OMRON Z500 high-precision contour measurement system

OMRON Z500 high-precision contour measurement system

Introduction: Technical bottlenecks and alternative needs of traditional contour measurement

In the process of industrial automation manufacturing, high-precision measurement of object contours is a key link in quality control. Traditional non-contact measurement methods usually rely on point displacement sensors to obtain height data by moving the measured object or the sensor itself. However, this approach exposes multiple systemic flaws in practical applications:

Mechanical motion introduces errors: Whether it is moving objects or sensors, measurement accuracy will decrease due to factors such as clearance, vibration, and uneven speed in the guidance system.

The system construction cost is high: it requires precision motion platforms and complex control systems, which increases equipment investment and maintenance costs.

Low measurement efficiency: The point by point scanning method is difficult to meet the real-time detection requirements of high-speed production lines.

To solve the above problems, a line beam method based on wide beam projection and two-dimensional CCD image sensing has emerged. This method can obtain the complete two-dimensional contour information of a certain section of an object at once without the need for relative motion, and has the characteristics of high accuracy, high stability, and high efficiency.

The working principle and system composition of the line beam method

2.1 Technical Principles

The core of the line beam method is to project a wide beam (line laser) onto the surface of the object being measured, and the reflected light is received by a two-dimensional CCD. The system analyzes the position distribution of reflected light on the CCD, calculates the height information of each point on the surface of the object, and reconstructs the two-dimensional contour.

Compared to traditional displacement sensors that can only obtain the height of "points", the line beam method directly obtains the contour of "lines", avoiding errors caused by mechanical scanning. The key advantages of this technology include:

No need to move: The measurement can be completed when the object and sensor are relatively stationary.

Wide adaptability: suitable for specular reflection, diffuse reflection, surfaces of different colors and materials.

High speed response: Fixed sampling period, suitable for dynamic process monitoring.

2.2 System composition

A typical line beam measurement system consists of the following components:

Sensor head: emits line laser and receives reflected light, with a built-in two-dimensional CCD.

Controller: processes image data, executes measurement algorithms, and outputs results.

Display screen (optional): Real time display of contour images, trend charts, numerical values, etc.

Cables and accessories: including sensor extension cables, monitoring cables, ferrite magnetic rings, etc.

The controller supports multiple input and output modes, including RS-232C, analog output (voltage or current), and digital IO trigger control. Its analog output resolution can reach 1/40000, with extremely high signal accuracy.

Detailed Product Series and Performance Parameter Interpretation

The following is a detailed specification of a typical line beam measurement system (such as OMRON Z500 series), covering key technical parameters such as measurement mode, distance, range, resolution, and light source type for different models.

3.1 Model Classification and Applicable Scenarios

According to the measurement distance and range, it is mainly divided into the following three sub models:

Model Mode Measurement Center Distance Measurement Range Applicable Scenarios

SW2T diffuse reflection/mirror reflection 5.2 mm/20 mm ± 0.8 mm/± 5 mm ultra precision close range detection

SW6 diffuse reflection/mirror reflection 50 mm/44 mm ± 4 mm/± 20 mm universal industrial testing

SW17 diffuse/mirror reflection 100 mm/94 mm ± 16 mm/± 16 mm long distance, wide range detection

3.2 Light source characteristics

SW2T: wavelength 650 nm, maximum output 1 mW, Class 2 laser.

SW6/SW17: wavelength 658 nm, maximum output 15 mW, Class 3B laser.

Note: Higher power lasers are available for special applications, please contact the supplier.

3.3 Beam size and measurement area

SW2T: 20 μ m × 4 mm (measurement area 2 mm)

SW6: 30 μ m × 24 mm (measurement area 6 mm)

SW17: 60 μ m × 45 mm (measurement area 17 mm)

3.4 Linearity and Resolution

Linearity: All models are ± 0.1% F.S. (full scale), but the reference material is different:

SW2T: Quartz glass (mirror) or SUS block (diffuse reflection)

SW6: SUS block

SW17: White alumina ceramic

Resolution:

SW2T: 0.25 μ m (average number of times 16)

SW6: 0.3 μ m (average number of times 64)

SW17:1.0 μ m (average number of times 64)

Attention: Resolution may decrease in strong magnetic field environments.

3.5 Sampling period and environmental adaptability

Fixed sampling period: 9.94 ms, suitable for real-time dynamic detection.

Temperature characteristics: 0.01% F.S./° C

Protection level:

SW2T：IP64

SW6/SW17: IP66 (better protection)

Work environment:

Temperature: 0-50 ° C

Humidity: 35-85% RH

Vibration: 10-150 Hz, double amplitude 0.35 mm

Illumination: Receiving surface illumination ≤ 3000 lx (incandescent lamp)

3.6 Other physical parameters

Cable length: SW2T (2 m), SW6 (0.5 m), SW17 (2 m)

Minimum bending radius: 68 mm

Weight: 600-800 g (including packaging)

Material: Die cast aluminum body, heat-resistant vinyl chloride cable, zinc alloy+brass connector

Four major monitoring modes and their engineering applications

In the actual testing process, the system provides four different data display methods for engineers to choose according to their needs:

4.1 Profile Monitor

Displaying the changes in contour over time in the form of 3D grayscale images is suitable for analyzing the dynamic evolution of cross-sectional height, such as changes in welding pool shape, uniformity of sealant application, etc.

