Tachograph

Last updated

Analogue tachograph Tachograph.jpg
Analogue tachograph
Tachograph chart Tachoscheibe.jpg
Tachograph chart

A tachograph is a device fitted to a vehicle that automatically records its speed and distance, together with the driver's activity selected from a choice of modes. The drive mode is activated automatically when the vehicle is in motion, and modern tachograph heads usually default to the other work mode upon coming to rest. The rest and availability modes can be manually selected by the driver whilst stationary.

Contents

A tachograph system comprises a sender unit mounted to the vehicle gearbox, the tachograph head and a recording medium. Tachograph heads are of either analogue or digital types. All relevant vehicles manufactured in the EU since 1 May 2006 must be fitted with digital tachograph heads. The recording medium for analogue heads are wax coated paper discs, and for digital heads there are two recording mediums: internal memory (which can be read out with one of a variety of download devices into a so-called .ddd file) and digital driver cards containing a microchip with flash memory. Digital driver cards store data in a format that can later also be read out as a .ddd file. These files - both those read from internal memory with a download device, and those read from the driver cards - can be imported into tachograph analysis/archival software.

Drivers and their employers are legally required to accurately record their activities, retain the records (files from internal memory and from driver cards must both be retained) and produce them on demand to transport authorities who are in charge of enforcing regulations governing drivers' working hours.

They are also used in the maritime world, for example through the Central Commission for Navigation on the Rhine.

Origins

The tachograph was originally introduced for the railways so that companies could better document irregularities. The inventor was Max Maria von Weber, a civil servant, engineer and author. The Daniel Tachometer has been known in the railway industry since 1844. [1] The Hasler Event recorder was introduced in the 1920s.

Regulations

For reasons of public safety, many jurisdictions have limits on the working hours of drivers of certain vehicles, such as buses and trucks. A tachograph can be used to monitor this and ensure that appropriate breaks are taken.

In Germany (historical)

The Verkehrs-Sicherungs-Gesetz (German Traffic Safety Law) of 19 December 1952, made tachographs mandatory in Germany for all commercial vehicles weighing over 7.5 tonnes. Since 23 March and 23 December 1953, all new commercial vehicles and buses must be equipped with the device per law Straßenverkehrs-Zulassungs-Ordnung § 57a.

Tachographs are mandatory for vehicles allowed to carry a total weight of over 3.5 tonnes and vehicles built to carry at least 9 passengers, if the vehicle is used for commercial purposes. They are used to review the driving and rest time of drivers during reviews by traffic standards organizations or accident investigation. A driver must carry the tachograph records with him for all days of the current week and the last day of the previous week that he drove. Companies must keep the records for 1 year. In Germany, § 16 of the work time regulations lengthens this time to 2 years if the records will be used as proof of work time.

In the EU

EEC regulation 3821/85 [2] from 20 December 1985 made tachographs mandatory throughout the EEC as of 29 September 1986. (Regulation 1463/70 amended by regulation 2828/77 made tachographs mandatory by 1 July 1979, reference to these regulations can be found in regulation 3821/85).

A "European arrangement in regard to the work of driving personnel engaged in international traffic" (AETR, from French "Accord Européen sur les Transports Routiers") became effective on 31 July 1985.

Regulation 561/2006/EC of the European Union adopted on 11 April 2007 [3] specified the driving and rest times of professional drivers. These time periods can be checked by the employers, police and other authorities with the help of the tachograph.

Analogue tachographs

Most tachographs produced prior to 1 May 2006 were of the analogue type. Later analogue tachograph head models are of a modular design, enabling the head to fit into a standard DIN slot in the vehicle dashboard. This would enable a relatively easy upgrade to the forthcoming digital models, which were manufactured to the same physical dimensions.

The analogue tachograph head uses styli to trace lines on a wax coated paper disc that rotates throughout the day, where one rotation encompasses a 24-hour period. If the disc is left in the head over 24 hours, a second trace will be written onto the first, and so on until the disc is removed. It is an infringement of EU Regulation 561/2006 to use a disc for a period longer than it is designed for. Multiple overlapping traces may still be deciphered in the speed and distance fields, but it is far more difficult for the activity field where one trace can easily be obliterated by another. Analogue tachograph heads provide no indication to the driver of the need to change the disc.

