New Product Review by TBNET | Leading SLAM Equipment Into the "Zero Processing Era"

Tech Insights12 min read

Partner product review

The involution industry is increasingly testing the innovation efficiency of hi-tech brands and business. In 2022, XGRIDS released the first mobile SLAM device for real-time solution , the Lixel L1. After two years, the newly launched flagship handheld scanning and modeling device of Lixel L2 Pro further breaks through the bottleneck of real-time computing, enhances the multi-SLAM fusion algorithm, and combines AI to bring real-time point cloud data with post-processing quality comparable to that of the previous generation products, leading SLAM equipment into the "zero processing era".

The new Lixel L2 Pro features real-time point clouds with absolute coordinates, exclusive Upsample™ algorithms, reaching 1mm point spacing, 5mm point cloud thickness , and self-developed Multi-SLAM algorithms to improve its adaptability and reliability in various scenarios, bringing a friendly and reliable new user experience. So what exactly is it like to use? Next, let's take a closer look at the device and see what surprises it can bring us.

Lixel L2 Pro handheld scanner shown on a stand outdoors on a paved plaza
Lixel L2 Pro handheld scanner shown on a stand outdoors on a paved plaza

Lixel L2 pro

I. Device Specifications and Technical Parameters

• Handheld weight: 1.7kg

• Storage capacity: 1TB

• Single battery life: 90 minutes

• Data interface: USB3.1Gen2

• Point cloud format: LAS

• Cameras: built-in color cameras 48 million ×2

• Working range: 0-120m

• Scan rate: 320,000 points/sec (16 channel)

• Device link: Use Android phone APP LixelGo and connect the device through Bluetooth hotspot

• Post-processing software:LixelStudio3.0、LccStudio1.5.0

• Special features: Visually Aided Positioning, Real-time True Color Point Cloud, Real-time RTK Fusion, Lixel CyberColor(3DGS solution)

II. Real-Time Generation of Color Point Clouds

As a new and upgraded version of the Lixel L series scanners, the Lixel L2 Pro achieves powerful real-time data processing capabilities through deep integration of LiDAR, vision, and IMU sensors, combined with AI algorithms. Color point clouds can be generated in real time without the need for external equipment, and the quality is comparable to that of last generation Lixel L2's post-processing data.

LixelStudio showing a real-time colored point cloud of a storefront building street
LixelStudio showing a real-time colored point cloud of a storefront building street
 

Project processing dialog in LixelStudio with coloring and dynamic object removal options
Project processing dialog in LixelStudio with coloring and dynamic object removal options
LixelStudio project processing settings prepared for generating a processed point cloud
LixelStudio project processing settings prepared for generating a processed point cloud

Real-Time vs. Post-Processing Point Cloud Effects

1. The point cloud filtering and smoothing are more refined, and the post-processed point cloud sorting is more regular, presenting a good light and shadow effect.

Processed point cloud of a storefront facade with a billboard after post-processing
Processed point cloud of a storefront facade with a billboard after post-processing

Real-time point cloud of a shopping plaza entrance with trees and billboards
Real-time point cloud of a shopping plaza entrance with trees and billboards

Processed point cloud of the same plaza entrance with cleaner geometry and color
Processed point cloud of the same plaza entrance with cleaner geometry and color
Garden scene comparing a real-time point cloud with a processed one that removes a moving figure
Garden scene comparing a real-time point cloud with a processed one that removes a moving figure
Processed point cloud of a landscaped garden with shrubs and flowerbeds
Processed point cloud of a landscaped garden with shrubs and flowerbeds
Wider processed point cloud of a garden with colorful planting and a stone feature
Wider processed point cloud of a garden with colorful planting and a stone feature
Top-view real-time point cloud of a garden with a flower-shaped flowerbed
Top-view real-time point cloud of a garden with a flower-shaped flowerbed

2. Post-processing can present point clouds farther away than preview real-time data.

Top-view processed point cloud of the same garden with denser detail
Top-view processed point cloud of the same garden with denser detail

Real-time point cloud of a garden plaza with a statue and blossoming trees
Real-time point cloud of a garden plaza with a statue and blossoming trees

3. Compared with the previous generation, the L2 Pro real-time point cloud can remove a number of figures, and the effect of post-processing and eliminating shadows is close to perfect.

Processed point cloud of the garden plaza with sharper foliage and surfaces
Processed point cloud of the garden plaza with sharper foliage and surfaces

Annotated point cloud of a multi-floor building showing the vertical scanning route
Annotated point cloud of a multi-floor building showing the vertical scanning route

Summary

Compared with its predecessor, the Lixel L2 Pro has achieved a qualitative leap in color point cloud generation. The original product relied on an external Insta 360 panoramic camera for point cloud coloring, which had certain limitations in the outdoor point cloud acquisition process, especially in long-term acquisition or hot weather. The panoramic camera will automatically restart due to overheating of the camera, resulting in scanning process being interrupted. With the LixelStudio3.0 new algorithm, the processed point cloud removes the excessive point density in some areas and causes excessive color, and also increases the sparseness of some areas of the point puzzle resulting in insufficient color, and the coloring effect is better.

