Classifications

• • G—PHYSICS
  • G07—CHECKING-DEVICES
  • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
  • G07C5/00—Registering or indicating the working of vehicles
  • G07C5/002—Analysing tachograph charts

Definitions

• This invention relates to a method and apparatus for reading the recorded graphic data on tachograph charts, for example tachograph discs.
• tachograph charts for example tachograph discs.
• chart By the term “chart” as used in this context it is intended to refer to not only discs but also charts which may be used for a similar purpose in any other suitable shape or form.
• a typical tachograph disc reader comprises a manually operated disc table with cursor, an illuminated magnifying lens for visually inspecting the disc, a small keyboard for the operator to key-in data read from the tachograph disc, and various colour-coded light-emitting diodes which serve as visual aids for the user of the apparatus and to serve as reminders of functions of the apparatus which have been used or are in use.
• An object of the present invention is to provide a method and apparatus for electronically reading the recorded graphic data on tachograph charts offering improvements in relation to the speed and/or accuracy and/or efficiency of reading the data and/or converting same into text and/or numerals, without requiring human visual interpretation of the data as a step in the production of said text and/or numerals, and/or any one or more improvements in relation to other matters discussed or disclosed herein, or generally.
• a method and apparatus for reading the recorded graphic data on a tachograph disc employs electronic scanning apparatus on which a tachograph chart is located, in use.
• the chart is electronically scanned by the scanner so as to produce electronic data representative of the data recorded on the chart.
• the scanner also produces data relating to the disc itself enabling the dimensions and orientation of the disc to be used in computing and analysing the recorded graphic data on the disc.
• the electronic data produced by the scanner is fed to a computer in which the data is processed so as to modify the form of the graphic data so that it can be visually presented in the form of text, charts, graphic display and/or numerals.
• the scanner/computer combination can be linked to a printer in order to generate printed paper copies (hard copies) of numerical and textual data and images corresponding to the graphics recorded on the tachograph disc.
• the printed textual/numerical/graphical data may include a statement of the sequence of activities carried out by the vehicle concerned, such as rest, driving, and other work, with a list of times from and to, for each type of activity, and a summary of the hours and minutes between these times. There may also be provided an overall summary of the activities carried out by the vehicle.
• Other options include a presentation of vehicle speed and distance travelled, together with other corresponding summaries and, on demand, a hard copy of the graphic trace area where an infringement of a regulation has occurred.
• the overall processing of the data from the scanner comprises the preliminary step of processing scanned data relating to the tachograph chart itself, that is to say its shape and dimensions, this data being processed to establish the type and orientation of the chart.
• the chart is scanned to identify its characteristics. These are identified by colour or intensity changes with respect to the background colour or intensity of the support on which the chart is located.
• the data from the scanner is -processed to identify sufficient edge points on the disc, whereby its centre can be calculated. For example, four edge points may be established, these being obtained by identifying the topmost and bottommost black/white transitions and the leftmost and rightmost black/white transmissions.
• analysis of same by the computer comprises identifying the graphic trace by identifying colour or intensity changes on the disc with respect to the basic disc colour/intensity. It is preferred to analyse on the basis of colour ie the black of the trace and printed matter, and the white of the disc background. All other colours are masked out.
• the data analysis proceeds by dividing the tachograph chart data into data relating to the concentric bands on the chart, and this data is then transformed by the computer so as to correspond to a linear representation of these concentric bands.
• This linear representation of the disc is used as a basis for the interpretation of the distance and activity and speed data recorded on the chart.
• the graphic data from the tachograph disc itself can be reliably computed to generate text, graphical display, and/or numerical data which is readily understood and read by even a relatively unskilled person.
• the apparatus consists of a document scanner coupled to a personal computer incorporating a programme to analyse the scanned tachograph image.
• a document scanner is currently preferred as the scanning apparatus, it is envisaged that alternative electronic scanning means such as an electronic camera may be substituted.
• the results generated provide details of driver and vehicle activity, distances covered and vehicle speeds, together with any other trace information recorded by the tachograph on the tachograph disc surface.
• This data is printed in the form of text, graphs and numerals by means of a standard printer, for example a laser printer.
• the system operates in the following manner.
• the tachograph chart is first placed on the document scanner. This is a standard document scanner. It scans the tachograph chart and produces a resultant image in the form of electronic data which is fed to the computer and stored therein.
• the scanned image is analysed in the computer memory, rather than on disc, for rapidity of processing.
• a facility for storing the image on disc is provided, principally to obviate the need for re-scanning the disc later, if need should arise.
• the format of the image data is determined by the manufacturer of the scanner.
• the data from the scanner, if storage of the image is required, is stored in an industry standard format, for example that known as PYX.
• the image data is then converted into a different format, known as bitmap or BMP which is more easily interpreted by the computer programme.
• the system operator selects an appropriate menu option from the visual display unit of the computer of the system, in the usual way, and activates the computer to commence data processing.
• the computer first processes data relating to the chart or disc itself in order to establish the disc size, disc type, disc centre and disc orientation. These factors are needed in order to properly relate the graphic data represented by the tachograph trace.
• the geometrical techniques adopted by the computer in analysing the data relating to the tachograph disc itself are as follows.
• the disc centre is established by taking two diametral lines based on the topmost/bottommost/leftmost/rightmost edge points located, and by finding their point of intersection.
• the diameters also provide, of course, a measure of the disc radius.
• the characteristically shaped central cutout on all presently available tachograph discs can be read by the system from the image data produced by the scanner.
