CN102607462B - Three-dimensional laser scanning signal synchronization and correction method - Google Patents

Abstract

The output signal of a laser ranging sensor is decoded by using a programmable logic device (FPGA) to obtain the distance L of measured points, the included angles alpha and beta of a scanning optical axis OE and two scanning shafts are synchronously collected and amended, and the three-dimensional spatial coordinate (x, y, z) of a scanned point E is calculated according to the geometric relationship. A UART synchronous monitoring and decoding module, a horizontal axis angle decoding module, a vertical axis angle decoding module, a horizontal axis rotational speed calculating module, a vertical axis rotational speed calculating module, a latch, an angular position correcting module and a data outputting interface are adopted by a three-dimensional laser scanning signal synchronization and correction method. The functions of all parts are fulfilled by the programmable logic device (FPGA). The three-dimensional laser scanning signal synchronization and correction method can realize the rapid synchronization of the angular position of a scanning rotating shaft and the high-precision data of a laser ranging module rapidly without outputting synchronous signals by the laser ranging module, ensures the modularized functions, is easy to operate and improves the data synchronization accuracy.

Description

Synchronous and the modification method of a kind of 3 D laser scanning signal

Technical field

The present invention relates to a kind of laser distance measurement method, relate to more specifically a kind of 3 D laser scanning signal synchronously and modification method.Synchronize with the high accuracy data of laser ranging module in the angle position of realizing scanning turning axle.Be widely used in 3 D laser scanning equipment.

Background technology

Portable high-accuracy three-dimensional laser scanner is optical, mechanical and electronic integration highly sophisticated device equipment, is a new and high technology of immediate development in the world.It is the principle of utilizing laser ranging, by recording three-dimensional coordinate information and the reflectivity information of a large amount of intensive point in testee surface, by complete the collecting in computer of the three-dimensional data of various large entities or outdoor scene, and then rebuild out fast the various figure event data such as the three-dimensional model of measured target and line, face, body, not only save time but also laborsaving, this ability is that existing 3 d modeling software is incomparable.

An important indicator of portable high-accuracy three-dimensional laser scanner is measuring accuracy, synchronizeing with the high accuracy data of laser ranging module in the angle position of scanning turning axle is the precondition that guarantees measuring accuracy, if the synchronous degree of accuracy of data is not high, be difficult to realize more high-precision measurement.

But, existing three-dimensional laser scanner, the scanning angle position of turning axle and the high accuracy data synchronous effect of laser ranging module are not generally very good.

Summary of the invention

The object of the invention is to propose the synchronous and modification method of a kind of 3 D laser scanning signal.Synchronize with the high accuracy data of laser ranging module in the angle position of realizing scanning turning axle.Be widely used in 3 D laser scanning equipment.

For achieving the above object, adopt following technical scheme:

Synchronous and the modification method of signal, the steps include:

A, UART synchronization monitoring and decoding:

Utilize programmable logic device (PLD) (FPGA) that the output signal of laser range sensor is gathered and decoded, and after the valid data L of laser range sensor being detected, export a synchronizing signal Sync, be used for synchronously latching angle α ', β ' and the rotational speed omega of two scan axises corresponding to this moment _α, ω _β, the time delay that this moment is carved with a δ while triggering with respect to the actual measurement of laser range sensor, by adjusting the synchronization accuracy of data to the adjustment of δ parameter;

B, the decoding of transverse axis angle:

Utilize programmable logic device (PLD) (FPGA) to decode to the angular encoder signal of horizontal scanning axle, obtain the real-time angular position information α ' of horizontal scanning axle;

C, the decoding of Z-axis angle:

Utilize programmable logic device (PLD) (FPGA) to decode to the angular encoder signal of vertical scanning axle, obtain the real-time angular position information β ' of vertical scanning axle;

D, transverse axis rotating speed calculate:

Utilize programmable logic device (PLD) (FPGA) to calculate the angle-data of the angle decoding output of horizontal scanning axle, draw the rotational speed omega of horizontal scanning axle _α, utilize the rotational speed omega of horizontal scanning axle _αdata are also carved with a time delay δ while triggering with respect to the actual measurement of laser range sensor in conjunction with the Sync signal of UART synchronization monitoring and decoding output, can realize the correction of data synchronization accuracy;

E, Z-axis rotating speed calculate:

Utilize programmable logic device (PLD) (FPGA) to calculate the angle-data of the angle decoding output of vertical scanning axle, draw the rotational speed omega of vertical scanning axle _β, utilize the rotational speed omega of vertical scanning axle _βdata are also carved with a time delay δ while triggering with respect to the actual measurement of laser range sensor in conjunction with the Sync signal of UART synchronization monitoring and decoding output, realize the correction of data synchronization accuracy;