III. Indoor Point Cloud Vertical Scanning

In the test, we started from the office door, walked vertically down six floors, scanned the corridor on the ground floor, went up six floors back to the office door, and finally scanned the inside of the office to form a closed loop. The results of the test are as follows:

1. The point cloud of real-time preview is coherent, and there is no large-scale offset and staggering.

LixelStudio measure tool checking point cloud slice thickness in a repeat-scan area
LixelStudio measure tool checking point cloud slice thickness in a repeat-scan area

2. The point cloud post-processed, and the thickness of the point cloud slice at the thinnest part is about 2mm in the area of repeated scanning.

Cross-section of a point cloud slice showing floor edges for thickness inspection
Cross-section of a point cloud slice showing floor edges for thickness inspection

3. The point post-processed, and the thickness of the point cloud slice on a single floor is about 5mm in the corridor aisle.

Elevation-colored point cloud of a six-story stairwell while defining the vertical axis
Elevation-colored point cloud of a six-story stairwell while defining the vertical axis

4. By defining the Z-axis, the six-story staircase is leveled and the offset distance is measured:

Through measurement, the north direction is offset by 1.6cm, the east direction is offset by 1.4cm, and the calculation can be √ 1.6²+√1.4²=2.13cm, and the vertical staircase is scanned, and the plane direction is offset at about 3 cm, and the effect is good.

Height-gradient point cloud of the stacked stairwell used to level the Z-axis
Height-gradient point cloud of the stacked stairwell used to level the Z-axis
Grayscale top view of an office point cloud showing clear wall outlines for CAD drafting
Grayscale top view of an office point cloud showing clear wall outlines for CAD drafting

5. The internal scanning of the office, the lines are smooth and smooth, and the point cloud is smooth/filtered with good effect.

LixelGO app in outdoor mode with the RTK account configured and connected
LixelGO app in outdoor mode with the RTK account configured and connected

Summary

In this test, the point cloud collected by the Lixel L2 Pro is smooth, the point cloud filtering effect is good, there is no obvious noise, and the line outline is clear after cutting, which can be used to draw the outline CAD drawing of the house.

IV. Topographic Scanning Point Cloud Coordinate Conversion

The Lixel L2 Pro is equipped with a high-precision RTK module, which allows you to log in to your CM or Qianxun account, connect to the CORS network, and directly output the point cloud data with absolute coordinates, with an absolute accuracy of up to 3cm.

Hand holding an RTK rover pole with a mounted controller to set a control point on a plaza
Hand holding an RTK rover pole with a mounted controller to set a control point on a plaza

Since the RTK module had not yet arrived at the time of this test, the coordinate conversion accuracy of the Lixel L2 Pro was tested by manually using the RTK to set control points. Technicians surveyed and planned the route in advance, and used RTK to evenly lay control points every 50-100 meters along the route. During the scanning, the crosswire of the instrument base is aligned with the previously laid control points at the time of the passage and added in order.

1. Manually use RTK to set control points

LixelGO app adding control points over a live point cloud during scanning
LixelGO app adding control points over a live point cloud during scanning

2. Add control points through LixelGo

LixelGO showing a height-colored real-time point cloud while scanning outdoors
LixelGO showing a height-colored real-time point cloud while scanning outdoors

3. In the process of scanning, inspect the working situation and data quality by previewing the real-time displayed point cloud and trajectory in the APP interface

Aerial view of an operator walking a site while scanning with the handheld SLAM scanner
Aerial view of an operator walking a site while scanning with the handheld SLAM scanner

When the scanner is put down to mark points, avoid the vibration caused by a large collision with the ground. When picking up the instrument after hitting the control point, pick up the instrument slowly and steadily, otherwise the strenuous action will affect accuracy. After the APP feedback that the control point is successfully added, pick up the device and rotate around the control point for 1-2 times or stay for a period of time to get a more complete point cloud around the control point.

LixelStudio dialog matching scan control points to survey coordinates for global optimization
LixelStudio dialog matching scan control points to survey coordinates for global optimization

4. Control points conversion in LixelStudio

XGRIDS control point accuracy report listing plane, elevation and spatial errors
XGRIDS control point accuracy report listing plane, elevation and spatial errors

5. Control point accuracy report

Colorized point cloud of an underground parking lot with parked cars and lane markings
Colorized point cloud of an underground parking lot with parked cars and lane markings

Summary

By converting the point cloud with relative coordinates to absolute coordinates of the measured area, the point cloud is given an absolute coordinate, and the plane and elevation conversion error is about 3 cm, which meets the accuracy requirements of topographic surveying and mapping.

