In the metal industry, precise measurement of length, distance, and position It is necessary in numerous cutting, feeding, positioning, and material handling processes. laser distance sensors They allow these measurements to be taken without physical contact and the value to be transmitted directly to the PLC or machine control system.
This technology can be used both in cutting machines for bars, tubes and profiles such as in steel production lines, cutting-to-length systems, positioning of stops and carriages, dimensional control of slabs and other industrial automation applications.
The main advantage is having an absolute reference for position or distance without mechanical elements in contact with the part, avoiding problems associated with the wear of measuring wheels, cables, rulers or certain mechanical positioning systems.
Applications of laser sensors in metal cutting and production
Depending on the machine's geometry, a laser sensor can directly measure the position of the workpiece or a moving element and use that information to determine when to cut, position a stop, or verify a dimension.
| Process | Measured variable | Laser sensor application |
|---|---|---|
| Cut to length / Cut-to-Length | Position or length | Determine the position of the material before making the cut |
| Automatic saw | Part or stop position | Positioning for cutting bars, tubes or profiles |
| Shears | Material position | Reference for cross section or formats |
| Cart or movable stop | Absolute position | Position feedback to the PLC |
| Slabs and roughing | Length, thickness, width, or position | Dimensional control and positioning on the line |
| Transport lines | Presence and position | Tracking large pieces of steel |
| Special machines | Distance | Retrofit or replacement of certain mechanical measuring systems |
Cut-to-length control (CTL)
In processes of cut to length either Cut-to-Length (CTL), The objective is to obtain pieces or formats with a specific length from sheet metal, bars, profiles, tubes, or other metal products.
In an automated line, the laser sensor can be installed in a fixed position and measure the distance to the end of the material, a stop, a feed carriage, or another moving reference point. The PLC uses this distance to determine the position and decide when the programmed cutting point has been reached.
The relationship between measured distance and length depends on the geometry of the installation. For example, if the sensor knows a fixed reference distance, the position of the end of the part can be calculated from the variation relative to that reference.
This principle is particularly interesting in applications where mechanical contact with the material is to be avoided or where an absolute measurement is needed after a stop, restart, or format change.
Dimetix has a specific industrial application, AE-0509 Laser controlled cut-off solution, Developed for a steel production facility, the system used a Dimetix laser sensor, linear drive, and PLC control to automate a steel bar cutting solution using an industrial saw.
Measuring bars, tubes and profiles on cutting machines
Automatic saws and other cutting machines need to correctly position the material before starting each cycle. A laser sensor can be used in these types of machines to measure the position of the end of a bar, tube, profile or long piece.
The measurement can be shown to the operator for reference or sent directly to the control system to automate positioning.
Compared to manual measurement using a ruler, tape measure, or visual reference, automatic reading allows for reduced operator intervention and maintains a repeatable reference between production cycles.
In newly constructed machinery, it also allows the manufacturer to directly incorporate the position measurement into the PLC, while in certain projects of machinery retrofit It can be used to modernize existing measurement systems.
Measurement of steel slabs and large products in steelmaking
In a steel mill or steel plant, measurement needs extend beyond simply cutting an individual piece. During the production and transport of slabs, roughings and other large steel products It may be necessary to check dimensions, position or alignment without installing measuring elements in contact with the material.
Dimetix specifically documents the application AE-0214 Slab production, where high-precision laser sensors are used to monitor the dimensions of the slabs during cooling and transport.
In this configuration, two sensors facing each other or positioned on either side of the part can be used to obtain dimensional information. Dimetix indicates the possibility of measuring thickness, length and angular deviation or skew, depending on the arrangement of the sensors.
For this application, Dimetix proposes sensors such as the DPE-10-500, with typical accuracy of ±1 mm and the ability to perform long-distance measurements.
Dimetix also has the case AE-0705 Slab Position Monitoring, Developed for Voestalpine Rail Technology, the application used a DPE-30-500 sensor to detect the presence and position of slabs in an environment with high thermal radiation, smoke, flames, and reflections. After an eight-week testing period, Dimetix documented that the system functioned without detection errors.
Positioning of stops, trolleys and moving parts
Not all applications require direct measurement of the part. In many industrial equipment, it is more practical to measure the position of a stop, carriage, actuator, head or moving element of the machine.