• the technique for this is as follows.
• disc 10 comprises a central cut ⁇ out 12 which is generally pear-shaped. Such a shape is provided on.Lucas-Kienzle discs. Other manufacturers' discs have alternative orientation means such as a central circular aperture and two marker holes. In the case of the disc 10, the orientation of the disc is identified as follows.
• the circumference of a circle with a radius slightly larger than that of the circular part of the pear- shaped opening is searched for black sections ie sections which are not white, the dominant colour of the disc.
• the largest black section found is deduced to be the open-ended part of the pear. A point halfway between the ends of this section is deduced, and the 12 o'clock position is therefore on the radius line that runs from the disc centre through this point.
• the orientation of the disc is established by use of mechanical means, such as a lug, provided on the scanner and cooperating mechanically with the disc to physically ensure that it is mounted in a predetermined orientation for scanning purposes.
• mechanical means such as a lug
• the analysis of the data by the computer can then proceed by a series of steps, as follows.
• the data from the disc is divided into data relating to concentric bands of defined radii.
• the data relating to each band is transformed so as to represent the band in linear rather than circular form. This is achieved by taking each radius line from the centre of the disc and treating it as a pixel-wide slice from a rectangle.
• the computer has produced a linear representation of the ' graphic data recorded on the tachograph disc. This linear representation is then interpreted in accordance with the following procedure.
• the image of the graphic trace that is obtained from the scanner is not necessarily complete, and may contain a large amount of extraneous information, this usually taking the form of islands of black, which is a result of the effect of printing onto sensitive paper, and scratches caused by disc handling. Therefore, the following process is employed to identify the graphic trace and to eliminate matter which is to be ignored.
• each band of black in that slice is given a weighting, initially zero.
• the weighting indicates how long the particular line has been followed, and determines whether the line is to be followed or not, as indicated below.
• the band with the highest weighting is considered to be the trace line unless there are bands with equal weightings, in which case the widest is considered to be the trace.
• Overlap of bands is handled as follows. Where bands in the preceding slice split, the weighting of each band in the new slice is given the same weighting ie the previous weighting plus one. Where bands in the preceding slice merge, the weighting of the band in the new slice is given the same weighting as one and only one of the preceding bands plus 1. Bands that are not considered significant in accordance with these rules are discarded.
• each such passage corresponds to 5 kilometres of distance travelled for every two peaks of the waveform, and hence the vehicle distance travelled can be calculated.
• an analysis of the data is made with respect to the thickness of the trace line, that is to say whether the trace line is thick or thin, and also of its distance from the disc centre.
• This analysis establishes periods of vehicle movement and periods when the vehicle was stationery.
• the analysis shows the 10 position of the activity selection switch of the tachograph instrument itself.
• the tachograph activity switch is a driver-operated control which is manipulated by the driver to indicate to the tachograph the type of activity undertaken by the vehicle at any given time.
• the activity trace 16 indicates the activity type by means of the radial position of the trace, working outwards from the centre of the disc.
• the innermost position indicated at 16A indicates rest, there is shown at 16B "other work" ie a subsequent inactive period, and at 16C is shown driving activity.
• the electronic data produced from the graphic image is checked for the passage of the trace line through the disc radius corresponding to a menu-selectable speed. Where the trace line passes through the radius, the trace around the speed violation is checked in order to see if this is the start or the end of an over-limit event. The starts and ends of these events are accumulated to produce a speeding offence summary.
• the data produced as described above is passed to a visual display unit and/or a printer for study by the operator.
• the output from the computer can alternatively be passed, via a serial data link, for use in the same manner and in the same format as that currently produced by manual tachograph readers.
• the computer output can be plugged directly into higher level vehicle fleet management systems and, for example, the data can also be used in association with the UK Department of Transport's Hours Law software package. This is a user-selectable option, and the data can be formatted to correspond to that of known manual readers eg that known as Veeder Root.
• the data derived from tachograph charts and disc is stored in the computer and can be accessed, sorted and displayed in accordance with a variety of criteria.
• the processing of these can be on an every disc basis rather than merely on the basis of occasional analysis of discs from time to time.
• Such an approach enables, for example, unauthorised use of vehicles to be monitored, and the total recorded tachodisc milage can be compared to the vehicle odometer.
• the analysis and identification of the graphic trace on the tachograph chart or disc depends, amongst other things, upon an ability of the computer to identify and distinguish the trace from standard printing on the disc, irregular black or other colour marks on it, and from scratches etc. Such distinguishing of the trace is achieved, as described, by steps in the analysis programme whereby certain data transmitted by the scanner is ignored.
• the location of the trace on the disc is known, whereby data from elsewhere on the disc can be ignored.
• the location of the printed matter on the disc is also known and instructions can be included in the programme to ignore (so far as identification of the graphic traces is concerned) such printed matter.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Time Recorders, Dirve Recorders, Access Control (AREA)
• Recording Measured Values (AREA)
• Optical Recording Or Reproduction (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

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• 1991
  • 1991-10-16 GB GB919121970A patent/GB9121970D0/en active Pending
• 1992
  • 1992-10-12 EP EP92921310A patent/EP0608297B1/de not_active Revoked
  • 1992-10-12 WO PCT/GB1992/001857 patent/WO1993008543A1/en not_active Application Discontinuation
  • 1992-10-12 ES ES92921310T patent/ES2131076T3/es not_active Expired - Lifetime
  • 1992-10-12 AU AU26903/92A patent/AU2690392A/en not_active Abandoned
  • 1992-10-12 AT AT92921310T patent/ATE180078T1/de active
  • 1992-10-12 GB GB9407449A patent/GB2275336B/en not_active Expired - Fee Related
  • 1992-10-12 DE DE69229178T patent/DE69229178T2/de not_active Revoked

Non-Patent Citations (1)

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