DE4402779C2 - Gas station monitoring system - Google Patents

Description

The invention relates to a gas station observation system with at least one video camera.

Such observation or surveillance systems have so far been for the following Applications known:

• - Building and access monitoring
• - Process control technology and remote system monitoring (e.g. pipeline pump station)
• - Conveying and storage technology
• - petrol station monitoring
• - traffic monitoring
• - Identification device (e.g. barcode reader)
• - Vehicle technology (e.g. automatic field-by-mirror darkening when used in place a conventional rearview mirror)
• - motion and position sensors.

In the process monitoring, the following result in particular Possible uses:

• - Detection of liquid, smoke and steam leakage (image change)
• - Evaluation of the position of levers and sliders (position information and Position monitoring)
• - container inspection (replacement of sight glasses)
• - Detection of quantities that are difficult or impossible to measure with conventional sensors (e.g. color changes, shape changes, texture changes [e.g. liquid surface smooth or boiling])
• - Possibility of "video tours" (remote control without direct system access).

Within the scope of applications in conveyor and storage technology, the the aforementioned points are also of some importance. In addition, in particular the following possible uses are mentioned:

• - Image transmission from a storage and retrieval machine to the control center
• - Dangerous goods warehouse monitoring (leaked liquid, defective containers)
• - Contour control (instead of using several light barriers
• - Pallet type recognition and pallet condition control
• - Automation of pallet loading and unloading (storage detection of boxes and Containers)
• - Identification (barcode reader)
• - Position detection of goods to be conveyed on conveyor lines  
• - inventory control, counting (inventory support)
• - Control and optimization of loading.

State of the art in video surveillance of petrol stations are CCD cameras, which Convert image information into analog signals and permanently use coaxial cables transfer. The analog image signals from these cameras are at the end of the Transmission path through a (possibly special long-term) video recorder commercially available video tapes recorded. Depending on the frame rate Recording times from 24 hours up to several hundred hours possible.

The petrol station and cash desk are filmed and recorded as a flat rate, regardless of whether there are people in the cash desk or whether they are refueling or not. To do that To reduce the amount of magnetic tape material required are so-called Time / lapse recorder used. These draw the signals from several cameras in the Time-division multiplexing in succession with an adjustable frequency, typically approx. 1 to 2 Frames per second. This requires a so-called video multiplexer, which has several incoming ones Switches video signals to an output one after the other at fixed time intervals. In The multiplexer function can already be integrated in special video recorders.

As an alternative to this process, Grundig offers an image recording device that digitizes images on a hard drive. Only the images are saved, that differ from the previous picture, d. H. longer passages in which there is nothing changes are not recorded. In addition, the image memory is permanently automatic overwritten, so in the event of an event "customer did not pay" the Image information can be marked as relevant (manually by personnel).

In a television monitoring system according to DE 41 10 649 A1, in which movements in images recorded by a television camera are determined by a recognized movement of the relevant part of the image with the patterns of a variety of Pattern storage containing patterns compared and if they match Pattern the same for display on a remote site monitor on a Transmission line transmitted. In this way, the monitor monitoring Person on the use of a certain object in the subject to be monitored Object quickly and clearly.

In the document DE 41 38 538 A1 a video surveillance system is described, which suitable for cost-effective remote monitoring. The main components of the system are data-reducing coder and a corresponding decoder, each via control units are connected to a long-distance line. The control units of the encoders exchange with the Control unit of the decoder via the transmission line data.  

The control units of the encoders contain controllable changeover switches, the position of which depends on which of the system's cameras is used for the current monitoring shall be. Your pictures are displayed on a monitor. Switching to one other camera is made with a control computer.

Such "intelligent video cameras" are basically for use with a Petrol station monitoring is suitable, but the cameras are activated complicated way from a control computer and / or depending on the image content.

As from the essay "EPSI: A fieldbus prevails" in the section "Measure-Control- Rules "of the magazine Markt & Technik No. 42 of October 15, 1993 can be found Tank data acquisition, transmission and processing systems known to u. a. also the dispensers are connected.

The invention had for its object to provide a gas station monitoring system, that uses the previously known camera technology and can be controlled specifically for a petrol station.

According to the invention, the object is in accordance with the features of the first claim solved.

In the subclaims, expedient refinements of the invention are specified.

The focus is on a digital video camera that is bus-compatible at low cost producible and because of the integrated evaluation electronics as an "intelligent" camera is designated. The camera can go beyond the usual camera functions Recognize task-specific relevant scene content or scene changes. The relevant images can optionally be compressed in the camera (data reduction) and at Transfer demand serially to an electronic control center via an image signal line will. The term control center only means a facility in which the transmitted image information electronically recorded or for a viewer can be made visible. Within an overall system can therefore there are several "control centers". No special video is required for image transmission Coaxial cabling required, but because of the compressed serial image transmission a possibly existing simple line infrastructure, such as a Telephone cable or a 2-wire line can be used. Multiple smart cameras can also be used simultaneously with other fieldbus devices on one wiring harness be connected. Depending on the image quality requirement, standard Video lenses or preferably inexpensive fix focus plastic lenses are used will.