Analogue data is retrieved visually, and can be assisted by manual analysis tools. Analogue discs can also be electronically scanned and analysed by computer, although this analogue to digital conversion process still requires human expert interpretation for best results, due to imperfections in the source disc such as dirt and scratch marks in the wax surface that can be incorrectly read as trace marks.

The analogue chart (EU)

The analogue chart must be EU type approved. The country of type approval can be found on the rear of the chart, i.e. a mark of E11 would indicate the chart to have been approved in the UK for use in the EU. The chart is manufactured out of heavyweight paper with a black printed face that is thinly coated with a white wax, upon which is printed a number of features. The surface can be scratched or rubbed to reveal the black paper underneath. This enables the traces to be made without the use of ink. The chart features a pear-shaped aperture in the centre, ensuring it is perfectly aligned upon insertion into the tachograph head. There is no facility to prevent it being inserted back to front, where the styli would be prevented from making contact with the wax surface.

The centrefield is used by the driver to store certain handwritten information. This includes the drivers name, the date(s) the disc refers to, the start and end odometer readings and the registration mark of the vehicle.

Three traces are made in the wax surface by the head. These traces are either made by three separate styli or a single multipurpose stylus.

The trace closest to the centrefield is the distance trace. The stylus moves up and down with distance travelled, producing a zig-zag pattern, often referred to as a 'V' trace. A complete deflection is created every 5 kilometres, and therefore each completed 'V' represents 10 kilometres travelled. By counting the zig-zags, the total distance travelled can be calculated and compared against the stated odometer readings in the centrefield. By comparing the end position of the trace for a particular day against the start position for the following day, it can be seen if the vehicle has moved in the intermediate period.

The trace in the central area is the mode trace. The driver's activity is displayed in this area, and is always displayed as either drive, other work, availability or rest. Earlier tachograph heads displayed the mode as a thin line in one of four concentric tracks within the activity band. These heads are known as manual heads as the activity was manually selected using the mode switch. Automatic heads succeeded manual heads, and differ from them in two main areas. Firstly, the automatic head will always display the drive mode when the vehicle is in motion, regardless of the setting of the mode switch. For this reason, the drive mode is no longer available to be selected by the mode switch. Secondly, the activity is displayed on the chart as a sequence of block traces of differing thickness. The rest mode appears as a thin line, availability as a slightly thicker line, other work as slightly thicker again and the drive trace being the thickest.

The trace closest to the outer edge is the speed trace. The disc is preprinted with a speed scale and the stylus produces a mark corresponding with the speed of the vehicle at any given time. It is important that the maximum speed (Vmax) specification of the chart matches that of the tachograph head for the speed to be correctly recorded. It can be expected that a high speed trace will correlate with a tightly spaced zig-zag pattern within the distance trace.

The disc is preprinted with a 24-hour scale that completes the outer circumference.

The rear face of the chart is printed with a grid that enables the driver to make handwritten additions or amendments to the information on the front.

Its use in accident investigation

Apart from enforcing regulations, tachographs are often used in Germany to investigate and punish speeding. This practice was approved by the German high regional court in the 1990s. Also, after an accident, the discs are often examined with a microscope to discover the events that took place at a collision site.

Tampering

Tachographs can be tampered with in various ways, such as slightly twisting the marker, blocking the path of the arm with a piece of rubber or foam, short-circuiting the unit for short periods, intentionally preventing the detection of gear movement with a magnet, or interrupting the (older analogue) tachograph's power supply with a blown fuse to stop operation completely thus recording no information whatsoever. There is also "forgetting to insert" the chart when beginning duty. Unauthorized changing of the discs (and then discarding one of the two, so that some activities are "forgotten") is well known throughout Europe. "Ghosting" is another common trick when false driver information is entered onto a second chart to give the appearance that there is a second driver present in the cab for long-distance runs that cannot be completed within a single driver's daily driving period.

