CN102662401B - 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 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 electromagnetic induction tracking.

Background technology

Automatic navigation vehicle (Automated Guided Vehicles, AGV) be called again automatic guided vehicle, come across the earliest the 1950's, it is a kind of unpiloted intelligent haulage equipment of robotization, belong to mobile robot system, can travel along predefined path, be the visual plant of modernization industry automatic Material Handling System.Moreover, in military affairs and hazardous area, the automatic Pilot of AGV of take is that basis inherits other detections and detaching equipment, 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 form.Wherein, orientation sensor is perception path in AGV, the key modules of controlling walking path, and its sensitivity and dirigibility have determined the work efficiency of AGV dolly to a great extent.At present, conventional guiding sensing mode is generally laser navigation mode, ultrasound wave navigation mode, vision guided navigation mode (being CCD sensing mode) and electromagnetic induction navigate mode.

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

Summary of the invention

Object of the present invention is exactly that the navigational system based on electromagnetic induction tracking of the operational efficiency of a kind of AGV of raising under pahtfinder hard is provided in order to overcome the defect of above-mentioned prior art existence.

Object of the present invention can be achieved through the following technical solutions:

A kind of navigational system based on electromagnetic induction tracking, this system is installed on automatic navigation vehicle, described navigational system comprises sensor group, microprocessor, Servo-controller, steering engine and outside support, described Servo-controller is located on automatic navigation vehicle, described Servo-controller is connected with sensor group by outside support, described microprocessor is connected with Servo-controller and sensor group respectively, and described steering engine is connected with Servo-controller;

The current environmental information of sensor group induction automatic navigation vehicle, and this environmental information is transferred to microprocessor, microprocessor transmits control signal to Servo-controller according to the environmental information obtaining, Servo-controller control support turns to and makes sensor group always in reference position, and steering engine is according to the motion of Servo-controller controlling angle automatic navigation vehicle.

Described sensor group is formed by connecting by internal stent by sensors A, sensor B, sensor C, sensor D and sensor E, described sensor B, sensors A and sensor C are connected in turn in internal stent equidistantly, described sensor D is connected with sensor B, described sensor E is connected with sensor C, described sensor D, sensor E are symmetrical arranged, and all become angle theta setting with the vertical line of sensors A, sensor B, sensor C place straight line.

Described θ meets 0 ° of < θ≤20 °.

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

Compared with prior art, the present invention is by adopting special sensor installation method to propose a kind of new navigational system based on electromagnetic induction tracking, device by the sensor group that formed by five sensors 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 poor E of the accurate compensating potential of difference in signal strength sampled value of sensor D and E _ab, particularly, when bend, more improved the operational efficiency of AGV.

Accompanying drawing explanation

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

Fig. 2 is the relative position schematic diagram of five sensors of sensor group 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 group axis and guide line;

Fig. 5 is Servo-controller corner and AGV front wheel angle corresponding relation.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.

Embodiment

As Figure 1-Figure 2, a kind of navigational system based on electromagnetic induction tracking, this system is installed on automatic navigation vehicle AGV, described navigational system comprises sensor group, microprocessor, Servo-controller S0, steering engine and outside support, described Servo-controller is located on automatic navigation vehicle, described Servo-controller is connected with sensor group by outside support, and described microprocessor is connected with Servo-controller and sensor group respectively, and described steering engine is connected with Servo-controller.The principle of work of above-mentioned navigational system is: the current environmental information of sensor group induction automatic navigation vehicle, and this environmental information is transferred to microprocessor, microprocessor transmits control signal to Servo-controller according to the environmental information obtaining, Servo-controller control support turns to and makes sensor group always in reference position, and steering engine is according to the motion of Servo-controller controlling angle automatic navigation vehicle.