The opening angle of the camera is typically between 30 and 80 °.

The invention will be explained in more detail using an exemplary embodiment.

1. Service station monitoring 1.1. aims

• - Early (re) detection, prevention or tracking of tank fraud and gasoline theft,
• - Registration of vehicle type, number plate and people during the refueling process,
• - more efficient, more efficient and cheaper solution than with conventional video surveillance systems.

1.2. Motivation and background

• - New technical developments (low-cost CMOS image sensors, image compression techniques), the intelligent, bus-compatible, digital cameras enable (icam),
• - upcoming introduction of standardized, digital tank data systems,
• - increasing tank theft rates,
• - Initiatives by oil companies to create new, gas station-wide Overall surveillance concepts.

1.3. description

Digital image acquisition and evaluation system (video surveillance system), Particularly suitable for petrol stations with digital tank data systems, consisting of:

• - Several "intelligent" video cameras, which are able to camera internally
  • - Digitize image signals (e.g. in 256 × 256 pixels with 256 gray levels each,
  • - save image data (e.g. up to 25 images),
  • - compressing image data, ie performing data reduction (e.g. factor 3-5), transmitting compressed image data via digital interfaces / transmission media,
  • - (Optional) analyze image data for changes, shape (e.g. detection of simple rectangular structures, straight edges) and movement.
• - (Image) data transmission media (e.g. serial, line-bound via 2-wire lines such as Fieldbuses or wireless via IR links, RF or HF radio links), preferably already existing line or data transmission infrastructure;
• - Image data storage and output unit (e.g. PC with hard disk and graphic printer) for long-term storage or documentation of alarm images and related Tank data.

Key points of the application of such a video surveillance system in the Petrol station areas are on the one hand the direct physical coupling and on the other hand the logical / information-related integration of video surveillance into the (possibly also existing) digital tank data system.

Explanation: For control, data acquisition and data transfer in the tank area (i.e. between the petrol pump, POS cash register, large tank, car wash ...) standardized, digital, serial fieldbus systems will be used in the future. In the closer Selection and in some cases already in test use are on the DIN measurement bus based "European Petrol Station Interface", EPSI, as well as the "Local Operating Network", LON, from Echelon.

Physical coupling

So far, video surveillance in the petrol station area was logically and physically separate system, d. H. with its own cabling, data processing and Storage infrastructure. Bus-compatible, image-compressing connected to the tank data system Cameras can use this digital data transmission infrastructure to receive control commands via it (e.g. for image acquisition or for Image transmission) and image data for central storage (e.g. to a Image storage PC in the cash desk). This eliminates the previously required, own (expensive) Coaxial cabling for analog image transmission. Remote supply is also conceivable (Power supply) of the cameras directly via the data lines and thus another Simplification of installation and cabling reduction.

Logical coupling

So far, the video surveillance system "did not know" or "learned" about the relevant ones Conditions and events such as "refueling begins", "refueling finished" and "payment made". However, this information is explicitly and already electronically in the tank data system processable before. It can be used to trigger a targeted, event-controlled video to realize and thus only capture relevant scenes. So (and through digital bid compression), significantly less storage space is required for image storage compared to general, periodic image acquisition. In addition, the compressed Image data in the event of fraud automatically together with the associated tank information (Date, time, dispenser number, type of fuel, quantity of liter, price,...) Digitally saved will.

Image evaluation

A third key aspect in this application is the ability of the camera to do so internally To be able to perform image evaluation function and thus relevant scene changes,  possibly also simple shapes and movements, to be able to be recognized automatically in the field of vision (e.g. the roughly rectangular outline of a vehicle or the movement of the vehicle rear or leading edge when driving away from the tap). Such a video surveillance system could hereby immediately automatically trigger an alarm if after the event "Refuel finishes "a vehicle moves away from the pump before" payment is made " is signaled.

1.4 Application scenario

Possible process: e.g. B. First image is captured when refueling begins (gasoline flows), second image is captured when the refueling process is finished (tap again mounted). Both images initially remain stored locally in the camera, so they are not yet transferred to the "control center" (e.g. image storage PC).

If the payment process for the petrol pump in question is "successfully" completed, the locally cached images in the camera (s) are immediately deleted. Is the Payment process open and fraud detected (either manually or automatically Capturing the vehicle movement when driving away), the local images of the Transfer camera (s) to the central PC hard disk memory and there together with the associated tank information filed. In the case of automatic vehicle motion detection the staff is immediately alerted by an alarm and the relevant Images and information output. If necessary, the system is with a barrier or other Device coupled that prevents the vehicle from moving away in the event of an alarm.