Digital tachographs

Introduction of the digital tachograph in the EU

Digital tachographs make tampering much more difficult by sending signals in an encrypted manner. EU regulation 1360/2002 makes digital tachographs mandatory for all vehicles described in the above section Regulations and manufactured after 1 August 2005. Digital tachographs have been required as of 1 May 2006 for all new vehicles for which EWG regulation VO(EWG)3820/85 applies, as was published in the official newsletter of the European Union L102 from 11 April 2006.

Digital tachographs have been implemented in Mexico since 1994, but this is not a federal regulation. The last implementations developed in Mexico have GPS capabilities such as mapping, altitude and location-activated video triggering.

See also

Further reading

German Book about the invention of the tachograph and the history of the main producer/ seller Kienzle Apparate GmbH (today VDO).

Related Research Articles

Odometer Instrument used for measuring the distance traveled by a vehicle

An odometer or odograph is an instrument used for measuring the distance traveled by a vehicle, such as a bicycle or car. The device may be electronic, mechanical, or a combination of the two (electromechanical). The noun derives from ancient Greek ὁδόμετρον, hodómetron, from ὁδός, hodós and μέτρον, métron ("measure"). Early forms of the odometer existed in the ancient Greco-Roman world as well as in ancient China. In countries using Imperial units or US customary units it is sometimes called a mileometer or milometer, the former name especially being prevalent in the United Kingdom and among members of the Commonwealth.

Intelligent transportation system Advanced application

An intelligent transportation system (ITS) is an advanced application which aims to provide innovative services relating to different modes of transport and traffic management and enable users to be better informed and make safer, more coordinated, and 'smarter' use of transport networks.

Tachometer Instrument measuring the rotation speed of a shaft or disk

A tachometer is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analogue dial, but digital displays are increasingly common.

Automotive safety Study and practice to minimize the occurrence and consequences of motor vehicle accidents

Automotive safety is the study and practice of design, construction, equipment and regulation to minimize the occurrence and consequences of traffic collisions involving motor vehicles. Road traffic safety more broadly includes roadway design.

Vehicle insurance is insurance for cars, trucks, motorcycles, and other road vehicles. Its primary use is to provide financial protection against physical damage or bodily injury resulting from traffic collisions and against liability that could also arise from incidents in a vehicle. Vehicle insurance may additionally offer financial protection against theft of the vehicle, and against damage to the vehicle sustained from events other than traffic collisions, such as keying, weather or natural disasters, and damage sustained by colliding with stationary objects. The specific terms of vehicle insurance vary with legal regulations in each region.

Speedometer Speed gauge in motor vehicles

A speedometer or speed meter is a gauge that measures and displays the instantaneous speed of a vehicle. Now universally fitted to motor vehicles, they started to be available as options in the early 20th century, and as standard equipment from about 1910 onwards. Speedometers for other vehicles have specific names and use other means of sensing speed. For a boat, this is a pit log. For an aircraft, this is an airspeed indicator.

Usage-based insurance (UBI) also known as pay as you drive (PAYD) and pay how you drive (PHYD) and mile-based auto insurance is a type of vehicle insurance whereby the costs are dependent upon type of vehicle used, measured against time, distance, behavior and place.

Fuel economy in automobiles Distance travelled by a vehicle compared to volume of fuel consumed

The fuel economy of an automobile relates distance traveled by a vehicle and the amount of fuel consumed. Consumption can be expressed in terms of volume of fuel to travel a distance, or the distance travelled per unit volume of fuel consumed. Since fuel consumption of vehicles is a significant factor in air pollution, and since importation of motor fuel can be a large part of a nation's foreign trade, many countries impose requirements for fuel economy. Different methods are used to approximate the actual performance of the vehicle. The energy in fuel is required to overcome various losses encountered while propelling the vehicle, and in providing power to vehicle systems such as ignition or air conditioning. Various strategies can be employed to reduce losses at each of the conversions between the chemical energy in the fuel and the kinetic energy of the vehicle. Driver behavior can affect fuel economy; maneuvers such as sudden acceleration and heavy braking waste energy.

