Measuring system for the control of large size products
Large engineering companies often face challenges on controlling the geometry of large forged, molded or welded structures.
Control objectives can be different - from the input and output control at the exchange of products between counterparties to the auxiliary control within the manufacturing process in order to optimize subsequent machining.
Our company offers measuring systems that can be divided into the following groups: system based on laser trackers, systems based on laser radars, complex automated and robotic systems based on the above-mentioned basic measuring instruments with additional primary sensors such as laser scanners, stereoscopy systems, computer (machine) vision systems, interferometers.
Solutions based on laser trackers
Tracker-based laser coordinate measurement system consists of a measuring unit on the mobile telescopic tripod and reflection target. Principle of continuous tracking of the target location in space by stationary unit serves as the basis of its operation.
Reflector is a set of metallic mirrors, pressed into a metal sphere. Spheres have a standard diameter of 1.5 and 0.5 inches. Installation of reflectors in reference points and determination of their coordinates is carried out during the geometry measurement. Reflectors can be simply propped against the controlled surface or mounted on special supports and probes, allowing to control hidden surfaces of the objects.
Measuring unit comprises an optical system, servo drives, goniometric devices, blocks of distance meters (interferometer and the absolute distance meter) and has two perpendicular rotation axes. Rotation around the axes is carried out by means servo drives, each axis is equipped with angular encoder. Servo drives allow to direct a distance meter laser beam to a given point and track the position of the reflector. Built-in weather station allows to adjust the meter reading depending on the parameters of the environment in order to achieve maximum accuracy.
Due to the fact that the target must be within the field of view of the measuring unit during measurement, measuring unit is often have to be moved when controlling oversized and complex objects. A set of 4-5 statically mounted targets is used for its referencing in space.
The following measurement modes are possible:
periodic survey of all the visible reflectors (when installing and controlling large-sized products) with the deviations from the theoretical (1-5 seconds per point);
evaluation mode for microvibrations and instability of environmental conditions for static points.
reference points position control of the item during product installation. Continuous updating of the coordinate values of targets and their comparison with the specified values occurs in this mode. When coordinates of points fall within the tolerance zone, the tracker emit a sound signal, indicating the precise alignment of parts.
referencing of the measuring unit on basic points, referencing to the standstill.
Tracker is a set of mirrors, optical elements, image sensors, servo drives. Each of them has a mathematical model (several tens of parameters), which is further refined while the positional relationship of elements changes during operation. The tracker kit includes a calibration software, a set of reference objects which are used for calibration.
- performing high precision work to control the geometric parameters of complex structures;
- position control of parts in the assembly of products;
- calibration of machine tools and measuring machines (in interferometer mode);
- micro motions control of machine elements;
- periodic control (without operator intervention) of bearing structures geometry at long static load;
- process control;
- periodic calibration of complex equipment and stocks;
Built-in camera allows less interference in the work of the tracker. Accelerates the process of pointing to the reflectors and generally reduces the time for measurement. The operator can visually observe the measured area on the computer screen, using a special connected video camera, eliminating the measurement errors on the incorrectly selected point and allowing remote measurements.
The IntelliprobeT device, manufactured by Automated Precision allows the operator to measure the hidden points with high accuracy (100 microns) at a distance of more than 25 meters. The hidden points can be measured using the IntelliprobeT device, equipped with 50 and 100 mm probes. Additional probes up to 700 mm can be installed. Laser scanner, which is capable of obtaining 3D data about surface profile of objects within a radius of more than 25 meters and has a scan speed up to 9000 points per second can be installed instead of the probe. Operating scanning band 175 mm + 25 mm.
- Working area: from 0 m to 110 m (sphere diameter)
- Working area along the horizon: +/-270°
- Vertical working area: from 75° to - 50°
- Overall dimensions: up to 300x600 mm
- Head weight: up to 20 kg
Operating temperature range: from -15° to +50 °C
Humidity: from 0 to 95% without condensation
Accuracy characteristics of model trackers
- Angular accuracy characteristics
- Angular accuracy: 10 μm + 2 μm/m
- Maximum angular velocity: 180°/sec
- Linear accuracy characteristics in interferometer mode
- Maximum measurement rate: up to 10000 points/sec
- Resolution: 0.2 µm
- Accuracy: 2 µm + 0.4 µm/m
- Maximum radial velocity: 4 m/sec
- Linear accuracy characteristics in phase distance meter mode
- Maximum measurement rate: up to 10000 points/sec
- Resolution: 0.5 µm
- Accuracy: 8 µm + 0.4 µm/m
- Maximum radial velocity: unlimited
Solutions based on laser radars
Laser radar is a complete high-precision control and measuring machine enabling automatic scanning of surfaces arranged around measuring head in a radius of 60 meters with a volumetric accuracy up to 0.1 mm (at maximum range).
The measuring unit of the radar consists of a laser distance meter, beam deflection system and servo drives with encoders. Deflection system can send the distance meter beam to any point in space around the radar. Simultaneous measurement of the distance to the point with the current values of the angle and azimuth of the beam allow referencing the point to the coordinate system.
The principle of measuring the distance on the frequency shift between the emitted and the received frequency modulated (200 GHz) infrared laser signal underlies the applied distance meter.
Please note that the above set of equipment is a unique mobile coordinate measuring system, which can be placed directly in the place of measured objects, it doesn't require the construction or use of a separate room, operates at temperatures of 5-40 C°, allows scanning any surface without contact.
This equipment allows you to scan both separate elements (mounted spheres, holes, special grades), as well as unspecified surface elements with assignable increment size in manual and automatic modes (controlled by the built-in video camera and in accordance pre-written procedures).
- non-contact measurement system: the lack of reference points, reflectors, probes;
- big operating range up to 60 m
- the use of mirrors for measuring objects on the reverse side;
- scanning with specified increment size;
- complete metrological system;
- combining multiple radars;
- High scanning speed: up to 1000 points/sec;
- Compatible with standard CAD packages;
- Automation: measurement using pre-written scripts and automatic creation of reports;
- Key benefits
- High accuracy;
- Scanning hot objects (up to 1500 degrees)
- Scanning oversized objects without any additional accessories;
- Minimum preparation for measurements;
Scope of application
- continuous control during assembly of large objects (aviation, shipbuilding, construction);
- control and re-engineering of ship propellers;
- shrinkage control of forgings;
- Scanning speed: up to 1000 points/sec;
- The depth of the working area: 60 m;
- Azimuth range: 360°;
- Range in elevation; +45°;
- Volumetric accuracy:
- 10 µm at a distance of 1 m;
- 102 µm at a distance of 10 m;
- 240 µm at a distance of 60 m;
When solving non-standard problems that require the use of multiple measurement tools with the consolidation of their data, as well as combining the complex measurement system with industrial control systems, our company can offer a full range of engineering services to build turnkey systems.