The laser sensor remains in a fixed position and continuously measures the distance to the moving element. This measurement can be used as position feedback and compared to the setpoint programmed in the PLC.
This system can be applied to cutting machines, saws, feeding systems, conveyors, manipulators and special machinery where there is a line of sight between the sensor and the target.
Integration of the laser sensor with PLC and automation
For a machine manufacturer, distance measurement is only one part of the system. The value must be integrated with the machine control system for use in automated sequences, production recipes, format changes, positioning, or alarms.
Dimetix industrial sensors feature various communication interfaces and outputs that allow them to be connected to PLCs, controllers, and data acquisition systems. Depending on the model and architecture chosen, serial communication, SSI, analog output, and various industrial network integration solutions can be used.
| Sensor data | PLC treatment | Possible action |
|---|---|---|
| Absolute distance | Comparison with instructions | Position a cart or stop |
| Position of the piece | Comparison with programmed length | Authorize the cutting cycle |
| Position variation | Tolerance control | To generate alarm or rejection |
| Presence at a certain distance | Window detection | Activate an automatic sequence |
| Continuous measurement | Registration and monitoring | Process control and traceability |
Non-contact measurement in demanding industrial environments
Steelmaking and machining facilities can present challenging conditions for any optical system: dust, vibrations, shiny surfaces, scale, smoke, changes in reflectivity, and high-temperature materials.
For this reason, the selection and placement of the sensor must be considered in relation to the actual application. The working distance, angle of incidence, target surface, temperature at the installation point, and the presence of smoke or particles can all affect the quality of the measurement.
When necessary, the sensor can be installed at a safe distance from the process area, use mechanical guards or auxiliary systems, and measure on a target specifically defined for the application.
Laser sensor, encoder, measuring wheel or laser speedometer?
The most suitable technology depends on which variable the machine actually needs. Dimetix laser distance sensor measures distance and position; It should not be confused with a laser speedometer intended to directly measure the surface speed of a moving belt.
| Need | Standard technology |
|---|---|
| Absolute position of part, carriage or stop | Laser distance sensor |
| Distance to the end of a bar or profile | Laser distance sensor |
| Non-contact measurement at several meters | Laser distance sensor |
| Angular position or revolutions of an axis | Encoder |
| Cumulative length through contact with the material | Encoder + measuring wheel |
| Speed or continuous surface length without contact | Laser speedometer / Doppler technology |
In certain systems, several technologies can be combined. For example, an encoder can control the movement of a drive while a laser sensor provides a absolute reference independent of position.
Advantages of laser sensors for machinery manufacturers
- Non-contact measurement with the moving part or element.
- Possibility of taking measurements at a distance of several meters.
- Absolute position reference.
- Absence of extendable cables or mechanical measuring elements in contact.
- Integration with PLC and automation systems.
- Possibility of installing the sensor protected and away from the process area.
- Applicable to both new machinery and certain retrofit projects.
- Measurement on large parts where a mechanical transducer would be difficult to install.
Dimetix sensor selection for a steel cutting machine or line
The sensor selection must be based on the actual machine conditions. Knowing only the maximum length to be measured is not enough.
To properly size an application, it is necessary to define:
- minimum and maximum measurement distance;
- required accuracy and repeatability;
- speed of movement of the part or the carriage;
- required update frequency;
- type and finish of the target surface;
- temperature and environmental conditions;
- available angle for taking the measurement;
- interface available on the PLC or control system;
- need for continuous measurement or only during certain phases of the cycle.
For long-range and high-precision applications, the following models, among others, can be considered: Dimetrix DPE-10-500, while other models in the D Series may be more suitable when the range, speed, or application characteristics change.
You can view the available range of industrial laser distance sensors or provide us with the machine's specifications so we can study which configuration is most suitable.
Applications in steelmaking, cutting and machining
These solutions can be used in projects related to steel mills, steel service centers, cutting line manufacturers, industrial saw manufacturers, automation integrators, and special machinery builders.
The materials and products that can be found in this type of facility include Sheet metal, coil, strip, bar, tube, profiles, billets, slabs and other long or semi-finished products of steel, stainless steel and aluminum.
GUEMISA can help with sensor selection, defining the working distance, and integrating the measurement with the machine automation system.