F, transverse axis data latch:

Utilize programmable logic device (PLD) (FPGA) to realize latch, be used for latching the angle decoding of horizontal scanning axle and velocity gauge and calculate corresponding to UART synchronization monitoring and the angle [alpha] in the decoding output Sync moment ' and rotational speed omega _α;

G, Z-axis data latch:

Utilize programmable logic device (PLD) (FPGA) to realize latch, be used for latching the angle decoding of vertical scanning axle and velocity gauge and calculate corresponding to UART synchronization monitoring and the angle beta in the decoding output Sync moment ' and rotational speed omega _β;

H, angle position are revised:

By the angle [alpha] latching ' and rotational speed omega _αdata, the angle beta latching ' and rotational speed omega _β, according to α=α '-δ * ω _α, β=β '-δ * ω _βformula calculates, and realizes the adjustment of data synchronization accuracy by adjusting delay parameter δ, realizes the correction to data synchronization accuracy;

I, data output:

The angle-data α of the distance L that laser range sensor is recorded, revised two scan axises, β is according to required data layout output.

Principle of the present invention is:

Utilize programmable logic device (PLD) (FPGA) to decode to the output signal of laser range sensor, draw measured point distance L; Synchronous acquisition is also revised the scanning optical axis OE of laser ranging module and the angle α of two scan axises, and β (as shown in Figure 1) utilizes geometric relationship to calculate to be scanned the three dimensional space coordinate (x, y, z) of an E.

$\left\{\begin{array}{c}x=L*\cos \mathrm{\β}*\sin \mathrm{\α}\\ y=L*\cos \mathrm{\β}*\cos \mathrm{\α}\\ z=L*\sin \mathrm{\β}\end{array}\right.$

The method consists of following part: UART synchronization monitoring and decoder module; Transverse axis angle decoder module; Z-axis angle decoder module; Transverse axis rotating speed computing module; Z-axis rotating speed computing module; Latch; Angle position correcting module; And data output interface.Various piece function is all realized by programmable logic device (PLD) (FPGA).

Compared with prior art, tool of the present invention has the following advantages and beneficial effect:

1, by programmable logic device (PLD) (FPGA), the output signal of laser range sensor is decoded and produced synchronizing signal.

2, utilize programmable logic device (PLD) (FPGA) to decode to two scanning turning axle upper angle scramblers, draw angle position data α ', the β ' of two scanning turning axles.

3, utilize programmable logic device (PLD) (FPGA) to decode to two scanning turning axle upper angle scramblers, calculate the rotational speed ω of two scanning turning axles _α, ω _β.

4, according to synchronizing relay parameter δ, can press formula α=α '-δ * ω to the angle position of two scanning turning axles _α, β=β '-δ * ω _βrevise, by realizing the adjustment to data synchronization accuracy to the adjustment of synchronizing relay parameter δ.

5, the present invention is simple in structure, cheap, and all functions all adopt programmable logic device (PLD) (FPGA) to realize.

6, it is synchronous that the synchronizing signal that does not need laser ranging module to export is carried out data.

7, synchronization accuracy can regulate by parameter δ, can realize high accuracy data synchronous.

8, all functions modularization, is convenient to realization and product systems integrated.

As mentioned above, when adopting in three-dimensional laser scanning system when of the present invention, synchronizeing with the high accuracy data of laser ranging module in the angle position that can realize fast scanning turning axle, and does not need laser ranging module output synchronizing signal, so this invention can take into account all laser ranging modules.By adjusting parameter δ, can adjust the synchronous degree of accuracy of data, all functions modularization, therefore have simple to operate, improve the synchronous regulated efficiency of data, improve the texts such as data accuracy of synchronism.

Accompanying drawing explanation

Fig. 1 is a kind of 3 D laser scanning principle schematic.

Fig. 2 is a kind of programmable logic device (PLD) inner function module schematic diagram.

Embodiment

Embodiment 1:

As shown in Figure 2, the synchronous and modification method of described 3 D laser scanning signal specifically comprises: UART synchronization monitoring and decoder module 12; Transverse axis angle decoder module 10; Z-axis angle decoder module 11; Transverse axis rotating speed computing module 20; Z-axis rotating speed computing module 21; Latch 30 and 31; Angle position correcting module 40; And data output interface 41.Various piece function is all realized by programmable logic device (PLD) (FPGA).

Wherein, the output signal of described UART synchronization monitoring and 12 pairs of laser range sensors of decoder module gathers and decodes, and after the valid data L of laser range sensor being detected, export a synchronizing signal Sync, signal Sync is synchronized to latch 30 and 31 simultaneously, latch starts angular position information and rotary speed data to latch, the time delay that this moment is carved with a δ while triggering with respect to the actual measurement of laser range sensor.