4.2 Image Monitor

Simultaneously displaying measurement data and contour images facilitates on-site operators to intuitively understand the correspondence between measurement results and physical objects.

4.3 Digital Monitor

Simultaneously displaying the values of multiple measurement items, such as height difference, step height, edge position, etc., is suitable for numerical comparison in batch testing.

4.4 Trend Monitor

Display the trend of measurement data over time, suitable for process stability analysis, such as shrinkage changes during injection molding.

Controller functions and data processing capabilities

The controller is the computational core of the entire system and possesses the following key capabilities:

5.1 Measurement Items

Supports multiple measurement types:

height

Two point step height (Step: 2 pts)

Three point step height (Step: 3 pts)

Edge position

width

Edge center

Peak/valley value

5.2 Data Storage and Triggering

Storage points: up to 2048 points

Trigger method:

free running

External trigger 1/2

Automatic judgment output

5.3 Output Interface

RS-232C: Measurement value output

Terminal output: 11 point input (such as trigger, reset, D10-D17), 21 point output (D00-D019, GATE)

Analog output: ± 5 V (resolution 0.25 mV) or 4-20 mA (resolution 0.4 μ A)

5.4 Electrical and Environmental Parameters

Power supply: 21.6-26.4 VDC

Current consumption: ≤ 1 A (connected to two sensors)

Insulation resistance: ≥ 20 M Ω (100 VDC)

Voltage resistance: 1000 VAC, 1 minute

Noise resistance: 1500 Vp-p

Impact resistance: 200 m/s ²

5.5 Display specifications

Screen: 5.5-inch TFT color LCD

Resolution: 320 × 240

Input signal: NTSC composite video

Power supply: 20.4-26.4 VDC

Power consumption: approximately 700 mA

Installation, wiring, and laser safety regulations

6.1 Installation precautions

Sensors and controllers should be installed in an environment free from corrosive gases and strong magnetic field interference.

The grounding resistance must be less than 100 Ω.

The minimum bending radius of the cable is 68 mm to avoid signal interference.

6.2 Requirements for safe use of lasers

Due to the involvement of Class 2 or Class 3B lasers in the system, the following specifications must be strictly followed:

Strictly follow the operation manual to avoid direct exposure to the laser beam.

Ensure that the laser path is absorbed or terminated at the terminal to avoid the harm of reflected light.

If using a mirror reflective object, the path of the reflected light must be controlled.

Do not disassemble or remove the protective casing.

All repairs must be completed by the original factory or authorized personnel.

Laser warning labels must be clearly visible.

When used in different countries, comply with local laser safety regulations.

Common troubleshooting and engineering recommendations

7.1 Measurement value fluctuation or instability

Possible reasons:

Strong magnetic field interference

Multiple reflections caused by reflective surfaces

Excessive ambient lighting (>3000 lx)

Solution:

Increase the average number of measurements (e.g. from 16 to 64)

Use a light shield or change the measurement mode (mirror → diffuse reflection)

Adjust the sensor angle to avoid mirror reflection

7.2 Linearity exceeds specifications

Possible reasons:

The difference between the tested material and the calibration reference material is too large

Sensor lens contamination

Solution:

Re calibrate using standard blocks that are similar to the actual workpiece material

Clean the lens to avoid the influence of dust or oil stains

7.3 Unable to trigger or output abnormality

Possible reasons:

Mismatch in trigger signal level

Poor grounding of power supply

Solution:

Check the external trigger voltage range (should be compatible with the controller)

Confirm that the grounding resistance is ≤ 100 Ω

7.4 Error caused by temperature drift

Solution:

Use temperature compensation function (0.01% F.S./° C)

Using aluminum fixtures to stabilize heat conduction between sensors and the measured object

Application Cases and Selection Suggestions

8.1 Typical Applications

Coplanarity detection of electronic component pins: Use SW2T with a resolution of 0.25 μ m to detect the height difference of connector terminals.

Rubber sealing strip contour detection: using SW6, measuring width ± 20 mm, suitable for the reflection characteristics of soft materials.

Edge positioning of lithium battery electrode coating: using SW17, long working distance to avoid interference with the coating process.

8.2 Selection Suggestions

Reason for recommending the required model

Ultra high precision (μ m level) SW2T has the highest resolution and a small measurement range

General industrial testing SW6 balance resolution and measurement range

Large range/long-distance SW17 suitable for large workpieces or limited installation space