An event data recorder (EDR), similar to an accident data recorder (ADR) sometimes referred to informally as an automotive black box, is a device installed in some automobiles to record information related to traffic collisions. In the USA EDRs must meet federal standards, as described within the U.S. Code of Federal Regulations.

A regularity rally, also called time-speed-distance or TSD rally, is a type of motorsport rally with the object of driving each segment of a course in a specified time at a specified average speed. The rally is usually conducted on public roads, but sometimes includes off-road and track sections. Contestants usually compete in teams composed of an amateur driver and navigator. Teams usually start a regularity rally at fixed intervals, creating a field that is spread along the course.

Hubometer

A hubometer, or hubodometer or simply hubo, is a device mounted on the axle of an automobile or other land vehicle that measures distance traveled.

Drivers' working hours is the commonly used term for regulations that govern the activities of the drivers of commercial goods vehicles and passenger carrying vehicles. In the United States, they are known as hours of service.

Electronic instrument cluster

In an automobile, an electronic instrument cluster, digital instrument panel or digital dash for short, is a set of instrumentation, including the speedometer, that is displayed with a digital readout rather than with the traditional analog gauges. Many refer to it simply as a digital speedometer.

Intelligent speed adaptation (ISA), also known as alerting, and intelligent authority, is any system that ensures that vehicle speed does not exceed a safe or legally enforced speed. In case of potential speeding, a human driver can be alerted, or the speed reduced automatically.

Electronic on-board recorder

An electronic on-board recorder (EOBR) is an electronic device attached to a commercial motor vehicle, which is used to record the amount of time a vehicle is being driven. This is similar to the tachograph, and is the American equivalent of the digital tachograph used in Europe. Trucks in the European Union are required to have digital tachographs installed, and are securely monitored by government agencies. However, in Europe, the new digital tachograph which is considered secure, can be tricked with a round magnet placed by drivers over the connection to the transmission box. Usually they tie a rope to that magnet, and with a simple pull, the magnet will disengage and will show that the driver started moving about half an hour ago . The majority of carriers and drivers in the United States currently use paper-based log books. On January 31, 2011, the U.S. Federal Motor Carrier Safety Administration (FMCSA) proposed a rule requiring Electronic On-Board Recorders for interstate commercial truck and bus companies. The proposed rule covers interstate carriers that currently use log books to record driver's hours of service. The proposal would affect more than 500,000 carriers in the United States and carriers that currently use time cards would be exempt.

A vehicle tracking system combines the use of automatic vehicle location in individual vehicles with software that collects these fleet data for a comprehensive picture of vehicle locations. Modern vehicle tracking systems commonly use GPS or GLONASS technology for locating the vehicle, but other types of automatic vehicle location technology can also be used. Vehicle information can be viewed on electronic maps via the Internet or specialized software. Urban public transit authorities are an increasingly common user of vehicle tracking systems, particularly in large cities.

Electric vehicle warning sounds

Electric vehicle warning sounds are sounds designed to alert pedestrians to the presence of electric drive vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs) travelling at low speeds. Warning sound devices were deemed necessary by some government regulators because vehicles operating in all-electric mode produce less noise than traditional combustion engine vehicles and can make it more difficult for pedestrians and cyclists to be aware of their presence. Warning sounds may be driver triggered or automatic at low speeds; in type, they vary from clearly artificial to those that mimic engine sounds and those of tires moving over gravel.

A connected car is a car that can communicate bidirectionally with other systems outside of the car (LAN). This allows the car to share internet access, and hence data, with other devices both inside and outside the vehicle. For safety-critical applications, it is anticipated that cars will also be connected using dedicated short-range communications (DSRC) or cellular radios, operating in the FCC-granted 5.9 GHz band with very low latency.

Digital tachograph

A digital tachograph is a device fitted to a vehicle that digitally records its speed and distance, together with the driver's activity selected from a choice of modes.

Accident data recorder

The accident data recorder, is an independent electronic device that records before, during, and after a traffic accident relevant data and thus resembles a flight recorder.

References

Commons-logo.svg Media related to Tachographs at Wikimedia Commons