Wherein, the angular encoder signal of 10 pairs of horizontal scanning axles of described transverse axis angle decoder module is decoded, and obtains the real-time angular position information α ' of horizontal scanning axle, angular position information α ' is delivered to latch 30 simultaneously.

Wherein, the angular encoder signal of 11 pairs of vertical scanning axles of described Z-axis angle decoder module is decoded, and obtains the real-time angular position information β ' of vertical scanning axle, angular position information β ' is delivered to latch 31 simultaneously.

Wherein, the angle-data of the angle of 20 pairs of horizontal scanning axles of described transverse axis rotating speed computing module decoding output calculates, and draws the rotational speed omega of horizontal scanning axle _α, simultaneously by the rotational speed omega of horizontal scanning axle _αdeliver to latch 30.

Wherein, the angle-data of the angle of 21 pairs of vertical scanning axles of described Z-axis rotating speed computing module decoding output calculates, and draws the rotational speed omega of vertical scanning axle _β, simultaneously by the rotational speed omega of vertical scanning axle _βdeliver to latch 31.

Then, the angle [alpha] in 40 pairs of latchs 30 of described angle position correcting module ' and rotational speed omega _α, to the angle beta in latch 31 ' and rotational speed omega _β, according to formula α=α '-δ * ω _α, β=β '-δ * ω _βcalculate, by adjusting delay parameter δ, realize the adjustment of data synchronization accuracy, realize the correction to data synchronization accuracy.

Finally, the distance L that described data output interface 41 records laser range sensor, the angle-data α of revised two scan axises, β is according to required data layout output.

Claims (1)

1. the synchronous and modification method of 3 D laser scanning signal, the steps include:

A, UART synchronization monitoring and decoding:

Utilize programmable logic device (PLD) (FPGA) that the output signal of laser range sensor is gathered and decoded, and after the range data L that laser range sensor records being detected, export a synchronizing signal Sync, be used for synchronously latching angle α ', β ' and the rotational speed omega of two scan axises corresponding to this moment _α, ω _β, the time delay that this moment is carved with a δ while triggering with respect to the actual measurement of laser range sensor, by the adjustment to δ parameter, realizes the correction of data synchronization accuracy;

B, the decoding of transverse axis angle:

Utilize programmable logic device (PLD) (FPGA) to decode to the angular encoder signal of horizontal scanning axle, obtain the real-time angular position information α ' of horizontal scanning axle;

C, the decoding of Z-axis angle:

Utilize programmable logic device (PLD) (FPGA) to decode to the angular encoder signal of vertical scanning axle, obtain the real-time angular position information β ' of vertical scanning axle;

D, transverse axis rotating speed calculate:

Utilize programmable logic device (PLD) (FPGA) to calculate the angle-data of the angle decoding output of horizontal scanning axle, draw the rotational speed omega of horizontal scanning axle _α, utilize the rotational speed omega of horizontal scanning axle _αdata are also carved with a time delay δ while triggering with respect to the actual measurement of laser range sensor in conjunction with the Sync signal of UART synchronization monitoring and decoding output, realize the correction of data synchronization accuracy;

E, Z-axis rotating speed calculate:

Utilize programmable logic device (PLD) (FPGA) to calculate the angle-data of the angle decoding output of vertical scanning axle, draw the rotational speed omega of vertical scanning axle _β, utilize the rotational speed omega of vertical scanning axle _βdata are also carved with a time delay δ while triggering with respect to the actual measurement of laser range sensor in conjunction with the Sync signal of UART synchronization monitoring and decoding output, realize the correction of data synchronization accuracy;

F, transverse axis data latch:

Utilize programmable logic device (PLD) (FPGA) to realize latch, the angle decoding and the velocity gauge that are used for latching horizontal scanning axle are calculated corresponding to UART synchronization monitoring and angle [alpha] ' and the rotational speed omega in the decoding output Sync moment _α;

G, Z-axis data latch:

Utilize programmable logic device (PLD) (FPGA) to realize latch, the angle decoding and the velocity gauge that are used for latching vertical scanning axle are calculated corresponding to UART synchronization monitoring and the angle beta in the decoding output Sync moment ' and rotational speed omega _β;

H, angle position are revised:

By the angle [alpha] latching ' and rotational speed omega _αdata, the angle beta latching ' and rotational speed omega _β, according to α=α '-δ * ω _α, β=β '-δ * ω _βformula calculates, and realizes the adjustment of data synchronization accuracy by adjusting delay parameter δ, realizes the correction to data synchronization accuracy;

I, data output:

The angle-data α of the distance L that laser range sensor is recorded, revised two scan axises, β is according to required data layout output.

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