Altami Optical Separator project for British American Tobacco Russia is an example of technical (aka machine or computer) vision for industrial application. With cameras and computer algorithms of technical vision, the substandard tobacco (tobacco mixture) is cleaned from undesirable particles determined at visible spectrum. Cleaned tobacco is redirected back to the production of cigarettes. Altami Tobacco Sorter has an integrated interface to ITM Delphi Tobacco Machine and it operates within unified product quality control automation system.
The customer requirements for sorter (aka photo-separator, separator) were to has available selection of sorting recipes by the type of undesirable particles. Also has to display real time information about the detection of garbage during separation.
Also customer required to have automatic diagnosis of the normal flow of separation process, as well as a real-time self-diagnosis of the sorter major components. Altami Tobacco Sorter was also required to feature remote monitoring (via the Internet) for fixing of possible problems by the support staff.
Altami Tobacco Sorter was required to operate in a 24-hour mode, has to has a simple interface and provide minimal efforts for the staff to operate it. The sorter must be integrated with the existing defective cigarette disembowel machinery (ITM Delphi or similar) at the joint start and stop mode, including stops when the separation process fails for any reason.
Undesirable particles include pieces of white pressed filters and paper from cigarettes and aromatic-additive capsules that are present in the tobacco from defective cigarettes, both as whole pieces or very fragmented ones. Aromatic capsules could be of different colours, but they differ from the colour of tobacco.
Note: Tobacco factories produce a certain number (1%-3%) of defective cigarettes during production process. These are fully or partly defective cigarettes that are not allowed to be released to consumer market. Factories have expensive equipment to extract tobacco from defective cigarettes to be returned back to the production (for example, ITM Delphi machine). However, in the process of defective cigarette disembowelling and tobacco extraction, they got undesirable particles that are not permitted in pure conditioned raw tobacco. The BAT factories have a challenge to clean up the extracted tobacco from undesirable particles or get the whole volume of defective cigarettes to be recycled to waste.
The operation of the Altami Tobacco Sorter is based on software algorithms and machine vision hardware for manufacturing processes. Altami Tobacco Sorter (aka photo-separator, separator, sorter) is belonged to equipment for quality check of free-flowing materials.
The described project is the further development of the research work in the field of optical separation of tobacco from undesirable particles that are different types and colour. The difference from the first version of the sorter is the following: in addition to removing of coloured aromatic capsules and their particles, the sorter could remove pieces of cigarette filters and cigarette paper from the tobacco.
Because cigarette filters and cigarette paper are the same colour (white), in terms of the visual spectrum detection method, they represent the same object that needs to be removed. Therefore, the number of fragments to be removed are extremely large as the extracted tobacco from defective cigarettes has a very large density of cigarette paper. This required the high-performance mechanics for real-time removing of cigarette paper and filters.
Mechanical damper, used in the first prototype, was incapable of such work. During next R&D phase, Altami specialists developed a new mechanism for the rapid and efficient removal of detected cigarette filter/paper particles. The project was fulfilled as optical sorter (photo-separator) with pneumatic system for removing undesirable particles from the tobacco coming into control area in the free fall supply.
The tobacco containing undesirable particles comes from ITM Delphi machine by transporter and then is piped into the distribution tank to further feed into sorter control zone as free fall product. At control zone, the high-speed cameras operated by Altami machine vision software are searching for undesirable particles according to several proprietary algorithms. When an undesirable particle (garbage) is detected, its coordinate is determined and a signal is given to open the appropriate pneumatic valve to remove (blowing) the found garbage from tobacco to the bin. The rate at which undesirable particles are detected and removed from tobacco is few milliseconds.
The project is used some R&D results from earlier works:
Strobe LED light source of Altami design with Altami controller;
Developments in machine vision, assessments of video stream from high-speed cameras;
A pneumatic knife (a milled-channel plate for linear removal section).
Development required to implement the project was the following:
High-speed pneumatic valves control controller;
Optimized computer vision algorithms for visual processing and search for a garbage in the tobacco;
Tobacco supply vibrating feeder controller;
New frame base for the sorter.
Altami Tobacco Sorter (photo-separator) has the following specs:
1. Super-fast algorithms for identifying garbage in the tobacco with the response rate of less than 5 ms;
2. The overall performance of tobacco sorting of not worse than 400 kg/hour.
3. Custom developed algorithms for identification of different types of undesirable particles in the tobacco;
4. Technical vision with high-resolution optics for finding garbage sized less than 1 mm. The ability to increase optics resolution according to the client’s specs;
5. High-speed air valves and removal nozzles to delete found garbage;
6. Improved separation unit with 4 mm width of air flow that allows simultaneous removal of undesirable particles of different weight, shape and size, including very small particles;
7. Extra high density of independent air nozzles that allows the following:
Reduce air consumption by the machine;
Minimize the losses of acceptable tobacco threshed leaves with undesirable particles;
Separate a highly contaminated threshed leaves with a high density of undesirable particles;
8. The modular design allows to increase the volume of sorted tobacco upon the factory need;
9. Self-diagnosing of sorter components displays information on a local control monitor;
10. Availability of remote monitoring and troubleshooting by Altami technical support.
11. Examples of undesirable particles being processed:
Rothmans Demi Tube filter shorts,
whole filters or its parts,
capsules of Kent iSwitch or Rothmans Demi Click,
items of cigarette packaging.
Description of Altami Tobacco Sorter Components
Photo of Altami sorter in the BAT factory showing control panel and monitor.
Sorter Schematic Diagram
1. Receiving hopper
2. Vibrating feeder
3. Video camera block containing 3 high-speed 5 mpx video cameras
4. Block-plate of 160 injectors, the size of each injector is less than 5 mm
5. Tobacco separation plate
6. Frame base
7. Acceptable tobacco bin
8. Undesirable particles bin
For additional information on the development of computer vision systems for industrial needs, please contact Altami.