As Figure 1-Figure 2, described sensor group is formed by connecting by support by sensors A, sensor B, sensor C, sensor D and sensor E, described sensor B, sensors A and sensor C are connected in turn on same support equidistantly, described sensor D is connected with sensor B, described sensor E is connected with sensor C, described sensor D, sensor E are symmetrical arranged, and meet 0 ° of < θ≤20 ° with the vertical line angle θ of sensors A, sensor B, sensor C place straight line.Five sensors of described sensor group form by telefault.Five sensors are fixed by support, and be arranged on Servo-controller S0.The distance that sensor group is stretched out vehicle body is d, and height is overhead 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 for x, 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 formula, k _abfor constant.If h=10, L=20, k _ab=10, the relation of sampled value and x as shown in Figure 3.Curve can be found out as shown in Figure 3, between (10,10) lane place, and sampled value E _abx is approximately proportionate relationship with position, and establishing its coefficient is K, and the sampled value that K can be powered on constantly in system by middle sensors A obtains.During actual motion, by systematic sampling, obtain E _ab, so now x can pass through formula

x＝E _ab/K (2)

Obtain.At trolley travelling, near bend time, the angle of establishing between sensors A, B and C coil axis and the normal of lead wire is α, according to magnetic flux principle now

E _ab′＝E _ab cosα (3)

As shown in Figure 4.Larger sampled value is less, and in Fig. 3, rate of curve table is little.And Proportional coefficient K is the constant that time sampling is obtained by upper electrical initiation, so the dolly position relative actual value of x calculated value is diminished.

Now Fig. 4 can see, sensor D's is less with pole wire normal angle, and reduces along with the increase of α.By the difference in signal strength sampled value E of sensor D and E _deas coefficient k _abcompensation join E _abcalculating in.Formula is

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

K wherein _ab'=k ' E _dek _ab, k ' is penalty coefficient.Under any road route, the relation of signal value and position can meet the funtcional relationship of Fig. 3 like this, and position x can accurately calculate by formula 4 like this.

In trolley travelling, when the relative guide line of dolly sensor produces deviation, by five sensor synergisms, sample and can accurately obtain displacement deviation x by formula 4 and 1.By suitable control algolithm accurately control Servo-controller S0 corner φ make sensors A can remain on constantly guide line directly over, even the operation of the strict line walking of sensing system.

Control dolly front-wheel steer angle

near having different proportionate relationship straight ways between Servo-controller S0 corner φ, and bend internal ratio coefficient is less, guarantees stability; While entering bend, scale-up factor is larger, guarantees sensitivity.As shown in Figure 5.This corresponding relation, can make dolly on straight way, have less adjustment amount, and dolly traveling process is more stable.At turning, front-wheel steer is rapid, can turn fast.The less maintenance of bend internal turn variable quantity is stable.

Sensing station is at the d place in front-wheel the place ahead, and as Fig. 2, and the front-wheel steer time is upper and be consistent on the time of Servo-controller, and with respect to racing track, to change its control be leading to front-wheel.So in fact, run into bend situation, dolly turns in advance, can make dolly cut fast bend, completes turning, makes dolly actual motion route more excellent.

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

The contrast of table 1 two schemes path

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

, when two schemes is used same gait of march, complete the path of identical road conditions equal length, this programme can arrive destination faster, and performance is better than traditional scheme.

Claims (2)

1. the navigational system based on electromagnetic induction tracking, this system is installed on automatic navigation vehicle, it is characterized in that, described navigational system comprises sensor group, microprocessor, Servo-controller, steering engine and outside support, described Servo-controller is located on automatic navigation vehicle, described Servo-controller is connected with sensor group by outside support, and described microprocessor is connected with Servo-controller and sensor group respectively, and described steering engine is connected with Servo-controller;

Described sensor group is formed by connecting by internal stent by sensors A, sensor B, sensor C, sensor D and sensor E, described sensor B, sensors A and sensor C are connected in turn in internal stent equidistantly, described sensor D is connected with sensor B, described sensor E is connected with sensor C, described sensor D, sensor E are symmetrical arranged, and all become angle theta setting with the vertical line of sensors A, sensor B, sensor C place straight line;

Described θ meets 0 ° of < θ≤20 °;

The current environmental information of sensor group induction automatic navigation vehicle, and this environmental information is transferred to microprocessor, microprocessor transmits control signal to Servo-controller according to the environmental information obtaining, Servo-controller control support turns to and makes sensor group always in reference position, and steering engine is according to the motion of Servo-controller controlling angle automatic navigation vehicle.

2. a kind of navigational system based on electromagnetic induction tracking according to claim 1, is characterized in that, described sensors A, sensor B, sensor C, sensor D and sensor E include telefault.

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