V. Verification of Relative Accuracy

In order to verify the relative accuracy of Lixel L2 Pro, technicians used it to scan for point cloud data of B1 and B2 floor of an underground parking lot, and measured the edge length of the site by using an infrared laser rangefinder for comparative testing.

Floor-coded point cloud of a two-level underground parking garage
Floor-coded point cloud of a two-level underground parking garage

Colored point cloud inside the parking lot

Top view of the parking garage point cloud color-coded by basement level
Top view of the parking garage point cloud color-coded by basement level

Parking lot point cloud top view

Hand-drawn basement floor plan annotated with measured edge lengths
Hand-drawn basement floor plan annotated with measured edge lengths

Sketched basement plan marked with on-site room dimensions
Sketched basement plan marked with on-site room dimensions

The measured edge length of B1 and B2 floor

CAD overlay comparing point cloud distances with field measurements across the basement
CAD overlay comparing point cloud distances with field measurements across the basement

Comparison of the side lengths of the underground floors

CAD comparison of point cloud and tape measurements across a parking level with vehicles
CAD comparison of point cloud and tape measurements across a parking level with vehicles

Comparison of the side lengths of the B2

Table comparing rangefinder distances with point cloud measurements and their differences
Table comparing rangefinder distances with point cloud measurements and their differences

Error comparison

Point No.LevelInfrared Distance Measured (m)Point Cloud Model (m)Difference (m)Absolute Difference (m)
1B11.5471.549-0.0020.002
2B12.3222.3170.0050.005
3B12.1892.1820.0070.007
4B16.3586.3480.010.01
5B14.0023.9680.0340.034
6B13.673.6700
7B14.4134.432-0.0190.019
8B15.1385.1280.010.01
9B113.52513.5220.0030.003
10B26.9716.983-0.0120.012
11B210.39310.3850.0080.008
12B26.1166.0930.0230.023
13B27.4537.466-0.0130.013
14B25.535.531-0.0010.001
15B25.8085.80.0080.008
16B26.3026.306-0.0040.004
17B25.1325.1070.0250.025
18B211.55211.540.0120.012
19B24.8124.81200
20B25.5085.518-0.010.01
21B24.694.6900
22B27.9037.8940.0090.009
23B22.8142.8090.0050.005
24B26.9746.989-0.0150.015
25B24.8014.816-0.0150.015
Average Error Value0.01

Summary

The results show that the absolute difference between the point cloud measurement and the field measurement is controlled at about 3 cm, and the average error value is plus or minus 1 cm, which is good. The product can present a good point cloud smooth post-processing effect in the underground space, and can be used to draw the outline plan of the basement and civil air defense space.

VI. Upsample™ Algorithm

Exclusive Upsample™ point cloud algorithm makes the point cloud spacing 5mm after post-processing, while the matrix is evenly arranged.

True-color point cloud of a roundabout flowerbed with a circular signpost
True-color point cloud of a roundabout flowerbed with a circular signpost

5 mm matrix point cloud

Densified point cloud of the same roundabout flowerbed after Upsample post-processing
Densified point cloud of the same roundabout flowerbed after Upsample post-processing
 

Real-time true-color point cloud

Point cloud of an illuminated jazz festival billboard showing fine text and portrait detail
Point cloud of an illuminated jazz festival billboard showing fine text and portrait detail

5mm post-processing point cloud through  Upsample™

Upsampled point cloud of the festival billboard with enhanced density and color
Upsampled point cloud of the festival billboard with enhanced density and color

Real-time true-color point cloud

TBNET company logo
TBNET company logo

5mm post-processing point cloud through Upsample™

Summary

The exclusive Upsample™ enhancement algorithm of Lixel L2 Pro further enhances the point cloud density and structural details, combined with ultra-high coloring accuracy, so that the color point cloud effect reaches a photographic level, which can accurately capture every detail, allowing users to accurately reproduce the real scene and realize "what you get is what you see".

To Conclude

Overall, as a flagship-level handheld scanning and modeling device, the Lixel L2 Pro performs well in terms of hardware specifications, scanning performance, and data processing. It not only provides users with more efficient and accurate scanning solutions, but also injects new vitality into the development of 3D intelligent technology through the introduction of innovative technologies such as seamless point clouds. If you're looking for a handheld SLAM product that can handle a variety of complex scenarios and provide high-quality scan data, then the Lixel L2 Pro is definitely an option worth considering.

About TBNET

TBNET brand logo
TBNET brand logo

Founded in 2001, TBNET is a leading provider of positioning and 3D visualization products and solutions in China, and is committed to the sales and service of surveying and mapping optical products, 3D laser measurement systems, GNSS positioning services and equipment, marine surveying and building construction products in China. It is a national high-tech enterprise, a specialized and new "little giant" enterprise in Hubei Province, an enterprise research and development center in Wuhan, and one of the first batch of digital economy service resource pool enterprises in Wuhan.

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