position always, and steering engine is according to the motion of servo steering wheel corner control automatic navigation vehicle.

Like Fig. 1-shown in Figure 2; Described sensor groups is formed by connecting through support sensors A, sensor B, sensor C, sensor D and sensor E; Described sensor B, sensors A and sensor C are connected in turn on the same support equidistantly; Described sensor D is connected with sensor B; Described sensor E is connected with sensor C, and described sensor D, sensor E are symmetrical set, and satisfies 0 °＜θ≤20 ° with the vertical line angle θ of sensors A, sensor B, sensor C place straight line.Five sensors of described sensor groups constitute by telefault.Five sensors are fixed through support, and be installed on the servo steering wheel S0.The distance that sensor groups is stretched out vehicle body is d, and height overhead is h, and the distance between sensors A and sensor B and sensor C is L/2.

According to electromagnetic induction principle, establish sensor distance guide wire distance and be x, then the sampled value E of AB sensor signal intensity difference _AbFor:

$E_{\mathrm{ab}}=k_{\mathrm{ab}}(\frac{h}{{\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="HDA00001684575700012.png"\; state="\{\{state\}\}">h</figure-callout>}}^2+{(x-L/2)}^2}-\frac{\mathrm{<figure-callout\; id="2"\; label="h\; h"\; filenames="HDA00001684575700012.png"\; state="\{\{state\}\}">h</figure-callout>}}{h^{}})---\left(1\right)$

In the formula, k _AbBe constant.If h=10, L=20, k _Ab=10, then the relation of sampled value and x is as shown in Figure 3.Can find out by curve shown in Figure 3, between (10,10) lane place, sampled value E _AbX is approximately proportionate relationship with the position, and establishing its coefficient is K, and K can be obtained in system's sampled value constantly that powers on by the sensors A of centre.During actual motion, obtain E through systematic sampling _Ab, this moment, x can pass through formula so

x＝E _ab/K (2)

Obtain.When trolley travelling was near bend, the angle of establishing between the normal of sensors A, B and C coil axis and lead was α, according to magnetic flux principle this moment

E _ab′＝E _ab?cosα (3)

As shown in Figure 4.Big more sampled value is more little, and the rate of curve table is little among Fig. 3.And scale-up factor K is the constant that time sampling is obtained by last electrical initiation, so the dolly position relative actual value of x calculated value is diminished.

This moment, Fig. 4 can see that sensor D's is less with pole lead normal angle, and reduced along with the increase of α.Difference in signal strength sampled value E with sensor D and E _DeAs coefficient k _AbCompensation join E _AbCalculating in.Formula does

${E_{\mathrm{ab}}}^{\&prime;}={k_{\mathrm{ab}}}^{\&prime;}(\frac{h}{{\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="HDA00001684575700012.png"\; state="\{\{state\}\}">h</figure-callout>}}^2+{(x-L/2)}^2}-\frac{\mathrm{<figure-callout\; id="2"\; label="h\; h"\; filenames="HDA00001684575700012.png"\; state="\{\{state\}\}">h</figure-callout>}}{h^{}})---\left(4\right)$

K wherein _Ab'=k ' E _Dek _Ab, k ' is a penalty coefficient.Under any road route, the relation of signal value and position can both satisfy the funtcional relationship of Fig. 3 like this, and position x can accurately calculate through formula 4 like this.

In the trolley travelling, when the relative guide line of dolly sensor produces deviation, can accurately obtain displacement deviation x through five sensor synergism samplings and through formula 4 and 1.Through the appropriate control algorithm accurately the servo steering wheel S0 corner φ of control make sensors A can remain on constantly guide line directly over, even the strict line walking operation of sensing system.

Have near the different proportionate relationship straight ways between control dolly front-wheel steer angle and the servo steering wheel S0 corner φ; Less with bend internal ratio coefficient, guarantee stability; Scale-up factor is bigger when getting into bend, guarantees sensitivity.As shown in Figure 5.This corresponding relation can make dolly that less adjustment amount is arranged on straight way, and the dolly traveling process is more stable.Front-wheel steer is rapid at the turning, can turn fast.The less maintenance of bend internal turn variable quantity is stable.

Sensing station, like Fig. 2 and is consistent on the front-wheel steer time and on the time of servo steering wheel at the d place in front-wheel the place ahead, and then front-wheel is leading with respect to its control of racing track variation.So in fact, run into the bend situation, dolly turns in advance, can make dolly cut bend fast, accomplishes and turns, and makes dolly actual motion route more excellent.

In the test,, on 180 ° of bends and S bend, draw its path profile respectively, calculate its path comparing result such as table 1 separately the present invention program and the contrast of traditional electrical magnetic-path navigate mode.

Two kinds of scheme path contrasts of table 1

	180 ° of bends	The S bend
			Guide line length	172cm	300cm
The tradition navigate mode	190cm	320cm
			The present invention program	160cm	250cm

Then use same gait of march when two kinds of schemes, accomplish the path of identical road conditions equal length, this programme can arrive the destination faster, and performance is superior to traditional scheme.

Claims (4)

1. navigational system based on the electromagnetic induction tracking; This system is installed on the automatic navigation vehicle, it is characterized in that, described navigational system comprises sensor groups, microprocessor, servo steering wheel, steering engine and outside support; Described servo steering wheel is located on the automatic navigation vehicle; Described servo steering wheel is connected with sensor groups through outside support, and described microprocessor is connected with servo steering wheel and sensor groups respectively, and described steering engine is connected with servo steering wheel;

The current environmental information of sensor groups induction automatic navigation vehicle; And this environmental information transferred to microprocessor; Microprocessor transmits control signal to servo steering wheel according to the environmental information that obtains; Servo steering wheel control support turns to and makes sensor groups be in the reference position always, and steering engine is according to the motion of servo steering wheel corner control automatic navigation vehicle.

2. a kind of navigational system according to claim 1 based on the electromagnetic induction tracking; It is characterized in that; Described sensor groups is formed by connecting through internal stent sensors A, sensor B, sensor C, sensor D and sensor E; Described sensor B, sensors A and sensor C are connected in turn on the internal stent equidistantly, and described sensor D is connected with sensor B, and described sensor E is connected with sensor C; Described sensor D, sensor E are symmetrical set, and all become the angle theta setting with the vertical line of sensors A, sensor B, sensor C place straight line.

3. a kind of navigational system based on the electromagnetic induction tracking according to claim 2 is characterized in that, described θ satisfies 0 °＜θ≤20 °.

4. a kind of navigational system based on the electromagnetic induction tracking according to claim 2 is characterized in that described sensors A, sensor B, sensor C, sensor D and sensor E include telefault.

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