1.5 Improvements over the state of the art

By coupling to the tank data bus and controlling the image recordings above only relevant scenes are recorded, e.g. B. from the signal "petrol filled "of the tank data system (see also 1.4).

In the camera, several images can initially be stored locally until It has been clarified whether the recorded scenes are permanently in need of storage. Not Images to be documented can immediately be deleted in the camera and "forgotten" if a refueling operation has been properly paid for.

This means that the vast majority of the images captured initially do not even have to transferred and therefore not saved centrally.

This is also a legally simplifying aspect with regard to data protection general long-term video recorder recordings.

The bus-compatible camera uses the existing line infrastructure of the digital tank data bus. Multiple cameras can be on a wiring harness, along with others Bus devices (petrol pumps) must be connected. In contrast, analog video cameras require each with its own coaxial cable for image transmission. This results in an ent  talking material cost reduction, but especially a significant simplification of installation, especially when retrofitting.

The intelligent digital camera can also be used as part of digital tank data systems existing data processing, control and storage devices (increasingly PC-based) share, does not require your own IT infrastructure and video recording devices.

1.6 Further possible applications

• - Video surveillance in plant and process control technology
• - Video surveillance in conveyor and warehouse technology

Analogous to the petrol station application, there are advantages from the use existing digital data transmission, data processing, storage and Visualization infrastructure of process control systems or conveyor control rooms.

On the other hand, the intelligent camera can not only deliver images to an operator perform new, automatic monitoring and measuring functions.

Claims (20)

1. petrol station observation system with at least one video camera, which is connected via an image signal line to an electronic control center, which includes an electronic device for recording and / or visualizing image signals, wherein

• the video camera is designed as a digital camera,
• the video camera comprises an image memory which can store a plurality of images, preferably 2-50 images, which are periodically deleted,
• - The video camera has evaluation electronics, by means of which, prior to the feeding of image data into the image signal line, either data compression and / or an examination of the captured image contents for the presence of significant details takes place on the basis of stored decision criteria and
• - The acquisition, deletion and transmission of the image data in or from the video camera takes place as a function of tank status signals which are generated by a tank data system present in the gas station.

2. observation system according to claim 1, characterized, that the image memory provides a grid of at least 256 × 256 pixels. 3. observation system according to one of claims 1 or 2, characterized, that the image memory has a large number of detectable gray levels, preferably at least 256 grayscale. 4. Observation system according to one of claims 1 to 3, characterized, that the evaluation electronics is programmed in such a way that it is used for image data compression data reduction at least by a factor of 3-5. 5. observation system according to one of claims 1 to 4, characterized,  that the evaluation electronics is programmed in such a way that the feeding of the image data into specified longer intervals (preferably several seconds to a few minutes) he follows. 6. observation system according to one of claims 1 to 5, characterized, that the evaluation electronics is programmed in such a way that the feeding of the image data into Depends on the discovery of significant details. 7. Observation system according to one of claims 1 to 6, characterized, that the evaluation electronics is programmed in such a way that the captured image data is temporal Changes in image details and / or simple geometric structures to be analyzed. 8. observation system according to one of claims 1 to 7, characterized, that in the control center for recording the transmitted digital signals, a computer system, preferably in the form of a PC with magnetic disk storage and graphics capable Printer, is provided. 9. Observation system according to one of claims 1 to 8, characterized, that the camera has a data input via which signals can be input that the Influence evaluation electronics. 10. Observation system according to claim 9, characterized, that requirements for image transmission can be entered manually via the data input are. 11. Observation system according to claim 9 or 10, characterized, that the data input with individual units of a technical system for the transmission of Status displays of the individual units is connected.   12. Observation system according to one of claims 1 to 11, characterized, that the evaluation electronics is programmed such that, depending on the type of ascertained significant detail, in addition to an image transmission, a data output, preferably in the form of an alarm message. 13. observation system according to claim 11 to 12, characterized, that the technical system is a filling station accounting system. 14. Observation system according to one of claims 1 to 13, characterized, that the picture signal line is a 2-wire line. 15. Observation system according to one of claims 1 to 14, characterized, that the image signal line is designed as a telephone cable. 16. Observation system according to one of claims 1 to 15, characterized, that the image signal line and the electrical used to power the camera Line connection are physically identical. 17. Observation system according to one of claims 1 to 16, characterized, that the image signal line is a digital serial fieldbus. 18. Observation system according to one of claims 1 to 17, characterized, that at least part of the image signal line in the form of an infrared transmission path or as RF or HF radio link is formed. 19. Observation system according to one of claims 9 to 18, characterized, that the data input of the camera can be controlled via the image signal line (identity of Data input line and image signal line).   20. Observation system according to one of claims 12 to 19, characterized, that the image signal line is also used to transmit the additional data outputs, in particular of alarm messages, is provided.